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About this book

This book presents the proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018), held on August 26-30, 2018, in Florence, Italy. By highlighting the latest theories and models, as well as cutting-edge technologies and applications, and by combining findings from a range of disciplines including engineering, design, robotics, healthcare, management, computer science, human biology and behavioral science, it provides researchers and practitioners alike with a comprehensive, timely guide on human factors and ergonomics. It also offers an excellent source of innovative ideas to stimulate future discussions and developments aimed at applying knowledge and techniques to optimize system performance, while at the same time promoting the health, safety and wellbeing of individuals. The proceedings include papers from researchers and practitioners, scientists and physicians, institutional leaders, managers and policy makers that contribute to constructing the Human Factors and Ergonomics approach across a variety of methodologies, domains and productive sectors.

This volume includes papers addressing Musculoskeletal Disorders.

Table of Contents

Frontmatter

Workshop: How to Diagnose and Treat a Work Related Musculoskeletal Disorder?

WRMSD is the commonest occupational health condition across the world. WRMSDs can affect workers in the industrial, commercial, healthcare, hospitality, and service sectors. Occupations at high risk for WRMSDs include machine operators, parts assembly operators, manual and agricultural labourers, nurses and other healthcare professionals, computer or visual display unit users, typists, and musicians. Diagnosis of WRMSD can be controversial and challenging, especially since soft tissue evaluation requires specialised manual skills not usually provided in medical training. Symptoms of WRMSD are often poorly localised, nonspecific, and episodic. Accurate diagnosis helps determine the most appropriate treatment and protects the worker from treatments that are ineffective, unwarranted, or unnecessarily invasive (54%). The current best practices regarding investigations, treatment of WRMSD using a staged, comprehensive, multi-disciplinary protocol, and criteria for return to work will be discussed. Common WRMSDs like Myofascial Pain Syndrome, Thoracic Outlet Syndrome, Fibromyalgia Syndrome, Tendinopathies, Compressive Neuropathies and Disc Disorders will be covered.

Deepak Sharan, Joshua Samuel Rajkumar, Jerrish A. Jose

How to Perform an Ergonomic Workplace Analysis?

Work related musculoskeletal disorders (WRMSD) are one of the commonest causes for morbidity among workers and are associated with significant financial and social burden. The use of a methodical, step-by-step approach and validated, simplified risk estimation tools which can be used even by non-experts in workplaces with limited resources is necessary to evaluate conditions of biomechanical overload and prevent WRMSDs. The work-related risk factors are psychosocial, physical, personal, organisational, environment etc. Identification of potential risk factors is an important component in preventing WRMSD and Ergonomic Workplace Analysis (EWA) plays a key role in it. EWA is a process where the ergonomic risk factors are evaluated using various validated tools. An EWA usually consist of 12 steps which included collection of personal information, work details, subjective analysis questionnaires, psychosocial information, vital sign assessment, metabolic assessment, assessment of work effort and fatigue, postural evaluation, other specific evaluations, environment details which is followed by analysis, recommendation and then follow up evaluations

Deepak Sharan, Jerrish A. Jose, Joshua Samuel Rajkumar

MSDs Reducting with an Innovative Approach of Professional Gestures - Collaborating 15 Years with Faurecia Group

In a lot of our physical activities, our motions are usually initiated from the upper limbs and superficial muscles. Therefore, the generated power is scattered, erratic and very uptight. The perception of movement and the awareness of trajectories are weak. This way of moving causes MSDs that mainly affect the upper limbs. A lot of models for investigation of works disorders gives guidelines for upper limbs This is an important in the beginning but for us ergonomists, we have to make a real breakthrought.

Eric Caulier, Georgette Methens-Renard

Systematic Reviews as Evidence-Base for Dutch Guidelines to Assess Musculoskeletal Disorders as Occupational Disease: Examples of Shoulder, Knee and Low Back Disorders

In The Netherlands, occupational physicians are obligated to report occupational diseases (ODs) to the Netherlands Center for Occupational Diseases (NCOD). Evidence-based occupational disease guidelines have been developed for musculoskeletal disorders. At the moment, the NCOD has 23 guidelines for work-related musculoskeletal disorders. The aim of this session is to explain the development of these criteria for the work-related assessment of subacromial pain syndrome, knee osteoarthritis and non-specific low back pain in the Netherlands. To enhance the application of these guidelines for ergonomic professionals, the exposure-criteria for the same job demands are categorized for instance in exerted hand force, movement, posture and vibration. When a job demand exceeds the exposure criteria, evidence is available that a worker has an increased risk of developing an occupational disease. For example, hand-arm elevation (≥60° 1 h/day), hand force (≥10% maximum voluntary force exertion) and hand-arm vibration (>2.5 m/s2 8 h/day) are examples of exposure criteria for the work-relatedness of subacromial pain syndrome. International comparison of OD exposure criteria and knowledge about corresponding effective preventive measures could be enhanced by scientific collaboration in defining evidence-based work-related diagnostic criteria and guidelines. The knowledge could be anchored in instruments and tools for ergonomic professionals.

Henk F. van der Molen, Monique H. W. Frings-Dresen, P. Paul F. M. Kuijer

The Effect of Short Time Computer Work on Muscle Oxygenation in Presence of Delayed Onset Muscle Soreness

We aimed at investigating the effect of a short time low load repetitive task on the local muscle oxygenation kinetics in presence of delayed onset muscle soreness. Computer work was investigated as a model of low load repetitive task. Nine healthy male subjects participated in an experimental protocol consisting of a rest period and two blocks, each including two maximum voluntary contractions (MVC) of isometric bilateral shoulder elevation and a computer work session with 2 or 5 min duration between the MVCs in each block. Then a set of unaccustomed eccentric exercise (ECC) of shoulder elevation was implemented to induce delayed onset muscle soreness (DOMS) in the trapezius muscle. Identical experimental blocks were performed immediately and 24 h after ECC. Local tissue saturation index (TSI) was continuously recorded over upper trapezius throughout the experiment. TSI parameters such as mean TSI at rest, during computer work as well as TSI drop, recovery and their descending and ascending slopes were computed following the MVCs. TSI drop and recovery and their corresponding descending and ascending slopes were reduced immediately after ECC (p < 0.05). The computer work caused an increase in TSI at rest prior to the MVCs (p < 0.05) and elevated oxygen consumption (p < 0.05). The observed changes in oxygenation kinetics seemed to appear after a strenuous exercise and they do not seem to be affected by the presence of DOMS. However, computer work as a model of low load repetitive task caused increased oxygen consumption in a following bout of muscle contraction.

Afshin Samani, Ryan Godsk Larsen

Effects of Shift Work on Knee Pain and Knee Osteoarthritis Among Retired Chinese Workers

Objectives: To evaluate the association between shift work with the risk of knee pain and knee osteoarthritis (KOA), we studied 13,906 retired workers from the Dongfeng-Tongji cohort.Methods: Physical examinations and face-to-face interviews were performed. Knee pain was diagnosed by self-reported pain or stiffness. Clinical KOA was diagnosed from knee pain complains and clinical X-ray radiographs. Occupation history including work content and shift work experience in each job was collected from questionnaires.Results: The prevalence of knee pain and clinical KOA was 39.0% and 6.7%, respectively. After adjusting for potential confounders, shift work was independently associated with elevated risk of knee pain (OR 1.24, 95% CI 1.15–1.33) and clinical KOA (1.15, 1.01–1.32). Such associations remained stable in stratified analyses by age, gender, BMI, work postures, or chronic diseases. Additionally, in comparison with daytime workers, the risks increased with prolonged duration of shift work, the ORs (95% CI) of knee pain for participants with 1–9 years, 10–19 years, and ≥20 years of shift work were 1.20 (1.08–1.33), 1.26 (1.14–1.40), and 1.26 (1.12–1.40), and ORs (95% CI) of clinical KOA were 1.06 (0.87–1.30), 1.15 (0.94–1.40), and 1.26 (1.02–1.56). However, the effects of shift work on knee gradually reduced with the extended duration of leaving shift work.Conclusions: Shift work might be independent risk factor for knee pain and clinical KOA among the retired workers.

Min Zhou, Dongming Wang, Yanjun Guo, Weihong Chen

Financial Impact and Causes of Chronic MSD Cases in Malaysia Based on SOCSO Claims Record

Musculoskeletal disorder (MSDs) are major occupational health issues among the private sector and government. This paper analyzed total direct cost being paid by the Social Security Organization of Malaysia (SOCSO) to the Malaysian workers due to musculoskeletal disease. Total direct cost consists of compensation cost, return to work and rehabilitation cost, and medical cost. The objectives of this study are (1) to determine the total direct costs incurred as a result of cases of chronic musculoskeletal injuries approved by SOCSO from 2010–2014. (2) To examine the age category imposed for the total average cost on the highest MSDs claims for the four categories setting. This study has utilize data provided by Social Security Organization of Malaysia (SOCSO) on occupational diseases and adopt top-down approach. The claims data is limited to MSD reported between 2009 until 2014. A total of 416 claims related to MSD has been analyzed. All the category recorded the highest total direct cost for types of industry, types of injury, causes of accident and type of body part. Then age claimant is identified from total average cost earns from the highest total direct cost for four categories. Manufacturing industry, strenuous movement, sprain and strain and back are recorded as high total direct cost with bear cost of RM 5,181,282.34 (n = 185), RM 7,088,839.51 (n = 264), RM 8,753,975.13 (n = 335), RM 5,526,590.69 (n = 209) respectively. Then the age 35–44 is recorded as the high total average cost for this four parameter. This study will provide basis for future studies and intervention on MSD related injuries in working environment in Malaysia.

Raemy Md Zein, Jafri Mohd Rohani, Norsheila Zainal Abidin, Ismail Abdul Rahman

Musculoskeletal Symptoms in Midwives and Work-Related Contributory Risk Factors

This paper presents an exploration of work related musculoskeletal symptoms and contributory factors in midwives. Data were collected with a survey (n = 635) and interviews (n = 15). The survey results showed that the majority of midwives (92%) reported musculoskeletal discomfort within the last 12 months, most commonly for the low back, neck and shoulders. The suggested main contributory factors were awkward working positions, increased work load with longer shifts and fewer breaks, and less support leading to defensive practice. The results of this research indicate that musculoskeletal symptoms are a problem among midwives with serious impacts. Strategies should be developed to manage risk factors to improve patient safety and staff well-being.

Kubra Okuyucu, Sue Hignett, Diane Gyi, Angie Doshani

Multitask Analysis of UL Repetitive Movements by OCRA Method: Criteria and Tools

The OCRA Checklist is one of the tools of the OCRA method for assessing risk associated with repetitive movements of the upper limbs. Task rotation is when a worker alternates between two or more tasks during a certain period of time (i.e.: a day, a month, a year). The multitask analysis process by the OCRA Checklist involves the following steps: 1 - Determine the full task rotation period: daily up to yearly; 2 - Identify repetitive tasks performed in the period; 3 - Use the OCRA checklist to calculate the “intrinsic” score for each task as if it was performed for the entire period; 4 - Analyse tasks and scores with respect to real time exposure and apply two alternative computational models: Time-Weighted Average and Multitask Complex. While, in the industrial sectors, tasks rotate often in a similar way every day and consequently the previous procedures could be easily applied, in some productive sectors exposure assessment is much more complex being characterized by the presence of several tasks over periods longer than a day (weekly, monthly, yearly). In general the study of these conditions are based on the use of the Checklist OCRA and on adaptations of the two multitask analysis models.

Occhipinti Enrico, Colombini Daniela

Application Study: Biomechanical Overload in Agriculture

This project has the goal of defining the basic criteria for producing a guide (Technical Report-TR) for the specific use of the ISO 11228 series, of ISO 11226 and of ISO TR 12295 [4–8] in the agricultural sector. Specifically, the project is aimed at providing the potential users with additional information on how to use existing standards in a world widespread working sector as agriculture where, also if with different characteristics, biomechanical overload is a relevant aspect, WMSDs occurrence is very high and where specific preventive actions are needed.One of the main goals is therefore to provide all users, and particularly those who are not experts in ergonomics, with criteria and practical procedures for a correct risk analysis. Method as checklist OCRA, NIOSH, carrying, push and pull evaluation are used, applied to annual multitask analysis, through the use of original software by EPM IES, free download from www.epmresearch.org

Daniela Colombini

A Study on Effects of Muscle of Lower Limb Associated with Whole-Body Vibration

Long-term exposure to whole-body vibration in the workplace will increase the chances of lower back pain, spinal disc herniation, and other diseases. However, many studies have also indicated that vibration stimulation, often used in physical therapy, clinical treatment, and muscle strength training, has a variety of positive effects for the human body.A commercially available electric vibrating machine was chosen, and 20 subjects were recruited to statically stand on the vibration platform with knee flex at different angles (0o, 60o, 90o), and to dynamically stand (squatting and rising) on the platform, while being exposed to different vibration frequencies (0 Hz, 20 Hz, 35 Hz, 50 Hz). The experiment used surface electromyography to assess the effects of posture and frequency on the neuromuscular activation. Each subject was asked to rate the perceived exertion on three monitored muscles (gastrocnemius, rectus femoris, vastus lateralis).The results showed that the knee flex angle had a significant effect on the muscles of the lower limbs, especially the thigh muscles, which were regarded as the support for body weight, and that the most obvious impact on the lower limb muscles was on the calf muscles during whole-body vibration. Surface EMG signals detected in dynamic posture were generally higher than those in static posture; however, through the subjective perception and assessment of subjects, we found that the scores of the two situations were quite close. The study results showed that the higher-frequency vibration activated muscles more easily. However, excessive fatigue would also result in injuries, a cause for caution and care.

Shih-Yi Lu, Xiang-An Cheng, Yen-Hui Lin, Cheng-Lung Lee

Work Postural and Environmental Factors for Lower Extremity Pain and Malalignment in Rice Farmers

In many Southeast Asian Countries, most tasks of the rice cultivation rely heavily on manual labor and require prolonged working in muddy terrain. Due to the lack of comprehensive ergonomic assessment and interventions, a series of studies were conducted to examine work postural and environmental factors contributing to lower extremity (LE) pain and malalignment in Thai rice farmers. This paper evaluates the collective results of our previous studies, which can be divided into two stages. The initial stage included a survey of pain perception and physical examination of LE alignment to specify the most problematic LE parts in a large group of 250 farmers, revealing that farmers generally perceived elevated hip pain. However, physical examination identified a high prevalence of foot pronation and knee valgus. A subsequent detailed analytical stage, conducted to identify factors of LE pain on a smaller group of 30 farmers, included two-stage ergonomic risk assessment and investigation of effects of muddy work terrain in different laboratory settings. The ergonomic assessment results indicated the planting process to pose the highest risk for LE injury, specifically leading to perception of knee pain induced by motion and posture factors, and foot pain induced by force exertion. Experiential results showed muddy ground to induce significantly higher force on knees and higher levels of knee and ankle muscle exertion. The findings suggest that further development of interventions should focus on reducing awkward posture and muscular exertion due to mud resistive force, particularly for knee and foot during the planting process.

Manida Swangnetr Neubert, Rungthip Puntumetakul, Usa Karukunchit

Multitask Analysis of Whole Body Working Postures by TACOs: Criteria and Tools

Work-related musculoskeletal disorders (WMSDs) are very common in different professional profiles due to the awkward postures maintained during their work.TACOs (Timing Assessment Computerized Strategy) method enables to assess this risk starting from work organizational study to identify the various tasks making up the job and it offers criteria for calculating scores even in highly complex scenarios where individuals perform multiple tasks sometimes over cycles lasting longer than one day (weekly, monthly, yearly).

Marco Tasso

Repetitive Manual Tasks Risk Assessment Among Supermarket Workers: Proposal of an Analysis Model

Introduction: Although the risk of upper limbs repetitive movements of cashier workers is clear in the scientific literature, there are still very few studies providing a comprehensive risk assessment for all supermarket jobs regarding musculoskeletal conditions due to repetitive movements.Methods: An organizational analysis of 5 supermarkets was carried out onsite to determine the duration and content of the shifts, i.e. to identify which tasks entail a potential biomechanical overload and how they are assigned to homogeneous groups of workers. A total of 67 tasks were identified and analyzed. Each individual task carried out by supermarket staff was analyzed and filmed. The videos were later assessed using the OCRA checklist, for both the right and left arm, to calculate the intrinsic task risk.Result: Based on the evaluations, risk of upper limb musculoskeletal disorders is often “medium” and sometimes “high” (e.g. deli counter and butcher) among full-time workers; for part-time workers risk is often medium/low red or borderline (yellow).Discussion: The analysis of the exposure to repetitive movements should be performed based an exhaustive organizational analysis. This kind of study will contribute to manage this risk and improving working conditions in an effective way. More research is needed to identify the best mathematical model to compute the weekly risk score.

S. Tello-Sandoval, E. Alvarez-Casado, D. Colombini

Neck Postures During Smartphone Use in University Students and Office Workers: A Field Study

Office workers and university students are known to suffer from neck pain as they are frequent users of electronic devices. The present study utilized inertial motion sensors to examine real-time spinal kinematics in office workers and university students for 3 h in their natural working/studying environment. Office workers (10 males, 10 females) and university students (11 males, 11 females) were recruited by convenience sampling. Their mean ages were significantly different (Workers: 40.8 ± 8.5 years; Students: 21.5 ± 2.6 years). Five inertial motion sensors (Noraxon myoMotionTM) were attached firmly onto the occipital protuberance, and the spinous processes of C6, T3, T12, and the sacrum, respectively, yielding angular displacements of the cervical, upper thoracic, lower thoracic and lumbar segments. The mean postural angles and the number of variations (zero crossings per minute) were analyzed. Self-reported neck pain score was higher in office workers (4.1 ± 3.7 on a 0–10 numeric scale) than that in students (2.3 ± 2.0, P = 0.076). Students adopted significantly greater degrees of lumbar flexion compared with office workers. Conversely, office workers tended to adopt slightly larger neck postural angles than students. Similarly, there was no significant between-group difference in zero crossings for the different spinal segments. Multivariate regression analyses showed that interaction of posture and duration of smartphone use were factors significantly contributing to musculoskeletal symptoms in students (P < 0.001), while age and gender were significant risk factors for symptoms in office workers (P = 0.001).

Grace Szeto, Daniel To, Sharon Tsang, Arnold Wong, Jay Dai, Pascal Madeleine

Handheld Mobile Devices—How Do We Use Them at Work? A University Case Study

The use of handheld mobile devices (tablets and smartphones) is common among the general population. It is acknowledged that the use of handheld mobile devices exposes users to the recognized ergonomic risk factors of duration, repetition, and awkward and static postures; however, the nature of this exposure is currently poorly defined. This cross-sectional survey collected information about the use of smartphones and tablets concerning: type of devices, duration of use, duration of work-related tasks, environmental settings, hand-grip and tablet position, and musculoskeletal discomfort. Three hundred and ninety-eight (398) university employees and research students responded to the survey. The survey results highlighted that the use of smartphones differs from the use of tablets, with differences noted for postures adopted, duration of use, location of use, tasks undertaken, environmental settings, and hand-grip and tablet position. The results emphasized the potential ergonomic risks that workers are exposed to during the use of smartphones and tablets especially in relation to posture, duration, and environmental settings.

Abdullah Alzhrani, Margaret Cook, Kelly Johnstone, Jolene Cooper

Investigation of Sensitivity of OWAS and European Standard 1005-4 to Assess Workload of Static Working Postures by Surface Electromyography

The present study investigates the sensitivity of the Ovako Working Posture Analyzing System (OWAS) and European Standard 1005-4 for an assessment of work load of static working postures. Therefore a comparison of these methods with surface electromyography (EMG) is conducted. For this purpose muscle activity of eight muscles is captured in a laboratory study (n = 24) during 16 different static working postures. The results are compared with risk assessment categories of OWAS and European Standard 1005-4. A repeated–measures analysis of variance revealed a significant increase of muscle activity with increasing back angles and shoulder angles. However, this increase of muscle activity and the associated increase of musculoskeletal injury risk are not represented by OWAS and European Standard 1005-4 to the same extent. Thus, for an investigation of static working postures European Standard 1005-4 is more recommendable to identify musculoskeletal injury risk, since the high variance of muscle activity in the investigated working postures is represented better by the spread of three zones of European Standard 1005-4.

Tobias Hellig, Alexander Mertens, Christopher Brandl

Low Back Pain (LBP) and Physical Work Demands

Low back pain (LBP) is a common occupational health complaint and an important public health concern. Analyzing the association between physical demands at work and occupational outcomes can be useful for improving LBP prevention. In this study, workers filled out a questionnaire gathering data on socio-demographic and work-related characteristics, general health, LBP (episodes in the last 12 months, pain severity and intensity), and other occupational hazards related with physical demands (DMQ). 735 workers answered the questionnaire (male n = 359). They worked in different sectors. 507 (69%) reported LBP in the last year. The highest proportion of subjects with >6 episodes of LBP per year was found among public services (31.8%) and the lowest among administrative working in offices (10.3%). Most workers reported having sedentary-type work (39%), 34% a low/moderate physical intensity one, and 27% a highly physically demanding one. Results of logistic regression showed that, after adjusting for age, gender and sector: sedentary work (vs. high work intensity) was associated with a lower likelihood of having 3 to 6 LBP episodes per year (OR = 0.4; 95%CI 0.2–0.8), and >6 LBP episodes per year (OR = 0.5; 95%CI 0.3–0.9); low/moderate work intensity (vs. high work intensity) was also associated with a lower likelihood of having 3 to 6 LBP episodes per year (OR = 0.5; 95%CI 0.3–0.9) and >6 LBP episodes per year (OR = 0.6; 95%CI 0.3–1.0). Findings suggest that occupational high physical demands are associated with a higher likelihood of presenting LBP. For Occupational Health Services these results may contribute to design and assess better LBP prevention programs.

F. Serranheira, M. Sousa-Uva, F. Heranz, F. Kovacs, A. Sousa-Uva

The Revised ISO Standard 11228-1 on Manual Lifting, Lowering and Carrying: Special Focus on Extensions of the Revised NIOSH Lift Equation and a Strategy for Interpretation

This short paper summarizes a number of the revisions to the ISO 11228-1 standard on manual lifting, lowering and carrying related to the use and extensions of the Revised NIOSH Lifting Equation (RNLE). The extensions allow the RNLE to be applied to more complex multiple lifting tasks that are commonly found in industry and warehousing. Also reviewed is a recommend approach to interpreting the calculated result (LI, CLI, SLI, VLI) of the RNLE and its extensions.

Robert R. Fox

The Influence of Physiological Breaks and Work Organization on Musculoskeletal Pain Index of Slaughterhouse Workers

Beef cattle and the meat processing chain are of great economic importance in Brazil, since they are responsible for creating thousands of jobs. Nevertheless, the issue of health and safety of the sector’s workers is a major problem given the high number of accidents at work and workers in sick leave, as a consequence of working at low temperatures, doing repetitive tasks, and carrying weights. In light of that, this article aims at identifying the association between musculoskeletal pains and discomforts and the implementation of a system of break periods and task rotations in the slaughter sector of a cattle slaughterhouse. The method employed consisted of direct observation, interviews with workers, and the application of ergonomic analysis methods. Results show that the lack of guidance in the implementation of task rotation still generates complaints, discomforts, and sick leaves. Finally, we developed a functional task rotation plan grounded on the analysis of work stations’ risks.

Roberta Schwonke Martins, Fernando Gonçalves Amaral, Marcelo Pereira da Silva

An Investigation of the Maximum Acceptable Weight of Lift by Indonesian Inexperienced Female Manual Material Handlers

The purpose of this study was to investigate the maximum acceptable weight of lift (MAWL) by Indonesian inexperienced female manual material handlers. Twenty-one females who were selected based on their physical activity categories voluntarily participated in this study. The participants were asked to determine their MAWLs using the psychophysical method for the lifting tasks at two different lifting frequencies: one lift/5 min and 4 lifts/min. The participants’ heart rate was also recorded to be utilized for investigating the physiological responses while lifting the obtained MAWLs. The obtained MAWLs were also compared to the MAWLs of other study populations, using published data. As the results, two-way analysis of variance test result revealed no significant effect of physical activity category on MAWL (p = 0.890). On the other hand, a significant effect on MAWL for the lifting frequency was observed at p < .001. The comparison of MAWLs obtained in this study to other studies showed that no significant differences on MAWL were found between Indonesian and Chinese inexperienced manual handlers for the lifting tasks at one lift/5 min. The significant differences on MAWL were observed between Indonesian inexperienced and American experienced female manual handlers. However, no significant differences were observed for the lifting tasks at 4 lifts/min. Furthermore, the physiological data analysis revealed that the energy expenditures required for lifting at one lift/5 min was significantly less than the physiological limit, while those of lifting at 4 lifts/min was significantly higher than the limit. The results of this study might be utilized as consideration for determining the safety lifting limit for Indonesian inexperienced female manual material handlers.

Ardiyanto Ardiyanto, Dhanaya A. Wirasadha, Novi W. Wulandari, I. G. B. Budi Dharma

The Effect of the Lower Extremity Posture on Trunk While Sitting

The goal of this study was to investigate the interactions between upper extremity and lower extremity in sitting postures. Ten healthy participants were recruited from the university population, and were asked to sit on a chair with six different lower extremity postures (2 trunk-thigh angles, 3 knee angles). The head, trunk and lower extremity postures were captured by using fourteen motion trackers, and used to calculate the head flexion angle, thoracic flexion angle, lumbar flexion angle, pelvic flexion angle, and shoulder angle. Results showed the effects of changes in the trunk-thigh angle and the knee angle on all dependent measures. First, the bigger trunk-thigh angle (135°) showed better lumbar lordosis, smaller head flexion angle, and less rounded shoulder as compared to the 90° trunk-thigh angle. In addition, the current study revealed that the bigger the trunk-thigh angle, the better the whole trunk postures including the better lumbar and thoracic lordosis, less flexed head, and less rounded shoulder. Second, the bigger knee flexion angle negatively influenced on all trunk posture measures, suggesting that the extended knee joint tightens hamstring muscles and pulls the pelvis backward, and finally results in the bad trunk posture such as less lordotic lumbar and thoracic postures, more head flexion angle and more rounded shoulder angle. On this basis, the office chair should be designed under the consideration of the lower extremity postures such as the position of foots, the knee supporter, and the seat inclination angle.

Sangeun Jin, Seulgi Kim, Seong Rok Chang

Occupational Diseases of the Musculoskeletal System – The Situation in Germany

The reporting and acceptance of a musculoskeletal occupational disease in Germany is based on an extensive procedure.An admissible occupational disease has to be named on the list of occupational diseases defined by a medical specialist committee of the Federal Ministry of Labour and Social Affairs. This committee defines the scientific guidelines for reporting doctors. For most of the occupational diseases these guidelines include information about occupational exposures or defined occupational groups. For the acceptance of an occupational disease, more elaborate criteria have to be fulfilled.In Germany, there are currently fourteen occupational musculoskeletal diseases. Three more occupational diseases are currently being discussed by the medical specialist committee. Disc related diseases of the lumbar spine are the occupational diseases for which there are the most reports. The scientific guidelines include tables with loads and forces. The criteria for acceptance include duration of exposure, frequency of exposure, and kind of exposure (heavy loads, trunk inclination). Only few of the initially reported cases are finally compensated. The identification and compensation of occupational diseases in Germany started as soon as 1885 and developed into a complex process. New input by international comparisons will be beneficial for the future discussion.

Elke Ochsmann

Motor Control with Assistive Force During Isometric Elbow Flexion

In the modern society, an assistive/powered suit has been developed to enhance the limb and trunk movements by mechanical force. The effective output of assistive products needs cooperation between the users, that is, human beings and the machine. The present study investigated the motor control of external forces that assist with physical exertion. Sixteen adult male participants performed isometric elbow flexion under two conditions of submaximal workload (20% and 40% of the maximal voluntary contraction) and four levels (0%, 33%, 67%, and 100%) of assistive force. The electromyographic (EMG) activity of the agonist and antagonist muscles (biceps and triceps, respectively) and rating of perceived exertion decreased with increased levels of assistive force under both workload conditions. At the lower level of assistance (33%), the EMG amplitude of the biceps was near the expected amplitude, which denotes that the participants made good use of the assistive force. However, at the higher level of assistance (100%), it was far from the expected values at both workload levels. These results suggest that the effectiveness of assistive force changes according to the level of workload and assistive force, and that various human physiological regulations and motor control would be required during cooperative work with assistive force.

Satoshi Muraki, Keisuke Hayashi, Nursalbiah Nasir, Ping Yeap Loh

A Focus on Dynamic Work Rather Than Sit or Stand Postures

The introduction of sit-to-stand workstations has resulted in the workplace community debating if standing is now the alternative to sitting at work. This debate is not well founded when the benefits of frequent changes in posture and using blood flow to maintain physical and cognitive health is the key outcome required. The term “dynamic work” should be the focus of the debate to encourage workers to change their working postures and activities to generate greater blood flow and dissipate static muscle loading. This should be discussed within a broader health debate in relation to the prevention of cardio vascular and obesity for sedentary workers. This is part of a focus on general health and wellbeing at work. Dynamic work is not about sitting or standing; it includes both of these postures as well as a broader understanding of the job design. A review of workers activities in post occupancy assessments of new office fitouts indicated that approximately 50% of workers to do not adjust their sit-to-stand workstations but leave it at a seated height at all times. These workers explained that their job design requires them frequently to change posture including getting up and walking around. They achieve the benefits of dynamic work through their multi task job design. Approximately 40% indicated that they will use the adjustment mechanism to change the workstation height between sitting and standing during the day however they were less likely to use the adjustment mechanism if it was noisy or slow to adjust. The actual timing and duration of the sitting or standing depended on their physical, cognitive and psychosocial needs of the worker. Findings also revealed that approximately 10% of workers preferred to stand at their workstations all the time. This cohort of people included workers with injuries who indicated that prolonged sitting aggravated their condition. It also included workers who regularly sat in meetings and preferred to stand when they returned to their workstation for a change in posture. There were also injured workers who use the sit-to-stand adaptor units on their fixed height workstations if they were recovering from an injury. Evidently the design of some adaptor units presented MSD risks due to the amount of force and the elevation of the shoulders required to adjust these unit. In relation to training it was found that the introduction of sit-to-stand workstations required specific guidance on how to achieve dynamic work. The training should also develop skills to relieve lower back and lower limb fatigue from prolonged standing. This is particularly important when the hands are in front of the body’s centre of gravity to work on a keyboard and mouse on the work surface. Further research is required pre and post relocation to sit-to-stand workstations to assess the health and wellbeing impact on the workers as well as the impact on their productivity and cognitive demands.

David Caple

Cognitive and Psychosocial Assessment of Sit or Stand Workstations

The biomechanical benefits of changing posture from sitting to standing are evident from the research on prevention of musculoskeletal disorders. However, the decision for workers who choose to sit or stand is also related to the cognitive and psychosocial needs in their work area. Research in office areas who have provided sit-to-stand workstations showed that the choice to stand in a team environment where other team members are sitting is often influenced by the team communication requirements. The workers indicated that maintaining eye contact with each other while discussing issues influenced their decision to adopt a standing position as a group and if all members were sitting then the decision to sit rather than stand was the general outcome. Further, where adjustment was available in both the workstation and chair design, the workers made necessary adjustments to maintain similar eye heights rather than to suit their individual anthropometry needs. Their ability to see and hear each other was assessed as more important from a cognitive and psychosocial perspective in these team settings than anthropometry. In individual settings such as focus rooms or enclosed offices where the worker is alone, they were more likely to adjust their workstation based on their physical requirements. If they spend much of their day in meetings where they are sitting, they use the time back at their workstation to stand whilst processing emails. However if they stand and walk a lot in their work, they choose to sit at the workstation as a break. Furthermore, it was found that the activity undertaken by the worker also influenced their decision to sit or stand. For example, when performing activities requiring moderate levels of concentration such as talking on the phone or writing emails, they were more likely to stand than if they were performing a task requiring focused attention such as typing a report. Thus for tasks requiring greater concentration, their preferred working position was sitting, as they were less likely to be distracted by others moving around the office. It is evident that the cognitive and psychosocial demands of the workplace will influence the utilization of sit-to-stand workstations as much or even more than the physical demands.

David Caple

Validation and Comparison of Three Positioning Protocols of Inertial Measurement Units for Measuring Trunk Movement

Postures and movements of the trunk are of ergonomic concern when evaluating the risks at work. Technical measurement methods can be used for measurements of trunk movements for long duration with high accuracy, and are therefore increasingly used in practice and research. However, currently there is no standardized protocol for the sensor placement for trunk measurement. Three placement protocols of inertial measurement units (IMUs), including placement on C7, T4 and sternum (St), in combination with S1 spinous process, were compared with an optical motion capture (OMC) system. Four subjects performed a movement test including forward to backward bending, sideward bending and twisting of the trunk, and a symmetrical lifting task. Root-mean-square differences (RMSDs) and Pearson’s correlation were calculated between the two systems. For the movement tests, the RMSDs of the forward inclination at the 10th, 50th and 90th percentiles from the three IMUs were all smaller than 7.3°. Larger differences were shown for C7 of the sideward inclination at 90th percentile (10.8°). Also for the twisting, larger differences were shown, especially for C7-S1 and T4-S1 (RMSD = 16.5° and 19.8°). For the lifting tests of forward inclination, St had the smallest differences compared to OMC (RMSDs < 4.1°), while slightly larger errors were found for C7 and T4 at the 90th percentile (RMSDs = 8.1° and 8.2°). Different positioning protocols seem to have a slightly different effect on the measurement accuracy of trunk movement. Considerations should be taken when comparing results across studies applying different protocols.

Liyun Yang, Dennis Borgström, Mikael Forsman

Work-Related Musculoskeletal Disorders and Risk Factors: A Cross-Sectional Study Among Chinese Flight Baggage Handlers

Objective: The aim of this study was to investigate prevalence of work-related musculoskeletal disorders (WMSDs) as well as the contribution of personal and ergonomic factors to the occurrence of low back pain among Chinese flight baggage porters, in order to provide them with valuable suggestions for intervention.Methods: Cluster sampling was conducted among flight baggage porters in an airport and a self-developed questionnaire was distributed to 550 flight baggage porters to collect information on musculoskeletal symptoms and relevant factors. Prevalence of work-related musculoskeletal disorders in different parts of the body were calculated. Univariate and multivariate logistic regression analysis were carried out to evaluate the influence of individual and ergonomic factors on the occurrence of regional musculoskeletal symptoms in the past 12 months.Results: The results showed that the prevalence of lower back pain, neck pain, hand/wrist pain and shoulder pain among these porters were 62.7%, 38.1%, 35.2% and 32.4%, respectively. The results of logistic regression suggested that factors as “smoking behavior”, “bending amplitude of back”, “turn around frequently”, “turn and bend at the same time frequently”, “exercise after work” and “labor intensity” were statistically correlated with low back pain, whose ORs were 1.699, 0.762, 1.716, 8.267, 3.645, 2.508, respectively.Conclusion: Airport porters are a group of workers at high risk of WMSDs. Some habitual and postural factors were recognized to be associated with low back pain. It is recommended to reduce labor intensity, train on proper postures, as well as develop good habits to prevent low back pain.

Jingjing Wang, Yang Cao, Xianning Jin, Nazhakaiti Maimaiti, Lihua He, Zhongbin Zhang, Zhongxu Wang, Wei Zhang

Comparison of Lift Use, Perceptions, and Musculoskeletal Symptoms Between Ceiling Lifts and Floor-Based Lifts in Patient Handling

Lifting equipment can reduce the risk of injury from patient handling, but its use has been far from optimal. This study examined frequency of lift use, perceptions about lift use and injury risk, and musculoskeletal symptoms by the type of available lifts (ceiling lifts vs. floor lifts only). The study analyzed data from a pooled sample of 389 California registered nurses who participated in two cross-sectional surveys in 2013 and 2016. Nurses who performed patient handling tasks and had patient lifting devices were included in the data analysis: 23% had ceiling lifts and 77% had floor lifts only. Lift use was more frequent among nurses with ceiling lifts than nurses with floor lifts only (use ≥ 50% of the time needed: 48% vs. 35%, p = 0.003). Perceptions about lift use were significantly more positive among nurses with ceiling lifts, in regard to safety for workers, safety and comfort for patients, and ease of use, access and storing; however, perceptions about time burden and injury risk were not significantly different. After controlling for survey year, the prevalence of major work-related musculoskeletal symptoms (moderate or severe symptoms that either occurred at least monthly or lasted one week or more) was significantly lower among nurse with ceiling lifts than those with floor lifts only for low back pain (OR = 0.52, 95% CI 0.30–0.89) and shoulder pain (OR = 0.59, 95% CI 0.35–0.99). The findings suggest that ceiling lifts are superior to floor-based lifts in multiple aspects, including better acceptance and use by nurses in patient handling, as well as being associated with reduced musculoskeletal symptoms, particularly in the low back and shoulders.

Soo-Jeong Lee, David Rempel

An International Survey of Tools and Methods Used by Certified Ergonomics Professionals

A survey of certified ergonomics professionals was conducted in 2017 by NIOSH researchers to understand the types of basic tools, observational methods, and direct measurement methods used by ergonomics professionals. This survey served to update findings from a previous survey of Certified Professional Ergonomists (CPEs) in the United States that was reported in 2005. The 2017 survey was expanded to include ergonomists certified in Australia, Canada, New Zealand, Great Britain, and Ireland. The 2005 survey content was used with the addition of technologies that were not available in 2005 (e.g., mobile devices and mobile applications) and tools likely to be of use by ergonomists outside the U.S. Overall, the participation rate was 34% (405 of 1,192 surveys that reached recipients) which was lower than the response rate of 53% for the 2005 survey. This may have been related to differences in the receipt format (postal versus internet) between the two surveys. The results for U.S. ergonomists were similar across both surveys for the most part, but there were also a number of differences. Differences across country/region were pronounced for some items, but similar for basic tools and several popular assessment tools. Overall, the results suggest that ergonomists gravitate towards inexpensive and efficient tools and methods. The strengths and limitations are discussed with suggestions for future research.

Patrick G. Dempsey, Brian D. Lowe, Evan Jones

Assessment of Muscular Strength for Male and Female Backpacking Task

Backpacking tasks are common. Back carrying, like many other manual materials handling (MMH) tasks, could result in muscular fatigue. Assessment of muscular strength recovery upon muscular fatigue is helpful to control musculoskeletal injuries and rest allowance management of the workplace. This research investigated back muscular fatigue for backpacking tasks of different loads via analyses of muscular strength decrease, recover, heart rate and subjective rating of physical exertion. Twelve adult participants (6 males and 6 females) were requested to carry a bag with 0%, 12.5%, and 25% of their body weights on their backs and walked on treadmill until they could no longer walk under three different speeds (2,4, and 6 km/hour) and two different ramp angles (0 and 10°). After the walk, the decrease of back muscular strength percentages (MVC) were measured in male and female subjects. In addition, the subjective rating on body fatigue was measured using the Borg RPE. It was found that back strength decreased after the carrying tasks, female subjects were more resistant to muscular fatigue than male subjects. The predictive model of RPE were been determined in Regression Equation, between the RPE score and MVC% are correlation coefficient. The RPE of results after the back-packing task were consistent with those of the muscular strength data.

Shui Cheng Tian, Ying Chen, Kai Way Li, Hong Xia Li

Interdisciplinary Association Between Biomechanical Analysis and Occupational Psychology: Challenges and Procedures

For preventing musculoskeletal disorders (MSDs), various types of intervention may be conducted, and in particular participatory ergonomics interventions. One of the key success factors in such interventions is the active involvement of the workers. The aim of this summary is to show how biomechanical analysis became part of occupational psychology methodology in order to help the workers (gravediggers in this case) to analyse their movements or “gestures” finely with a view to developing them. The construction of this interdisciplinary methodology in which the results of the biomechanical analysis were used by the workers as means for observing themselves, for comparing themselves with one another, and sometimes even for trying out different strategies for carrying out the gestures enabled gravediggers to be active in developing the gesture and thus in making progress towards preventing MSDs.

Adriana Savescu, Pascal Simonet

Impacts of Typing on Different Keyboard Slopes on the Deformation Ratio of the Median Nerve

Carpal tunnel syndrome is a symptomatic compression neuropathy of the median nerve as it travels through the wrist. Several factors such as wrist angle and finger posture cause a change of the intra-carpal tunnel pressure. Carpal tunnel syndrome is one of the most commonly reported work-related musculoskeletal disorders. Computer users are at higher risk of upper extremity musculoskeletal symptoms and work-related musculoskeletal disorders, since time spent on the computer is associated with a higher incidence of musculoskeletal disorders. Objective: to investigate the impact of typing at two keyboard slopes (0° and +20°) on the median nerve deformation ratio. Fifteen healthy young men (24.8 ± 2.3 years) were recruited to type using both 0° and +20° inclined keyboards. The participants performed four 30-min blocks of computer typing at 0° and +20° keyboard inclinations. The left wrist median nerve was examined with an ultrasound machine after each 30-min typing block. Two-way repeated analysis of variance was performed to examine any differences in the deformation ratio of the median nerve cross-sectional area. The four time blocks and two keyboard slope conditions (0° and +20° inclination) were used as factors. Continuous typing activity causes a significant increase in the median nerve cross-sectional area deformation ratio (p < 0.05). Ultrasonography examination of the median nerve following computer typing can be used to generate absolute measurements and deformation ratios. These measurements help provide a better understanding of the impact of typing tasks on the median nerve.

Ping Yeap Loh, Wen Liang Yeoh, Satoshi Muraki

Musculoskeletal Complaints in a Sample of Employees in a Tertiary Hospital: An Exploratory Preliminary Pilot Study

Introduction: Musculoskeletal disorders can cause impact in quality of life. This exploratory preliminary study aimed to describe musculoskeletal complaints in a sample of employees in a tertiary hospital.Methods: A university public hospital has 6114 employees that work in an emergency and outpatient units. There are several occupations with predominance of nurses, computer users, cleaning and cooking staff. A sample of ten workers was assessed by, socio-demographic sheet, The Nordic body pain map, SF-36 questionnaire, and Work Ability Index Questionnaire. Data were described in terms of frequencies by SPSS™.Results: The sample had predominance of women (80%), mean age of 49.3 years old, all have children, working as nurses, administrative and general services. 50% has less than 5 years of experience, most have two work shifts, few are active in terms of exercise routine, 70% use medication for pain, do not have a sitting or standing working position preference. Nordic questionnaire showed predominance in pain complaints in back, neck, shoulder and knee. SF-36 questionnaire presented mean scores for subdomains: functional capacity 68.56, physical aspects 68.75, pain 42.72, general health status 67.37, vitality 66.72, social aspects 81.25, emotional aspects 70.83 and mental health 67.2. The work ability index questionnaire the majority of the scores was classified as moderate (28–36).Conclusions: This study showed that besides high scores for SF 36 for these sedentary women, most use pain medication for musculoskeletal complaints and was identified necessity improvement of the work ability. There is need for future study focused on ergonomics and exercises.

M. C. R. Fonseca, F. P. F. M. Ricci, L. M. Gil, N. C. Silva, E. C. O. Guirro, R. R. J. Guirro, E. R. C. Lopes, L. R. Santos, R. I. Barbosa, A. M. Marcolino, V. R. Castro, T. M. Fifolato, H. Nardim, L. Mauad, K. S. Ferreira

Comparing the Strain Index and the Revised Strain Index Application in the Dairy Sector

Repeated forceful efforts, high muscular loads in the wrist flexor and extensor muscles and awkward hand positions during milking can contribute to wrist and hand diseases. Thus, evaluating the risk of biomechanical overload of milking parlor workers’ wrist with an accurate method is fundamental. Aims of the study were: (1) evaluating the wrist’s biomechanical overload in the milking routine subtasks: pre-dipping, wiping/stripping, attacking, post-dipping; (2) comparing the results obtained from Strain Index and Revised Strain Index methods application; (3) evaluating the quality of the approach, the concordance and the possible difficulties in applying and interpreting the two evaluation methods.3172 task cycles were evaluated on a population of fourteen male milking parlor workers using either SI or RSI.The results showed that both those index have not exceeded the limit value for pre-dipping and post-dipping tasks, whilst the wiping/stripping resulted to be the most risky for milking parlor workers for both RSI and SI methods. The RSI responded to the objectives of increasing the accuracy and the precision of the evaluation.

Federica Masci, Stefan Mandic-Rajcevic, Giovanni Ruggeri, John Rosecrance, Claudio Colosio

Human Factors Related to the Use of Personal Computer: A Case Study

The aim of this study was to determine and compare the ergonomic requirements in the use of desktop computers and laptops. For comparison, postures in the sagittal and transversal planes involved while performing a typing and editing task on a desktop and laptop computers were verified. Thus, a case study was conducted with a Brazilian male of medium height, who works around 20 h per week in a computer. Nine spherical markers of 2.5 cm in diameter were joined up with duct tape on the right side of the participant and the positions adopted by the subject were analyzed in the use of a desktop and a laptop computer, through direct observation and filming, using the videography technique. Among the most significant results, the use of desktop computers compared to laptops allows a more upright posture of the head and neck, as well as a more neutral posture of the shoulders, elbows and wrist. It is concluded that the use of desktop computers has lesser biomechanical demands since it showed angles closer to a neutral position and consequently having a lower risk of musculoskeletal complaints.

Fabíola Reinert, Raoni Pontes Caselli, Antônio Renato Pereira Moro, Leila Amaral Gontijo, Marcelo Gitirana Gomes Ferreira

Injury Claims from Steep Slope Logging in the United States

Logging is one of the most dangerous occupations in the United States. Although logging injuries within the U.S. have decreased over the last 20 years, injuries in this sector continue to exceed the rate of total recordable cases for all U.S. industries combined. Methods: Workers’ Compensation injury claim data from two workers’ compensation providers, which cover companies’ active in the logging industry of Montana and Idaho were obtained. All injury and fatality claims occurring from July 2010 to June 2014 were obtained from companies in the logging industry (NAICS 113). Injury claim data from each company contained information on demographics, variables related to the time, type and source, of injury, as well as the cost associated with each injury claim. Results: A total of 801 workers’ compensation claims were analyzed for the time period July 2010 to June 2015. The most common nature of injury were sprain/strain injuries, followed by contusions, and lacerations. Inexperienced workers (>6 months experience) accounted for over 25% of claims. Fatalities had the highest median claim cost ($274,411 USD). Conclusions: Injury prevention efforts in the logging industry within the Intermountain region should be focused on early training, engineering controls, and administrative controls; all designed to promote a culture and climate of safety, communication, and shared responsibility. The results of this project were used as the basis and justification for the development and implementation targeted safety interventions addressing the specific safety issues associated with logging in the Intermountain region.

John Rosecrance, Elise Lagerstrom

Evaluating the Effectiveness of Estimating Cumulative Loading Using Linear Integration Method

Exposure to cumulative loading is a significant risk factor in the development of musculoskeletal disorders (MSD). To better understand the dose-response relationship, it is critically to quantify the cumulative exposure. Different integration methods have been used in estimating cumulative loading (force or torque). The general objective of the integration methods has been to sum the independently calculated task exposure. Each task was calculated by multiplying the magnitude of the task loading times the task duration which is the “area under the loading curve”. An assumption of this linear integration model is that long-time exposure to low forces will result in a similar level of damage as relatively short time exposure to high forces. To evaluate the effectiveness of this model, three loading groups of eccentric exercise with the same “area under the loading curve” were performed by thirty participants (ten in each group). Maximum isometric voluntary contractions (MIVC) and relaxed elbow angle (REA) were collected before, immediately after, and 2, 4, 8 days after the exercise. The REA and MIVC changes after the eccentric exercise were significantly impacted by the loading group. It suggests that estimating cumulative loading using linear integration method may underestimate the impact of high force loading in terms of cumulative muscle damage.

Rong Huangfu, Sean Gallagher, Richard Sesek, Mark Schall, Gerard Davis

Capacity Index for Work, Psychosocial Risk of Work and Musculoskeletal Symptomatology in Workers of a Meat Processing Industry in Portugal

Objective: to identify the work ability perception, the psychosocial risk factors and musculoskeletal symptomatology among workers of a meat processing industry. Methods: the sample consisted of 74 subjects, 53 female (71,6%) and 21 male (28,4%), with a mean age of 41,9 years old (± 11,3). Data collection was based on a survey including the Portuguese Version of the Work Ability Index (WAI) and of the Copenhagen Psychosocial Questionnaire II (COPSOQ II) and of the Nordic Questionnaire. Results: concerning to work ability, the average value found was 39,38 (± 5,97), considered as good work ability. As to psychosocial risk factors, job insecurity presented critical results and favourable results were found in the scales: role clarity, rewards, social community at work, self-efficacy, work-family conflict and offensive behavior. As referring to self-reported musculoskeletal symptomatology, the region with the highest frequency of complaints was the cervical region with a prevalence of 40,5% (n = 30) of pain/discomfort, with average pain perception of 2,58 (± 3,45) points in the last 12 months. The Spearman correlation test between the variables age and cervical pain (rho = 0,433; p = 0) and between age and low back pain (rho = 0.240; p = 0.040) show that there is a relationship between these variables. Conclusion: The results of this study point to the need for preventive actions in the meat processing industry, such as those related to work organization (rotation of tasks, adjustment of the production rhythm) and to programs for the prevention of work related musculoskeletal disorders, especially among the women.

Inês Alessandra Xavier Lima, Antonio Renato Pereira Moro, Teresa Patrone Cotrim

Biomechanical Methodology for Evaluating Seat Comfort During Long Term Driving According to the Variation of Seat Back Angle

The aim of this study is to suggest a biomechanical methodology for evaluating seat comfort during long term driving with a use of driving stimulator. Recent modern car seat has become increasingly complexed and sophisticated with ongoing seat discomfort problems. Consumers’ demands for better seat comfort have also increased but most of them still choose car seats in the wrong way. Previous researches have recommended quantifying overall car seat discomfort based on questionnaire, EMG, and FEM etc. However, it is difficult to find successful objective evaluation methods in both in literature or in actual situations. Six males were recruited to participate in a laboratory study. All participants performed three trials separated by three different seat back angles (87°, 97°, and 107°) and each trial was conducted on different days. Each trial was consisted of 120 min of continuous driving on the driving simulator. Participants were recorded using Kinect v2 with a full body and pressure at both seat pan and back were measured to allow the investigator to analyze their postures. The results for each seat condition were analyzed through unpaired t-test in order to acquire statistical significance (P < 0.05). As expected, the overall discomfort rating increased over time, especially for neck and low back. Also, at 87° and 107°, the overall discomfort rating was higher than 97°. In addition, over time, we found an increase in pressure in both seat back and seat pan. These results suggest that a new biomechanical method could be an alternative for evaluating car seat comfort for long-term driving.

Dong Hyun Kim, Seohyun Kim, Sung Chul Kim, Sung Hyun Yoo, Young Jin Jung, Han Sung Kim

The Effects of Chair Inclination, Arm Support and Touch-Typing on Shoulder and Arm Muscle Activity in Computer Work

Aims. In an attempt to reduce the risk of work related musculoskeletal disorders (WRMD) in computer users, while maintaining comfort and functionality, different chair designs have been developed. This study aimed to determine the effect of chair inclination, arm support and touch-typing on muscle activation in the upper body.Methods. A randomized balanced design was used to test twenty subjects performing a three-minute computer task, consisting of both typing and mouse activities, with three chair seat conditions (inclination of −14°, 0° or dynamic) and three types of arm support (none, chair, table). The angle between the seat pan and the back support was fixed, where the angle of the back support relative to the seat pan was consistent at a 93 angle. The nine resulting conditions were tested using a randomized balanced design with a 5-min familiarization period prior to the experiment and a 10-min break half-way through the measurements.Unilateral surface electromyography (EMG) was recorded from nine upper neck and shoulder muscles at the right side. Exposure variation analysis (EVA) using normalized EMG was performed to analyse load and characteristics of muscle activity in both the amplitude and time domain. Prior to the experiment, maximal voluntary contractions (MVC) and standard isometric contractions (SIC) were recorded.A mixed design repeated measures analysis of variance (ANOVA) was performed with chair inclination (−14, 0, dynamic) and arm support (with, without, table) as within subject variables and typing skill (touch-typing vs. non-touch-typing) as between subject variable.Results. A chair inclination of −14° resulted in lower muscle activity with higher variation in muscle activity for the trapezius ascendens and transversus muscles, whereas higher muscle activity with higher variation in activity was found for the other shoulder muscles.Significant main effects of arm support on muscle activity were found for several muscles. Muscle activity significantly was lower in the table support condition compared to the without support condition. For several muscles, the table support condition resulted in a significantly lower muscle activity compared to the chair support condition.No differences in muscle activity were found between touch-typists and non-touch typists. %MVC, APDF were similar for all chair inclination and support conditions for all muscles. Touch-typists were more productive.Conclusions. It is concluded that: (1) A backward chair inclination of −14°, as recommended in the literature, decreases the muscle activity of the muscles depressing and retracting the shoulder, whereas activity of the muscles elevating the arm and shoulder increases. The variation in overall shoulder muscle activity increases with a backward chair inclination; (2) The use of arm support or the use of the table as an arm support resulted in lower and more dynamic muscle activity; (3) No differences in muscle activity were found between touch-typists and non-touch-typists, but touch-typists were more productive.

Erwin M. Speklé, Bas H. M. van der Doelen, Jaap H. van Dieën

Implementation of the Ergonomic Principles: In the Regulations and at the Workplace

IEA 2018 Symposium: Comparison of Ergonomic Rules Between Countries

The paper present the ergonomic principles spread in the French speaking countries by the «activity ergonomics» based on the Ergonomic Work Analysis which develops a “bottom up” problem building approach.The different places where the traces of the ergonomics principles implementation in France are identified: legislations, collective agreements… In the French Labour Code are located the regulations, passed from the 70’s to the 90’s, issued mainly from the European directives transposition, which provides for to adapt the work to human. Such requirements constitute what the jurisprudence has defined as a so called “result obligation” in the field of OHS.These principles are only partly implemented in the real world. And with the recent transformations in the work, such as the development of an economy based on services, marked by digitalization, artificial intelligence, robotization, uberization, one states that the work situations produce new risks, In front of new stakes, the issue of the principles updating is posed and the answers given recently in the laws are questioned.

Pascal Etienne

Neck Disorder Influenced by Occupational Reward Type: Results from Effort-Reward Imbalance Model Based on IPWS

Effort-Reward Imbalance model is known as one of the survey method of occupational stress and also as an effective element on health condition according to its parameters. Due to types of rewards generally, and reward subscales in this model specifically, each one can have a distinctive effect on health perception, current study is aimed at determination of the most effective reward subscale for managing work-related neck disorder in industries.All of workers who participated in IPWS study (N = 1126), were entered in the statistical analysis stage. After completing personal and organizational information, they responded to Van Vegchel et al. Effort-Reward Imbalance and also Dutch questionnaires for their musculoskeletal disorders. Chi-square and t-test comparisons were performed and the final regression model was presented with a significance level of 0.05.The mean (Standard deviation) age of workers and musculoskeletal disorders prevalence in neck were 33.21 (7.63) years and 34 percent respectively. Also in workers with neck pain, odds ratio between effort and monetary reward, between effort and respect reward, and between effort and security reward in their jobs were 1.35, 2.07 and 1.32 respectively. After elimination of confounders in final regression model, significant correlation was remained only between effort and job respect reward.According to high prevalence of musculoskeletal disorders in neck and also large amount of effort-reward imbalance in Iranian workers, implementing interventions are recommended. Based on results of present study, it is suggested that main intervention must be focused on respect and esteem reward in jobs.

Seyed Abolfazl Zakerian, Saharnaz Nedjat, Saeedeh Mosaferchi, Hadi Ahsani, Fateme Dehghani, Mahdi Sepidarkish, Alireza Mortezapour Soufiani

Ergonomics Risk Factors Prevailing in Kota Doria Loom Weavers of India

Weaving of Kota Doria fabric has been a traditional activity of Ansari community of the Kota region. After abandoning this art by men in order to reach more stable and money yielding means of livelihood, women of the community have adopted this traditional activity in order to continue their culture and generate least minimum income. Weaving of Kota Doria fabric is carried on pit loom. 100 women weavers from Kaithoon area of Kota district participated in the study. In depth observation of the workplace followed by the subjective assessment of body discomfort and Workplace Ergonomic Risk Assessment (WERA) method was carried out. On analysis of WERA, the leg score for WERA body part was >4 in 73% of weavers whereas discomfort in knees and legs were reported by 87% yielding a significant association between WERA body part score and self-reported pain (χ2 = 20.51; p = 0.000). The body part score for shoulder region during Kota Doria operation yielded a score of >4 in 68% and cause pain in 72% association being significant (χ2 = 23.86; p = 0.000). The neck region for WERA body part score was >4 in 80% of the weavers with 89% reporting pain or neck discomfort with significant association (χ2 = 5.96; p = 0.014). the back region score for WERA body part was >4 in 79% of weavers whilst discomfort reported by 97% with a significant association (χ2 = 4.20; p = 0.040).Therefore it can be concluded that existing Kota Doria pit loom weavers depict significant prevalence of MSDs and need intervention for enhancing productivity and occupational wellbeing of the weavers.

Nabila Rehman

Effect of a Passive Exoskeleton on Muscle Activity and Posture During Order Picking

Order picking is a standard task in logistics that is difficult to fully automate due to the variety of products. A passive exoskeleton can therefore be a strategy to support the order picker. This field study investigated the effect on muscle activity and posture of the back and shoulders.Ten operators performed the task of order picking cheese in real life conditions 1,5 h without and 1,5 h with exoskeleton. The electromyography (EMG) of m. Erector Spinae and m. Trapezius pars descendens was measured. The posture of the back and upper arms were recorded by motion sensors. The subjective experience was questioned on a 5 point scale.During order picking the back muscle activity was 9 and 12% lower when wearing the exoskeleton, respectively for the left and right side. The back was bent more than 30° for 26% of the time with exoskeleton and 23% without. The difference was not significant. The muscle activity and postures in the right and left shoulder also didn’t show meaningful differences. Subjectively the physical load was experienced positively with the exoskeleton. However, fatigue and safety require some attention.The practical implication of an exoskeleton in the prevention of low back pain is discussed. Due to the rather small benefit this will probably not be the only solution to reduce the physical load of a job.

R. Motmans, T. Debaets, S. Chrispeels

Simulation Study on the Effects of Adaptive Time for Assist Considering Release of Isometric Force During Elbow Flexion

The increasing trend of development of assistive technology allows for the use of assistive robots such as power assist devices to be prevalent in various social domains. Such power assist devices usually provide incidental power to their users, requiring human-machine force interaction. If the power assist device requires users to release their muscular force without considering adaptive time, users might be confused to control the level of their manual performance in response to the external force. This study investigated adaptive time with varying release rates of isometric force during one-arm elbow flexion, focusing on muscle activity and force control. Eight participants conducted graphical force-tracking tasks designed to simulate power-assist condition. Electromyography signals and the tension forces of the biceps brachii and triceps brachii were measured. The results implied that sufficient adaptive time for muscular force release induced better performance level with a smaller difference between the target force and the actual force. However, higher subjective exertion was also accompanied during the longer time for muscular force release. This study suggests that in designing power assist devices, the duration for muscular force release and consequent characteristics should be considered to maintain the precise level of force control.

Jeewon Choi, Ping Yeap Loh, Satoshi Muraki

Reducing Musculoskeletal Pains of Operating Theatre Nurses

Musculoskeletal pains top the list of the most common work-related ailments in Austria. In 2016, they were the second-leading cause for taking sick leave. The Austrian Employee Protection Strategy for 2013–2020 aims to reduce work-related health risks. The first goal of the presented monocentric, randomised, con-trolled study was to survey the intensity and regional distribution of musculoskeletal pain of operating theatre nurses. Secondly, it was to investigate the effectiveness of a combined programme consisting of awareness training and an exercise programme for reducing pain. The intervention group received a two-stage intervention, and the control group received no intervention. The first stage of the intervention was an awareness training. The second stage was a specific corrective exercise. The musculoskeletal pain was recorded with a modified version of the Nordic questionnaire at three different times. Fifty-six individuals took part in the programme. The two most common pain areas reported by all respondents were the shoulder and neck region with an average pain level of 5.62 (SD = 3.03) and the lumbar region of the spine with an average pain level of 5.54 (SD = 3.14). The awareness training led to a 4% (1.1 points) increase in the reported pain level across all pain areas compared with the control group. The pain relief programme led to a 16% (4.9 points) decrease in pain levels across all pain areas. In conclusion, a programme based on awareness training and corrective exercises can increase awareness of pain during the occupational activities of operating theatre nurses.

Peter Hoppe, Karl Schableger, Brigitte König, Brigitte Eichinger, Anna Gabriel, Tanja Holzmann, Iris Frenner

Is the Work Safe? Do I Feel Safe? A ‘Choose Your Own’ Psychosocial Adventure

Physical and psychosocial demands are known to affect the development of musculoskeletal disorders (MSD). Psychosocial factors are also known to affect the length of time for employees to return back to work after a work-related injury. Internationally, despite the vast body of research and multitudes of different approaches in this area over the last 2–3 decades, many employers report that they are unsure what psychosocial factors are or what to do prevent injury or to enable easier and quicker return to work. In light of this challenge, WorkSafe Victoria, Victoria’s occupational health and safety regulator, has developed a simple and interactive visual engagement concept to support the publication of work-related stress guidance material and manual handling guidance material. It is designed to show employers what psychosocial factors are, and the role they play in the development of injury and how they can affect an employee returning to work after injury. The concept includes how the Victorian occupational health and safety legislation applies and how discharging of health and safety duties can impact both positively and negatively on injury, wellbeing, workplace safety culture, business productivity and life at home and in the greater community. More importantly, the visual concept can provide a talking point for what good interventions can look like for organisational psychosocial factors. Be part of the ‘choose your own’ adventure during the poster presentation “Is the work safe? Do I feel safe?” and see creativity in practice from WorkSafe Victoria.

Alison Gembarovski, Ian Sutcliffe, Lachlan Hislop

ERIN: A Practical Tool for Assessing Exposure to Risks Factors for Work-Related Musculoskeletal Disorders

The prevention of work-related musculoskeletal disorders (WMSDs) has become one of the greatest of daily challenges that faces ergonomics professionals. One of the actions carried out as part of prevention is the assessment of exposure to WMSDs factors. To date, many different ergonomic assessment methods have been developed. However, in many cases, the correct use of these methods is conditioned by having personnel with high training and experience in ergonomics, which is scarce, mainly in Latin American countries, where there is a presumption of a greater presence of WMSDs risk factors. For this reason, a necessity of having practical methods to evaluate a wide variety of tasks and generate improvement actions has been identified and stated in these countries. In this paper, Evaluación del Riesgo Individual (Individual Risk Assessment) (ERIN) method is presented, which can be used by non-expert personnel in the ergonomic assessment of tasks. ERIN has proven to be easy to learn, easy to use, requires little training time and is a useful tool in identifying opportunities for ergonomic improvement. Finally, a case study showing how to evaluate a task with the ERIN method is included and some results of studies carried out to evaluate the reliability, validity and usability of the method are mentioned.

Yordán Rodríguez Ruíz

A Study on Posture Analysis of Assembly Line Workers in a Manufacturing Industry

Objective: In order to reveal and analyze the feature of surface electromyography (sEMG) signal and assembler’s posture of repetitive work, assembler’s posture and electrical manifestations of localized muscles was collected by using the inertial motion capture technology and sEMG during the work. Methods: Six male workers were chosen in laser lettering workshop of a medical equipment manufacturing industry. They performed repetitive pull-and-push operation, meanwhile, sEMG and posture signal in 10 min period was collected at the beginning and end of work. Results: The MFs of LST, LBB and LFCR were significantly lower at the beginning than at the end of work, while the RMSs of LST, LBB and LFCR were significantly higher at the beginning than at the end of work. And the differences of LST between the beginning and the end of work was most distinct. Keeping fixed joint angle for a long time had a greater effect on muscle fatigue, and the result was statistically significant (P < 0.05). Conclusions: The fatigue strength of muscle increased significantly with repetitive push-and-pull operation of workers for a long time, especially of the shoulder; And fatigue was easily caused by keeping fixed joint angle for a long time.

Jingyun Li, Yabo Lu, Yajun Nan, Lihua He, Xin Wang, Dongsheng Niu

Introduction and Testing of a Passive Exoskeleton in an Industrial Working Environment

Background: Commercial availability of passive exoskeletons, based on the use of springs and durable in an industrial setting, made the these devices much more accessible. However, there is limited evidence of the effect of these devices on physiological aspects, factors outside the single-task regulated laboratory environment and, discomfort and acceptance by the employee. Objective: This study aimed at evaluating the effect of a passive exoskeleton on muscle activity, kinematics and acceptance by employees on multi-task workstations on the shop floor. Methodology: Starting with an individual instruction course, nine participants were encouraged to test the device (Laevo, V2.4) during three weeks. After this period, motion and surface EMG were measured during two consecutive periods of executing daily tasks for at least 30 min (with exoskeleton and without exoskeleton). Results: Results show that RMS values were significantly higher for the Trapezius muscle with the exoskeleton (Mdn = 44.02) compared to the measuring period without the device (Mdn = 34.83, T = 0, p < 0.05, r = −.73); No differences were found for Erector Spinae and Biceps Femoris muscle activity. Participants reported significantly higher discomfort scores for the upper back/chest and thigh region with the exoskeleton (both p < 0.05, r = −.68). Conclusion: Results show high discomfort scores and no difference in lower back muscle activity possibly as a result of an inadequate amount of resistance given by the exoskeleton while bending over.

Steven Amandels, Hans Op het Eyndt, Liesbeth Daenen, Veerle Hermans

Ergonomics Introduction and Management of Risk to Biomechanical Overload in a Mechanical Engineering Factory Production Chain Saws and Trimmers

The biomechanical overload risk, especially in the upper limbs and the spine, resulting in Italy one of the most significant security issues for manufacturing companies due to possible occupational diseases to which it may be related.Already for several years the most careful companies consider necessary proper management of this risk which involves all corporate entities and which, following an adequate risk assessment, addresses the main variables that determine a concrete exposure by the employees. As the risk is multifactorial, only with the involvement of all the factory entities, a gradual reduction in exposure conditions is possible.The management process started in 2014 by EMAK SPA, the leading manufacturer of industrial tools for greening and gardening, initially saw the involvement of the Factory Production and Process Engineering in a thorough training and operational process.This produced in 2015 a specific procedure defined “of policy and guidelines” for the design of workstations with ergonomic features, suitable for the entire working population, even in view of its gradual aging.In the following years, training was given to workers on specific biomechanical overload risk that included behavioral routes to avoid extreme exposure conditions.In 2016, the Company’s Management strongly wanted department of industrial design to be part of the project, by also proposing changes in the design of the models sold, that would improve the working conditions of the assembly lines.Finally, in 2017, the involvement of the Medical Worker was concretized, which together with the company’s workgroup identifies the critical conditions still present in every position of the company to include not only workers with normal characteristics, but above all, workers with reduced capacity working or advanced age.Over the years, EMAK’s “Ergonomics Project” has allowed to improve workplaces and reintroduce about 50% of workers with restrictions.

Marco Placci

MSDs: Recommendations for Prevention, Rehabilitation and Occupational Reinsertion – Results from a Survey by the Ergonomics Working Group of the ISSA Health Services Section

For most countries, musculoskeletal disorders (MSDs) are still a major occupational health concern. It is therefore in everyone’s interest to have effective prevention and rehabilitation practices.In order to compare the approaches of different countries for the prevention of work-related musculoskeletal disorders as well as the rehabilitation and reinsertion of workers with MSDs, the Ergonomics Working Group of the Health Services Section of the International Social Security Association has decided to carry out a questionnaire-based survey.This questionnaire has been addressed to stakeholders that, directly or indirectly, are faced with the issue of work-related MSDs: accident insurance bodies, rehabilitation centres and their therapists, occupational physicians, human resource departments, professional organisations, trade unions, companies, etc.The results have been analysed, they show a great disparity of modes of action both in prevention and rehabilitation. The Ergonomics Working Group of the ISSA Health Services Section will provide its conclusions and recommendations to advance the return to employment and job retention for these pathologies, which predominate in all countries.

Jean-Pierre Zana, Sigfried Sandner, Barbara Beate Beck, Martine Bloch, Stefan Kuhn, Irène Kunz-Vondracek

The Biomechanical Overload of the Rachis in Push and Pull Activities: Historical Revision, State of the Art and Future Prospects in the Light of the New High-Sampling Digital Dynamometers and the Multitask Features of Work in the Workplace

The risk of biomechanical overload for the rachis is characterized by two different exposure situations: lifting of loads and push and pull of carts or objects. If in the first case the risk is determined by the continuous and repeated compression of the intervertebral disks, in the second case the damage is generated differently by lateral-lateral and anteroposterior cutting forces acting on the disk.

The study of the risk caused by Towing and Driving activities was based on three main areas: epidemiological studies, psychophysical studies and physiological studies developed mainly since the 1970s and continued until today.

The most concrete reference to these investigations is, however, the famous study that uses the psychophysical approach conducted in the Liberty Mutual Research labs for more than 25 years, synthesized in 1991 by Snook and Ciriello and integrated by Mital et al. (1993).

Substantially, the psycho-physical study of Snook and Ciriello that generated the resulting tables is performed to determine how risk factors can influence the maximum acceptable forces during a working day. The problem with these studies is the correct identification by the operator of its real tolerance limit, and the absence of evidence of direct correlation with health disorders during work.

Keeping these references today, through sophisticated instruments, but with good price, is possible to obtain a significant amount of relevant information from the measurements that describes in a much deeper way the working conditions.

Last but not least, it is necessary to expand the calculation of the risk index in push and pull activities which must adequately describe the different working conditions that occur on the working day.

A proposal consistent with the formula N.I.O.S.H. of multiple tasks defines a computational scenario similar to the multitask, proposed by Waters Thomas, Putz-Anderson v. Garg A., End LJ, in the ergonomics publication “Revised niosh equation for the design and evaluation for manual lifting tasks”, 37, 7, 1993 pp. 749–776.

Calculation proposals should, however, be able to reflect actual worker exposure in push and pull multitask activities but may not yield results different from the values used so far in the Snook and Ciriello tables. For this reason, hundreds of work-related measures have been performed to compare historical values with those derived from new measurement modes

Marco Placci, Marco Cerbai, Leonardo Bonci

Recent Changes to the Manual Handling Law and Implementation in Chile

The Law No. 20.944 that modifies the Chilean Work Code in regulating the maximum human load weight was published in 2016. This Law replaced the No. 20.001 Law (2005) and reduced from 50 kilos to 25 kilos the maximum limit of manual handling of load for adult male population and maintained the maximum limits of 20 kg for both men and women under 18 years. It prohibits these tasks for pregnant women and indicates that the maximum limit will be modified to the extent that other aggravating factors exist, in which case, the manipulation must be carried out in accordance with the guidelines established in the Technical Guide. This guide, developed for the first time according to Law No. 20.001, had to be reviewed and updated was carried out by a team of Chilean ergonomists and it was published on March 1, 2018. This article is a brief analysis and a reflection of the components involved in the process of creating a technical guide to be used in the country, which not only includes technical aspects regarding the tools for its application, also involves considering other aspects such as political and context management, to ensure that the regulation is effective and widely applied.

Paulina Hernández Albrecht

Update on the Musculoskeletal Health of Office Employees in Hong Kong

Employers have legal responsibilities to protect their employees’ health and safety at work. The Occupational Safety and Health (Display Screen Equipment) Regulation (Cap 509B) was enacted in Hong Kong in 2003 which aims at protecting the health and safety of employees who use computer for prolonged period of time. The study result showed that from 2015 to 2017, 96% of 1,618 employees spent at least six hours a day in computing work. The number of employees spending prolonged hours on computers was the highest compared to previous studies. With regard to the musculoskeletal health for the period in 2015 to 2017, 74% of sample employees reported musculoskeletal symptoms for at least one body region. The top three most commonly reported body region with discomfort, in 2015 to 2017, was Shoulder (69%), Neck (49%) and Lower Back (39%). Shoulder, Neck and Lower Back have been the highest reported regions experiencing discomfort since 2011 in Hong Kong. For the seeking of medical treatment, from 2015 to 2017, 39% of sample employees reported that medical treatment was needed for treating their musculoskeletal symptoms. A similar percentage of 42% of sample employees reported requiring medical treatment from 2013 to 2014. The high number of reported cases requiring medical treatment represents the high medical cost borne by employers. In conclusion, the reported rate of musculoskeletal discomfort among office employees has been high in the past 10 years. Regular analysis and updating of the musculoskeletal health of office employees in Hong Kong is needed.

M. Y. Chim Justine

Risk Assessment in an Industrial Hospital Laundry

Background. The laundries present in hospitals are responsible for washing, disinfection and distribution of working clothes. In healthcare services, workers from laundry services are exposed to various occupational hazards, including the ergonomic ones, related in particular to repeated movements of lumbar flexion, raising the arms above shoulder level and transportation of loads. These conditions can provoke musculoskeletal disorders (MSD), one of the most common occupational disease present in developed countries.Methods. Step one: evaluation of the baseline condition by two different approaches. (1) Risk assessment with the study of working conditions using a specific integrated tool; (2) analysis of referred symptoms from workers using a specific validated questionnaire for MSD, the Nordic Musculoskeletal Questionnaire. 167 workers are included, 51 males (age 42,8 ± 10,3 years), 118 females (age 45,1 ± 8,8 years). Step two: changes of working organization on the basis of the results of step one.Results. The analysis of questionnaires showed higher prevalence of symptoms in the female groups, in particular in the iron area. Symptoms increase with age and BMI but not with years of employment. On these basis a reorganization of the job processes were carried out, with changing in the machinery and in job organization (e.g., time of work at the workstation, including more frequent rotations of workers), and a specific individual practical training of workers was realized.Discussion. The incidence of MSD symptoms appear very high. The inherent characteristics of the job associated with individual factors and unfavorable ergonomic conditions can contribute in the occurrence of MSD, injuries and aggravation of existing diseases.

Giulio Arcangeli, Manfredi Montalti, Francesco Sderci, Gabriele Giorgi, Nicola Mucci

Job Seniority and Time of Daily Exposure to Biomechanical Risk Factors in Claims of Work-Related Upper Limb Musculoskeletal Disorders in Chile

Since March 2016 in Chile, the Workplace Assessment Tool (WAT) has been used in order to provide the professional disease qualification process with elements that ensure greater objectivity. Six WAT formats were developed according to upper limb segment or pathology: shoulder, elbow, wrist, carpal tunnel syndrome (CTS), thumb and fingers. This tool collects information about the worker, seniority and time of exposure to risks during the workday. At the international level, no consensus has been reached regarding the development times of work-related musculoskeletal disorders. The objective of this study was to estimate the relationship between seniority, daily exposure during working hours and biomechanical risk factors. Daily exposure presented an average of 435 min (SD = 84), without significant differences when analyzing according to the segment evaluated. Seniority presented significant values for the Wrist and CTS segment (X2 = 59.25, df = 25, P = 0.00). In addition, for the Wrist segment, a positive difference was generated in the range of less than 6 months old, in the presence of two risk factors (X2 = 36.314, df = 15, P = 0.002). It is concluded that there is a relationship between seniority and the pathologies that affect the wrist segment, however this relationship with the rest of the segments is not fulfilled, with the exposure time in the day nor with the biomechanical risk factors.

Marta Martínez, Paulina Hernández

The SIN-DME Questionnaire (Symptoms of INcomfort Associated with Muscle Skeletal Disorders)

This research was carried out between 2010 and 2017; the objective was to develop the Intervention Protocol for the Prevention of Musculoskeletal Disorders, the research followed three phases as follows: the first one dealt with the design of the protocol and the analysis tools, the second one focused on the adjustment of the intervention and modeling processes of the tools and the third one on the validation of the protocol and its operation in the companies. In total, the applications of the tools and the validation of the development were carried out with the results obtained from 97 companies from 11 economic sectors that participated; from this universe of companies a sample of 2648 workers was constituted. This is a self-assessment questionnaire of WMSD’s-related symptoms, designed in the category of questionnaires that focus on identification through the perception of health by individuals.In this regard, it should be noted that previous studies carried out by the scientific team of the ergonomics laboratory of the University of Rosario, started from the hypothesis that groups of workers with some pathology associated with WMSD’s would present a low perception of health, however, it was found that most of the workers perceived their own state of health as excellent. This is explained because when the symptomatology of the pathology presented by the worker does not prevent or condition the activities of daily life, people will perceive that they have an adequate state of health [1]. The questionnaire uses validated information, scales and the development of visual identification items to bring the representations of individuals closer to the estimates made. The conceptual objective for the development of the questionnaire is to record and measure the prevalence of symptoms in workers who may be associated with a musculoskeletal disorder, with the purpose of verifying the presence of symptoms later through a more exhaustive evaluation of health conditions.

Juan A. Castillo-M, María C. Trillos Ch

Issues with the Implementation of Material Handling Regulations in Switzerland

In Switzerland, there are specific legal requirements for companies to provide lifting tools and organisational measures to avoid the necessity to lift. From international surveys on risks and at work and company prevention measures it does seem that these requirements are having an effect, however, in order for laws to be implemented, companies must be aware of the requirements and labour inspectors must insist on compliance. In both of these areas, there is still work to be done. The survey show that physical risks at work are generally increasing, although they still remain within the European average. Companies seem to have introduced the technical measures more frequently than the organizational measures prescribed by the law.

Maggie Graf

Theoretical Impact of Workplace-Based Primary Prevention of Lumbar Disc Surgery in a French Region: A Pilot Study

Aim: To assess the theoretical impact of workplace-based primary interventions designed to reduce exposure to personal and/or work-related risk factors for LDS. Methods: Cases of LDS were assessed using hospital discharge records for persons aged 20–64 in 2007–8 in the French Pays de la Loire region. We estimated the number of work-related cases of LDS (WR-LDS) in high-risk industry sectors. Three theoretical scenarios of workplace-based primary prevention for sectors at risk have been simulated: a mono-component work-centered intervention reducing the incidence of WR-LDS by 10% (10%-WI), and two multicomponent global interventions reducing the incidence of all cases of LDS by 5% (5%-GI) and 10% (10%-GI) by targeting personal and occupational risk factors. Results: Four industry sectors were at high risk of LDS in the region, amounting to 435 [351–532] LDS cases, of which 152 [68–253] were WR-LDS: construction and information & communication for men; wholesale & retail trade and accommodation & food service activities for women. AFE was limited for each industry sector, 30%, 50%, 33% and 55%, respectively. The 10%-WI, 5%-GI and 10%-GI scenarios hypothetically prevented 15 [7–25], 22 [18–27] and 44 [35–53] LDS cases among sectors at risk, respectively. Discussion: Prevention scenarios combining actions on personal and occupational risk factors would be the most effective, compared to prevention focused only on occupational risk factors. This suggests that, to reduce the incidence of LDS, implementing actions of promotion of health at work would be necessary in addition of actions on occupational risks.

N. Fouquet, A. Petit, A. Descatha, Y. Roquelaure

Matching New Ergonomics Regulations to Stakeholder Competence in South Africa

In 2013 the South African department of labor convened a new technical committee to develop ergonomics regulations for the country and in 2016 a draft of the regulation was released for public comment. Although the existing occupational health and safety act refers to ergonomics, the new regulations would be the first to emphasize the requirement for South African employers to have an established ergonomics program. In order to further contextualize these regulations, it is important to understand several key factors relating to each of the four identified stakeholder groups (business, government, labor and specialists) identified in the regulations. Firstly, the nature of business ownership in the country. The small and medium size enterprise sector contributes approximately 36% of the gross domestic product and constitutes up to 90% of formal businesses, while the informal economy contributes a further 8% of gross domestic product. These sectors typically function under several constraints and whether these sectors have the finances and resources required to effectively implement the regulations is questionable. Secondly, it is necessary to ensure that the department of labor and their inspectors are in a position to not only implement the regulations but also to assist the various sectors of the economy in the development of their programs. Currently, only a small proportion of the inspectorate have any formal training and the necessary skills in ergonomics. Thirdly, from a labor perspective the level of knowledge and training of the workers and those likely to be responsible for the actual implementation and running of the ergonomics program needs very careful consideration and better understanding. Lastly, due to the fact that the number of ergonomics practitioners (at all levels) and training programs in South Africa are small there is a very real risk that they are inadequately resourced to deal with the increased demand associated the regulations being introduced. It is clear that within each group of stakeholders there are legitimate barriers to the effective implementation of the regulations. In order to overcome these barriers, it is imperative that the level of competence of each stakeholder is matched to the demands placed on them by the new regulations. This presentation will highlight the ways in which the stakeholders have gone about trying to address the issues of ensuring their competence to deal with the introduction of the new ergonomics regulations. It will further explore some of the challenges that remain to be overcome and question whether or not the system (and the various stakeholders) are currently mature enough to cope with the introduction of broad and wide ranging ergonomics regulations.

Andrew Ivan Todd

Utility Analysis of the Application of the Variable Lifting Index (VLI)

Introduction: The Variable Lifting Index (VLI) is one of the proposal extensions for the application of the Revised NIOSH lifting equation (RNLE) in highly variable work conditions. But is it necessary to apply these complex mathematical models to identify the main risk factor to be improved? Methods: 10 warehouse clerk workplaces from different companies of logistics sectors have been assessed using VLI. 118 OHS practitioners have been asked about the strategy usually used to assess the manual lifting risk. After applying these strategies to the analyzed workplaces, the potential to identify efficient risk reduction interventions is compared.Result: The most frequently used strategy to assess the manual lifting risk in highly variable conditions is to analyze the most frequent posture with the average weight. This strategy has identified the most significant risk factor, as VLI identified it, only in 2 out of 10 cases analyzed.Discussion: VLI permits to identify the most efficient intervention to reduce the exposure level in a complex and variable working conditions. The use of other strategies will identify insufficient or misleading interventions. From a practical point of view, VLI will contribute to manage occupational risk related to manual lifting loads in a more efficient manner.

E. Alvarez-Casado

Postural Deviation Gestures Distinguish Perceived Pain and Fatigue Particularly in Frontal Plane

Office workers frequently report discomfort in the neck, back and shoulders. Extreme and prolonged static postures are known risk factors. Sit-stand workstations encourage regular postural changes and tend to reduce discomfort. Head and upper back deviations were recorded for ten adults entering data using a seated desk and two sit-stand desks following three twenty-minute cycles with 6 or 9 min standing. Participants reported their perceived back pain, neck pain and fatigue following each recording. Postural deviation was discretized into levels in sagittal and frontal planes. Series of four consecutive postural levels, termed ‘Postural gestures’, were tracked for each plane, workstation, and participant. Averages by quintile for perception values of each feature revealed inflection between low (“absent” or “No”) and high (“present” or “Yes”) slopes. Postural gestures were ‘important’ when associated with perceived variations. Significance occurred with contingency calculations pairing different postural gesture occurrence relative to (perception) “absent” and “present” quintiles.Some postural gestures occurred more when perception was “absent” than “present”, and vice versa. These differences may indicate postural behavior that increases risk or protects from pain or fatigue. All of the 81 postural gestures that occurred for all ten participants only occurred when using sit-stand workstations. Eighty-three percent (83%) of those occurred in the frontal plane with similar numbers for neck pain, back pain and fatigue. More patterns occurred for absent than present perceptions.Matching postural deviation patterns with present and absent perceived back and neck pain, and fatigue distinguish between groups, complementing known Musculoskeletal Disorder (MSD) contributors.

Nancy Black, Andrew Hamilton-Wright, Joshua Lange, Clément Bouet, Mariah Martin Shein, Marthe Samson, Maxime Lecanelier

Identifying Situational Operational Leeway for Subcontract Supervisors so as to Progress in MSD Prevention

Supervisors seek to regulate critical situations influencing operators’ capacity to deal with risks of musculoskeletal disorders (MSD). The regulation adopted depends on the supervisors’ situational operational leeway (SOL), which is influenced by their individual characteristics and by characteristics related to their working environment (2–3). The aim of this study was to identify the components of SOL for first-line supervisors working through subcontracting, in order to allow them to contribute to the design of a working environment favourable to prevention of MSDs in the supervised operatives. Two qualitative case studies were conducted on meat-cutting supervisors employed by an external company (EC) and working in a user company (UC). From interviews with the supervisors and observation of their work (for 2 to 6 h on 4 days each), 15 critical situations were identified. These situations were then examined through self-confrontation interviews. The components of the SOL for the two supervisors were then constructed from the analysis of those situations. The SOL of the subcontracted supervisors breaks down as 16 components: 4 individual ones (i.e., the supervisors’ cutting skills), 4 organizational ones related to the EC (i.e., procedural autonomy), 4 organizational ones related to the UC (i.e., flexibility of the production modes), and 4 collective components related to opportunities to cope collectively by interacting with EC-supervised operatives and/or with UC employees (i.e., with support from UC supervisors). Individual components were mobilized most often, whereas organizational components were not systematically identified. The collective components were mobilized particularly in situations lacking organizational components.

A. Cuny-Guerrier, S. Caroly, F. Coutarel, A. Aublet-Cuvelier

Work-Related Upper Extremity Musculoskeletal Disorders and Low Back Pain in Japan

In Japan, compensable occupational diseases are officially listed in Appended Tables 1 and 2 of Ordinance for Enforcement of the Labor Standards Act. The category No. 3 (diseases caused by work with extreme physical tension) includes subcategories of (b): Low back pain due to work to handle heavy objects, those done in unnatural postures or others which involve excessive tension to low back, and (d): musculoskeletal disorders of the back of the head, neck, shoulder girdle, upper arm, forearm, or fingers due to work which require repeated input into a computer or other operation involving excessive tension on the upper limbs. Local labour standard bureau is in charge of judging the work-relatedness.The detailed criterion for upper extremity disorders was first published as a notice from the Labour Standard Bureau, Ministry of Labour on Feb 5, 1975, as “Judgment criterion for work-relatedness of upper extremity disorders from keypunching work” (Notification No. 59, 1975) and revised on Feb 3, 1997, as “Judgment criterion for work-relatedness of diseases from upper extremity work” (Notification No. 65, 1997).The detailed criterion for low back pain was published as “Certification criteria of occupational low back pain” (Notification No. 750, 1976).In this paper, minimum exposure criteria for upper extremity musculoskeletal disorders and low back pain is described from the view point of the certification criteria for compensable occupational diseases in Japan.

Hiroyuki Izumi, Seichi Horie

Smart Work Clothes Give Better Health - Through Improved Work Technique, Work Organization and Production Technology

Musculoskeletal disorders (MSDs) constitute a major health problem for employees, and the economic consequences are substantial for the individuals, companies and the society. The ageing population creates a need for jobs to be sustainable so that employees can stay healthy and work longer. Prevention of MSD risks therefore needs to become more efficient, and more effective tools are thus needed for risk management. The use of smart work clothes is a way to automate data collection instead of manual observation. The aim of this paper is to describe a new smart work clothes system that is under development, and to discuss future opportunities using new and smart technology for prevention of work injuries.The system consists of a garment with textile sensors woven into the fabric for sensing heart rate and breathing. Tight and elastic first layer work wear is the basis for these sensors, and there are also pockets for inertial measurement units in order to measure movements and postures. The measurement data are sent wireless to a tablet or a mobile telephone for analysis. Several employees can be followed for a representative time period in order to assess a particular job and its workplace. Secondly, the system may be used for individuals to practice their work technique. The system also gives relevant information to a coach who can give feedback to the employees of how to improve their work technique. Thirdly, the data analysis may also give information to production engineers and managers regarding the risks. The information will support decisions on the type of actions needed, the body parts that are critical and the emergency of taking action.

Jörgen Eklund, Mikael Forsman

AUVAfit

AUVA Strategy for the Prevention of Musculoskeletal Disorders

“Work should not make us sick – work can make us fit”, to bring this slogan to life, it is important to consider some principles and to constantly optimize work and workplaces. Presently, musculoskeletal disorders (MSDs) cause nearly a quarter of the overall days of sick leave in Austria. According to EU-OSHA (European Agency for Safety and Health), MSDs are one of the most common work-related diseases. Throughout Europe, they affect millions of workers and cost employers billions of euros. Tackling MSDs helps to improve the health related quality of workers life, reduces cost for the employers thus making sense also in an economic way. To minimize work-related risk factors the Austrian Workers’ Compensation Board (AUVA) designed a program called “AUVAfit”. The aim of this program is to improve the workplace environment by reducing physical and mental risk factors. AUVAfit is available for the modules “Ergonomics” and/or “Occupational Psychology”. The AUVAfit ergonomics team – in cooperation with the company – works out measurements to improve the work places according to ergonomic guidelines.

Julia Lebersorg-Likar

Musculoskeletal Disorders Among Occupational Drivers Caused by Whole Body Vibration and Awkward Posture

Musculoskeletal disorders (MSD) can be caused by multifactorial workloads such as whole-body vibration (WBV), awkward posture and heavy lifting. Due to the complexity of field measurements, there is so far no epidemiological study investigating posture quantitatively. Therefore, we investigate the association between MSD outcomes and these exposures among 102 professional drivers by field measurements. At different workplaces the combined exposures of WBV and posture were measured for 58 professional drivers. These measured data were extrapolated for subjects with the same workplaces and job tasks. The CUELA measuring system was used to capture and analyse the exposure of the posture. Further, the percentage of time spent in a non-neutral angular range was used to describe the upper body posture. Health and personal data as well as information about psychosocial factors and lifting tasks were collected by a questionnaire.While an index for non-neutral posture shows significant association with the most MSD outcomes, daily vibration exposure value only effects lumbar spine disorder significantly. Also in case of sick leave, lifting and awkward posture appear to be more strongly associating than WBV exposure.

Nastaran Raffler, Jörg Rissler, Rolf Ellegast, Thomas Kraus, Elke Ochsmann

RAMP – A Comprehensive MSD Risk Management Tool

The objective of this paper is to describe the development, dissemination and preliminary effects of the use of a new musculoskeletal disorder (MSD) risk management tool for manual handling, RAMP (Risk Assessment and Management tool for manual handling Proactively). RAMP is research based and developed in close collaboration between researchers and practitioners with a participative iterative methodology. A broad strategy is used for the dissemination, including the use of professional networks, conferences, a specially developed homepage, and Massive Open Online Courses which also provide training on the tool use. The tool has been spread widely to about 45 countries since the release 2017. E.g. Scania CV uses RAMP as its global standard method for managing MSD risks at logistics and machining departments. Among the preliminary effects results show that at one department risk reduction measures had been taken for more than 2/3 of the work stations with assessments signalling elevated risk levels after 1.5 years. Further studies on RAMP are discussed. It is concluded that the development and the dissemination of RAMP can be seen as successful. Preliminary reports on the tool use effects indicate that the RAMP tool supports the MSD risk management process in the work to reduce MDS risks at workplaces.

Linda M. Rose, Jörgen Eklund, Lena Nord Nilsson

The Speed Calculated Hand Activity Level (HAL) Matches Observer Estimates Better Than the Frequency Calculated HAL

Hand Activity Level (HAL) can be estimated from observations (HALO), calculated from exertion frequency, F and duty cycle D (HALF) or from speed, S and D (HALS). Data collected by prospective cohort studies were used to compare these methods. There was 75% agreement between HALO and HALS (HALS = 1.02 × HALO −0.2, R2 = 0.78, F(1,1003) = 43665, p < .001), but only 30% agreement between HALO and HALF (HALF = 0.21 × HALO + 2.2, R2 = 0.04, F(1,1003) = 71.71, p < .001). HALS was more consistent with HALO since both are dependent on speed, and because HALS can be automated, it is more objective than HALF or HALO in this sample.

Oguz Akkas, Stephen Bao, Carisa Harris-Adamson, Jia-Hua Lin, Alysha Meyers, David Rempel, Robert G. Radwin

Automated Video Lifting Posture Classification Using Bounding Box Dimensions

A method is introduced for automatically classifying lifting postures using simple features obtained through drawing a rectangular bounding box tightly around the body on the sagittal plane in video recordings. Mannequin postures were generated using the University of Michigan 3DSSPP software encompassing a variety of hand locations and were classified into squatting, stooping, and standing. For each mannequin posture a rectangular bounding box was drawn tightly around the mannequin for views in the sagittal plane and rotated by 30 º horizontally. The bounding box dimensions were measured and normalized based on the standing height of the corresponding mannequin. A classification and regression tree algorithm was trained using the height and width of the bounding box to classify the postures. The resulting algorithm misclassified 0.36% of the training-set cases. The algorithm was tested on 30 lifting postures collected from video recordings a variety of industrial lifting tasks, misclassifying 3.33% of test-set cases. The sensitivity and specificity, respectively were 100.0% and 100.0% for squatting, 90.0% and 100.0% for stooping, and 100.0% and 95.0% for standing. The algorithm was capable of classifying lifting postures based only on dimensions of bounding boxes which are simple features that can be measured automatically and continuously. We have developed computer vision software that continuously tracks the subject’s body and automatically applies the described bounding box.

Runyu Greene, Yu Hen Hu, Nicholas Difranco, Xuan Wang, Ming-Lun Lu, Stephen Bao, Jia-Hua Lin, Robert G. Radwin

Can the Revised NIOSH Lifting Equation Be Improved by Incorporating Personal Characteristics?

The impact of manual material handling such as lifting, lowering, pushing and pulling have been extensively studied. Many models using these external demands to predict injury have been proposed and employed by safety and health professionals. However, ergonomic models incorporating personal characteristics into a comprehensive model are lacking. This study explores the utility of adding personal characteristics such as the estimated L5/S1 Intervertebral Disc (IVD) cross sectional area, height, age, gender and Body Mass Index (BMI) to the Revised NIOSH Lifting Equation (RNLE) with the goal to improve injury prediction. A dataset with known RNLE Cumulative Lifting Indices (CLIs) and related health outcomes was used to evaluate the impact of personal characteristics on RNLE performance. The dataset included 29 cases and 101 controls selected from a cohort of 1,022 subjects performing 667 jobs. RNLE performance was significantly improved by incorporation of personal characteristics. Adding gender and intervertebral disc size multipliers to the RNLE raised the odds ratio for a CLI of 3.0 from 6.71 (CI: 2.2–20.9, PPV: 0.60, NPV: 0.82) to 24.75 (CI: 2.8–215.4, PPV: 0.86, NPV: 0.80). The most promising RNLE change involved incorporation of the multiplier based on the estimated IVD cross-sectional area (CSA). This multiplier was developed by normalizing against the IVD CSA for a 50th percentile woman. This multiplier could assume values greater than one (for subjects with larger IVD CSA than a 50th percentile woman). Thus, CLI could both decrease and increase as a result of this multiplier. Increases in RNLE performance were achieved primarily by decreasing the number of RNLE false positives (e.g., some CLIs for uninjured subjects were reduced below 3.0). Results are promising, but confidence intervals are broad and additional, prospective research is warranted to validate findings.

Menekse Salar Barim, Richard F. Sesek, M. Fehmi Capanoglu, Sean Gallagher, Mark C. Schall, Gerard A. Davis

Difference of Actual Handled Weight and the Recommended Limit for Dynamic Asymmetrical Manual Handling Tasks in Chilean Construction Workers

Manual handling is a risk factor with high attributable fraction in lumbar pain, frequent injury among construction workers due to dynamic and complex tasks. The aim of this study was to establish the differences between the actual handled weight and the recommended weight limit (RWL) according to EC2 (Ergo Carga Construcción) evaluation method. The study was an analytic and non-experimental cross-section carried out in 32 construction sites with a sample of 186 workers. The positions assessed were bricklayer, scaffolding assembler, carpenters, hand laborers, construction laborers (excavation laborer/safety carpenter) and ironworkers during weight handling tasks. The EC2 method is designed to assess Dynamic Asymmetrical Manual Handling Tasks (DAMHT) and as result, estimates the Recommended Weight Limit (RWL) per task.Within the group 179 DAMHT were assessed. In the sample the actual handled weight was between 3 kg and 80 kg, with a median of 20 kg (ICR = 20 kg). Meanwhile the values of the RWL were between 1.8 kg y 28.7 kg, with a median of 7.31 kg (ICR = 3.37 kg). Generally, all positions handle weights above the RWL established by EC2. The analyzed sample has a difference of 10.98 kg (ICR 23.4), between the actual handled weight and the RWL. The exception are the construction laborers (excavation laborer/safety carpenter), who present a negative difference, while hand laborers (15.69 kg/ICR 25.84), bricklayer (15.17 kg/ICR 23.28) and ironworkers (10,7 kg/ICR 24,62 kg) presents the highest difference among the group.Contrasting research data with limits allowed by Chilean Law (Law 20.949 – maximum limit of 25 kg), a 33% of the sample performs DAMHT above lawful limits. 5% handle weights above 50 kg with a maximum of 80 kg. Regarding the RWL 83.2% of the manual handling observed is above this limit, therefore they imply high physical workload, thus the intervention must be not only with a technical approach but with administrative and engineering actions.

Olivares Giovanni, Villalobos Victoria, Rodríguez Carolina, Cerda Eduardo

A Presentation of the Ergonomic Analysis of Risk Factors in Productive Sectors of Chile and Their Relation with Upper Limb Musculoskeletal Symptomatology

This study aims to identify musculoskeletal health conditions present in a population that works in several different productive sectors in Chile in order to determine the physical risk factors in that type of labor and relation between these risk factors and upper limb musculoskeletal symptomatology. An analytic, nonexperimental, transversal association study was carried out with a sample of 390 worker’s tasks, confidence level of 95%, standard deviation of 5% and maximal variability. Representative task per trade-workers of six different sectors was evaluated. Results describe most representative physical risk factors. In industrial sector were: posture and strength; in service sector: repetitive movement and force factors; in mining sector: repetitive movement and posture and strength; in agriculture sector: repetitive movement, posture and recovery time; in construction sector: posture, repetitive movement and strength; in aquaculture sector: repetitive movement and recovery time. There was a high prevalence of musculoskeletal complaints, of 69,74% in the sample evaluated with Nordic Musculoskeletal Questionnaire. There was no association between musculoskeletal health condition and identification of risk factors (Fisher p-value 0,587). Statistically significant association was found between physical risk factors identified and specific productive sectors chosen (p-value = 0.0001). There is a high prevalence of musculoskeletal symptoms in all productive sectors studied. Productive sectors that present most specific risk factors are Aquaculture, Agriculture, and Industry Sector and this translates into a high prevalence of physical risk factors. The model of the applied tools is efficient to perform the surveillance of the ergonomic risk factors and the musculoskeletal health condition.

Cerda Leonidas, Cerda Eduardo, Olivares Giovanni, Villalobos Victoria, Antúnez Marcela, Rodríguez Carolina

The Relationship Between MRI Parameters and Spinal Compressive Loading

Intervertebral disc (IVD) is a leading source of Low back pain (LBP). The health and functions of the IVD are determined by the inherent biomechanical properties of the IVD and its interaction with external mechanical loading. Quantitative Magnetic Resonance Imaging (MRI) parameters have the potential in detecting loading-induced changes in biomechanical properties of the IVD. T, T2 and Apparent Diffusion Coefficient (ADC) were obtained with a 7T MRI scanner from 20 functional spinal units (FSU) before and after receiving compressive loading of 263.27 N for 60 min. Compressive loading was found to significantly reduce T and T2 but not ADC, indicating that T and T2 had the potential to detect loading-induced changes in biomechanical properties of the IVD. These parameters may provide more sensitivity and specificity to understand the injury mechanism of the IVD and contribute to early diagnosis of IVD degeneration.

Jie Zhou, Fadi Fathallah, Jeffery Walton

Analysis of the Activity: 12 Years of Experience in Using a Data-Acquisition Platform by a French Occupational Health Service Working in Various Companies

In 2005, the ACMS (SIST) occupational health service introduced innovation, by using a data-acquisition platform in order to make the analysis of the situation of real work easier.

Regine Codron, Sonia Bahiri, Patrick Bruneteau, Véronique Delalande, Michel Dupery

The Influence of Psychosocial and Patient Handling Factors on the Musculoskeletal Health of Nurses

Psychosocial work demands, the level of organisational support, and the provision and implementation of a patient handling programme have been identified as important determinants of musculoskeletal disorders (MSD) in nurses. The aim of this study was to describe the prevalence of MSD and explore the association of work-related psychosocial and patient handling factors on the musculoskeletal health of New Zealand (NZ) nurses. A sample (N = 201) of NZ nurses from the 2013 NZ Census completed an online survey in 2016–17 (45% of those eligible). MSD prevalence was measured using a modified version of the Nordic Musculoskeletal Questionnaire. Psychosocial work demands were measured using The Copenhagen Psychosocial Questionnaire (COPSOQ II). Components of “The Tool for Risk Outstanding in Patient Handling Interventions (TROPHI)” assessed patient handling practices. Binary logistic regression provided measures of association between psychosocial and patient handling factors, and MSD. The overall prevalence of MSD was 58% in the previous 12 months and 31% for the last 7 days. Low back (55%) and shoulder (54%) complaints were the most frequently reported MSD during previous 12 months, and co-morbidity of symptoms was high (59%). Higher work pace and emotional demands were significantly associated with MSD. Completing a patient handling task without equipment when equipment was prescribed, and perceived lack of suitable equipment, space, environment, skills or knowledge affecting patient care were also significantly associated with MSD. Interventions for the prevention and management of work-related MSD in nurses should take a multifaceted approach inclusive of physical and psychosocial components embedded within a comprehensive patient handling programme.

Mark G. Boocock, Fiona Trevelyan, Liz Ashby, Andy Ang, Nguyen Diep, Stephen Teo, Felicity Lamm

DUTCH: A New Tool for Practitioners for Risk Assessment of Push and Pull Activities

Pushing and pulling at work is an undervalued theme within occupational health policy. This is unjustified, because these activities are very common and potentially increase the risk of shoulder symptoms. Gaining insight into the possible health risks of specific push or pull activities at the workplace is a first step towards prevention of musculoskeletal symptoms. Existing instruments proved to be insufficiently suitable to give that insight in a simple way. This was the motivation for developing the Push and Pull Check (DUTCH). This method makes clear whether the push or pull activity is acceptable or not, which risk factors exist, and which measures can reduce the risk. This article describes the operation of the DUTCH, as well as the development of the tool.

Marjolein Douwes, Reinier Könemann, Marco Hoozemans, Paul Kuijer, Hetty Vermeulen

Ergonomic Intervention for Healthcare Workers and Patients: A Development of Patient Handling Device

Over the years, healthcare workers have suffered debilitating musculoskeletal disorders when lifting, transferring and repositioning patients manually. Hence this study focuses on risk-related issues experienced by healthcare workers as well as their patients due to manual patient handling. Issues regarding patient handling activities were analyzed by conducting a survey on healthcare workers and patients that includes ergonomic assessment tools like Rapid Upper Limb Assessment (RULA), NIOSH Lifting Equation, and Nordic Musculoskeletal Questionnaire (NMQ) etc. After which, one-way ANOVA and Tukey’s HSD Test were conducted to determine a significant difference between the risk factors on patient handling activities. As a result, healthcare workers tend to experience discomfort mostly on their upper limbs due to equipment’s dimensions and capacity to lift. To address the problem, this study suggested an intervention for the most critical patient handling activity by proposing a patient handling device. The design of the device was based on healthcare workers and patients’ needs and requirements which were translated using Quality Function Deployment (QFD) and Detail Design. For validation of the product, Design Failure Mode and Effect Analysis (DFMEA) and survey regarding user’s perspective of the product were conducted. To test the effectiveness of the proposed design, RULA and NIOSH Lifting Equation were also utilized and the results were compared to the ones obtained before the intervention. Through this, it was confirmed that the proposed design captures critical patient handling activities and offers more functions and features than the available lifting equipment with a lower cost.

Rex Aurelius C. Robielos, Karla Coleen A. Sambua, Joanna G. Fernandez

Up to Our Elbows in Ergonomics: Quantifying the Risks of Bovine Rectal Palpations

Musculoskeletal disorders (MSD) are common in food animal veterinarians. A recent mail survey of Canadian bovine veterinarians found that discomfort was most common in the shoulder, and that bovine rectal palpations were considered one of the most physically demanding tasks. The present preliminary pilot further analyzed the potential association between MSD and rectal palpations using both survey data and observational methods. Statistical analysis of the mail survey results found a non-significant increased odds of shoulder trouble when performing high numbers of rectal palpations, significant protective effects due to years of experience, number of co-workers, and being female, and significant increased odds of shoulder trouble when devoting under 50% of practice time to cattle. A field ergonomic assessment of veterinary bovine rectal palpations using the Rapid Upper Limb Assessment (RULA) method identified several awkward postures associated with the task and consistent scores greater than 6. The combined results suggest bovine rectal palpations hold the potential for hazardous biomechanical exposure if performed at high frequencies, and warrants further study in order to develop prevention strategies.

Robyn Reist, Brenna Bath, Murray Jelinski, Catherine Trask

Analyses of Musculoskeletal Disorders Among Aesthetic Students Applying the Methods: REBA, Nordic and FSS

The number of professionals and the demand for aesthetic treatments has been increasing significantly. During a treatment, the worker could be in non-ergonomic positions and practice repetitive movements, that it may cause Work Related of Musculoskeletal Disorders (WRMDs). These injuries can be prevented if identified in through Ergonomic Analysis of Work (EAW), therefore the aim of this study consist in analyse the harm caused by the activities developed in the clinic during the procedures performed by forty four students of the Aesthetics course of a University. The research developed by applying ergonomics questionnaires REBA and Nordic that evaluate the movements, positions of work and identify pain/discomfort in the body during the performance. The fatigue severity scale also evaluate the fatigue at the beginning, middle and end of the beautician’s session. The REBA was completed according to the observer’s assessment, showed that the majority of the students presented medium-level and high risk, which means that they could develop musculoskeletal disorders. The fatigue severity scale measured the fatigue and verified that the students feel tired by performing repetitive movements. The results show that the majority of the students feel pain and/or discomfort in several parts of the body, the lower back was the region that obtained the highest number of complaints, followed by the upper back and neck. In addition to the analysis of muscle injuries, the research point out the importance of ergonomics studies to improve the quality of life of the aestheticians.

Gabriela de Souza Raymundo, Ivana Salvagni Rotta

Push and Pull – Force Measurement Updates, Interpretation of Measurements and Modes, Peculiarities (Curves, Steps, Etc.). Multi-task Analysis

Push and Pull measurement using conventional instruments such as mechanical dynamometers, does not allow to fully appreciate the peculiarities of a path with curves, gradients or variations in the terrain.High-sampling digital dynamometers allow to accurately observe the performance of the force during push and pull activities.It’s possible to identify:The Initial Force by recording the peak in the initial phase;The Sustained Force by recording the entire phase after the peak: in this case, the value should be processed as a 50th, 75th or 90th percentile of the sample of data recorded, because the percentile concept approximates the classical interpretation of the Sustained Force, according to proposed criteria by Stover H. Snook and Vincent M. Ciriello, authors of the benchmarks for the push and pull activities of the International Standard ISO 11228-2.In various measurement experiences carried out in working environments such as urban waste management, hospital departments, or manufacturing departments, it has been observed that sustained force is not constant, but also varies rapidly. These variations are intrinsic to any handling activity, but introduce a further difficulty in defining the value of this factor.During the shift operators are exposed to multiple handling tasks: it’s important to set up a multitask analysis push and pull activities.Curves, steps and gradients introduce additional variables to the Multitask Analysis.The analysis of the various situations allows to create a database of useful data to map the risk in advance.

Marco Cerbai, Marco Placci

The Characterization and Evaluation of an Intervention to Reduce Neonate Whole Body Vibration Exposures During Ambulance Transport

Newborn infants delivered in a compromised health state often require transport between secondary and primary care hospitals. The objective of this study was to measure and characterize the WBV exposures during simulated newborn infant inter-hospital ground transport and determine how vehicle-based vibration is transmitted through the chain of equipment used to support newborn infants and whether there is a need and potential for mitigation of these exposures. A simulated newborn infant was transported over a 46-min, 32 km route between two hospitals to simulate a typical transport route. The route was completed with a standard transport system as well as a new, modified vibration dampening transport system. The average-weighted vibrations and the vibration dose values were calculated. Relative to the floor measured vibration (0.36 m/s2), the standard transport system amplified the average weighted vibration through the chain of equipment nearly doubling the vibration at the interface where the simulated neonate rested (0.67 m/s2). With the new system, the vibration at the point just above the suspension system was almost half (0.25 m/s2) of the floor measured vibration (0.44 m/s2), but then increased to a maximum of 0.48 m/s2 at the interface where the simulated neonate rested. Results were similar for VDV exposures. When comparing the two systems, the standard stretcher amplified the floor measured vibration by 86% whereas the new stretcher system with the built-in suspension amplified the vibration by just 9%. Options for further investigation and mitigation of vibration in future studies is discussed.

Dawn M. Ryan, Adam Lokeh, David Hirschman, June Spector, Rob Parker, Peter W. Johnson

Real-Time Monitoring of the Posture at the Workplace Using Low Cost Sensors

The aim of this paper is to show a method that can be used to monitor the human posture in an industrial environment. The method is based on the fu- sion of the data coming from two different sensors: a time-of-flight camera (Microsoft Kinect V2) and a wearable motion capture system that uses inertial measurement units to identify the body posture (Notch Wearable). The combined use of these two systems overcomes the intrinsic limitations of the two methods, deriving from occlusions and electromagnetic interferences, respectively. First, the algorithms implemented and the calibration of the two measurement systems in a controlled environment are described. Second, the method applied in a workplace to monitor the posture of the workers during different tailoring operations, is explained. The data acquired have been analyzed in the time domain, and used to compute the cumulative probability density function of different body angles. The results are compared to the subjective evaluation of occupational doctors, and used to compute the OCRA index in an auto- mated way, for the assessment of workers exposure to repetitive movements of the upper limbs.

Marco Tarabini, Marco Marinoni, Matteo Mascetti, Pietro Marzaroli, Francesco Corti, Hermes Giberti, Paolo Mascagni, Alberto Villa, Tammy Eger

A Software Toolbox to Improve Time-Efficiency and Reliability of an Observational Risk Assessment Method

OCRA is a standard risk assessment method addressing manual handling of low loads at high frequency. This method requires the operator to perform a video analysis checking kind and extension of the movements made by workers. The analyst has to take note about number of performed actions and joint angles amplitude. Often this turn out to be a poorly reliable and time-consuming operation because of the inherent 2D nature of the data. The main goal of this work was to design a software toolbox able to support the operator in collecting, organizing and analyzing the information to obtain the Checklist OCRA index in a more reliable and time-effective way. This toolbox presents three different GUIs to: (1) support the operator in counting the number of technical actions; (2) help the operator in determine the percentage of time in which the worker has an incorrect upper limb posture; (3) automatically perform posture analysis considering real 3D angles data acquired through an IMU-based movement analysis system. Preliminary analysis on reliability was performed on three different operators. Obtained findings confirmed our hypothesis; the automatic analysis, in particular, reduced significantly intra- and inter-operator variability thus making the analysis more objective and reliable. Further evaluations will include structured assessment including several operators with different expertise levels and collecting information about user experience (usability, GUI design, etc.) and overall performance compared to standards (operation time and results accuracy).

Stefano Elio Lenzi, Carlo Emilio Standoli, Giuseppe Andreoni, Paolo Perego, Nicola Francesco Lopomo

Musculoskeletal Disorders Among Orthodontists: Risk Factors and Ergonomic Intervention

Musculoskeletal disorders (MSD) prevalence was highest among the orthodontists and oral physicians compared to the general population working in different environments. This study aims to explore ergonomic issues in the orthodontic workplace in small to medium-scale dental clinics in Metro Manila. Assessments were made on the physical workstation set-up of the orthodontic clinic – the design, equipment, tools/instruments, environmental hazards, and the manner in which the workers perform their tasks. The Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) and the National Institute for Occupational Safety and Health (NIOSH) Generic Job Stress Questionnaire were used to gather critical information about MSDs. Anthropometric measurements were taken and used in the Rapid Entire Body Assessment (REBA) to determine the most risky orthodontic tasks. It was found that all orthodontists reported body pains and the highest occurrence had been in the neck (87%), lower back (87%), shoulders (83%), upper back (80%), and forearms (77%). The factors significantly associated with the discomfort scores were age, weekly working hours, workload, and posture. Among the tasks most commonly performed, tooth extraction puts the orthodontists at the highest risk of developing MSDs. To reduce the prevalence of MSDs symptoms among Filipino orthodontists, some of the ergonomic interventions are (1) designing ergonomic workstations to better fit the population, (2) employing certain administrative controls and (3) modifying how tasks are performed.

Rianina D. Borres, John Ulric Lim, Rex Aurelius Robielos, Marquin Jose Pacaña

Quantifying Vertebral Endplate Degeneration Using the Concavity Index

A novel morphometric measurement of endplate degradation was compared with qualitative ratings of intervertebral disc degeneration (Pfirrmann Grading) in a double-blinded study to investigate a new, quantitative method for relating disc morphology and bony changes using MR imaging techniques known as the “Concavity Index” (CI). By adding a quantitative measure of vertebral endplate degeneration, the CI could provide further insight into structural changes related to disc breakdown and subsequent low back pain. The continuous nature of the CI may also allow medical professionals to more closely monitor a patient’s low back health. T2-weighted MRI scans of the sagittal profile of the lumbar endplates (L2-S1) were collected from 50 subjects (25 females and 25 males) whose ages ranged from 20–40 years. Three trained examiners independently measured the height and the concavity levels of each lumbar vertebrae (L2-S1) as well as assessed the health of the intervertebral discs using Pfirrmann’s lumbar disc degeneration grading method. Concavity Indices (CIs) were computed by dividing measured concavity level by disc height (CL/DH). A larger CI was hypothesized to be indicative of spinal degradation and subsequent low back pain. Intra- and inter-rater reliabilities were assessed for both the CI measurements and Pfirrmann’s lumbar disc degeneration grades. The categorical intra-observer agreement for Pfirrmann ratings ranged from 26 to 63%. However, the CI, which is a continuous measure, varied by only 2% (average absolute error) among raters. Endplate concavity is indicative of fracturing and damage and is hypothesized to lead to subsequent disc degeneration due to impediment of nutrient flow to the discs themselves. The CI shows promise as a means for potentially quantifying low back health and identifying risk for future low back pain prior to significant disc degeneration.

Menekse Salar Barim, Richard F. Sesek, M. Fehmi Capanoglu, Wei Sun, Sean Gallagher, Mark C. Schall, Gerard A. Davis

Evaluating the Reliability of MRI-Derived Biomechanically-Relevant Measures

Human geometric dimensions have been estimated and approximated in several ways, most recently using Magnetic Resonance Imaging (MRI) techniques. The reliability of MRI-based measurement of structures has been shown to be relatively high. However, a limitation of reliability evaluations is that they often only compare assessments of the same MRI image (e.g., “slice” of the back); differences are only a function of analyst dexterity (in tracing or measuring the structures). Ideally, a reliability test should compare estimates of biomechanical structures using different scans analyzed by different analysts. This presents a “worst case” scenario and provides a robust test of the process’s repeatability. Existing databases of vertebral and intervertebral dimensions tend to be limited with respect to measures of repeatability/reliability with relatively narrow study populations and/or parameters recorded. The objectives of this study were (1) to provide a more accurate data set of lumbar spinal characteristics from 144 Magnetic Resonance Imaging (MRI) scans which were reviewed and measured using the Osirix software program and (2) to assess inter- and intra-rater reliability of the MRI process itself. Reliability for the entire process was evaluated using the aforementioned worst-case scenario of comparing two distinct scans of the same subject with different researchers performing each MRI scan and different researchers performing measurements of the various aspects of vertebral and intervertebral disc dimensions. Geometric dimensions were consistent with measurements obtained in previous MRI-based studies. As expected, larger discrepancies were observed in the “worst case” scenarios (scanners and analysts both different). However, worst case variation was relatively low with 3.6% average absolute difference for anterior endplate measurements, for example, as compared to 2.6% average absolute difference for analysts re-rating their own scans after 1 month. The process for obtaining MRI-derived biomechanical measures appears to be robust.

Menekse Salar Barim, Richard F. Sesek, M. Fehmi Capanoglu, Sean Gallagher, Mark C. Schall, Gerard A. Davis

Preventing Back Injury in Caregivers Using Real-Time Posture-Based Feedback

Introduction: Poor posture while performing patient handling tasks is a determinant of low back injury in caregiving settings. Traditional training programs relying on lecture-based teaching of body mechanics has shown to be ineffective. The use of real-time feedback during caregiving tasks has potential as an alternative training intervention.Objectives: This study aimed to investigate the effectiveness of PostureCoach, a device for providing real-time feedback based on spine posture, in reducing the time participants spend in extreme flexion postures during caregiving tasks, as well as the user acceptability of the device as a training tool.Methods: Eleven novice participants were recruited and divided into intervention (n = 9) and control (n = 2) groups. They were asked to repeat a set of simulated care activities eight times over two separate sessions held on consecutive days. Individuals in intervention group received real-time auditory feedback in some trials when their forward spine flexion exceeded a threshold, while the participants in control did not. Changes in the amount of forward flexion in the lumbar spine was compared between groups and across trials.Results: PostureCoach reduced the amount of extreme (80th percentile and 95th percentile) spine flexion during caregiving tasks. This reduction indicates that the participants using PostureCoach reduced their risk of back injury compared to the control group.Conclusions: PostureCoach shows potential as a wearable device to train novice healthcare professionals and home caregivers for back injury prevention.

Mohammadhasan Owlia, Chloe Ng, Kevin Ledda, Megan Kamachi, Amanda Longfield, Tilak Dutta

Equotherapy Center at a Glance for Ergonomic Activity: Epidemiological Profile Versus Therapeutical Practices

An ergonomic study at an equotherapy center – method in which a horse is used as the mean to promote the handicap people, positive results according to the individual therapeutical objectives for the rehabilitation of themselves. The study has its primary focus, the equotherapeutical personnel who faces on the therapeutical attendance, constraints by the biomechanical efforts. The demand reflected on identifying, knowledge need and comprehend how to establish the activities done by the professionals. The study was based on the Ergonomic Work Analysis (EWA). On the initial phases of the EWA, a perception questionary was applied in order to characterize. The professional profile, demographic and epidemiological, at the same time with the job description done and its specificity for the professionals. To comprehend the epidemiological profile of the organization, it has been applied the bipolar questionary, resulting in information which brought the activities which cause the major discomfort. Within all the listed activities the major ones detected was “stabilize the practitioners by the horse” and “walking by the horse side.” It has been understood during the data collection, the practitioner diversity, whose biomechanical efforts demanded by the professional vary (practitioner versus therapy). It has been observed that major incidences of discomfort and intensity were identified on the shoulder and forearm. The results allowed to correlate the difficult degree with the epidemiological profile of the professionals. Such understanding allows that each professional adequate the appointment agenda, alternating the daily shift between the cases which demand more or less physical and posture efforts.

Marcelo Dondelli Boaretto, Jullia Maria Rodrigues Zullim, Bruno Sobral Moreschi, Maria de Lourdes Santiago Luz

Patterns and Predictors of Work-Related Musculoskeletal Disorders Among Commercial Tricycle (Keke Napep) Riders in Nigeria

Objective: This study assessed the prevalence, pattern and predictors of Work related Musculoskeletal Disorders (WMSD) among tricycle (keke) ridders in Nigeria.Method: A total of 384 keke riders participated in this cross-sectional study. WMSD was assessed with Cornwell questionnaire while the demographic, job related, and anthropometric variables were assessed with the use of a self-designed interview guide. Data obtained was analysed descriptively using frequency and percentage, mean and standard deviation and inferentially using chi-square and logistic regression. Level of significance was set at α = 0.05.Results: The mean age of the participants was 38.73 ± 10.55 years with a mean ridding duration 8.50 ± 1.39 h/day. The general WMSD prevalence in this study was 79.9%; and was more prevalent at the low back (60.4%), neck (49.7%) and shoulder (39.8%) regions. There was a significant association between the general WMSD and each of ridding with passengers in the front cabin (X2 = 19.156, p < 0.001), vibration (X2 = 28.568, p = 0.001), twist while making a turn (X2 = 39.874, p < 0.001), awkward sitting posture (X2 = 4.243, p = 0.039). Twisting while ridding (OR = 1.006, p = 0.009) and job stress (OR = −1.398, p = 0.01) were the significant predictors of general WMSD.Conclusion: There is a high prevalence of WMSD among Nigerian Tricycle ridders. Job stress and twisting while driving are important predictors of WMSD in this group. Ergonomic training programmes are recommended for this population.

Echezona Nelson Dominic Ekechukwu, Martins Oshomah Okaku, Samson Adaramola, Ifeoma Nmachukwu Onuorah

Effectiveness of a Pain Education Programme for Persistent Work-Related Musculoskeletal Pain

Pain education is an important factor in the self-management of work-related musculoskeletal pain and can help in reduction of pain, disability, anxiety, stress, improved physical activity, positive thoughts, and reduced catastrophising of pain. Hence the objective of this study was to investigate the effectiveness of a pain education programme on workers with persistent work-related musculoskeletal pain in improving knowledge, self-efficacy and reduction in their pain. A survey questionnaire was used to evaluate the knowledge and understanding of the workers regarding pain and a questionnaire was used to evaluate their social and psychological status. The primary outcomes used were the McGill Pain Questionnaire and revised Neurophysiology of Pain Questionnaire. The pre-post analysis regarding the effectiveness of the course programme by analysing the outcomes of McGill pain questionnaire, Neurophysiology of pain questionnaire and the programme evaluation score showed a statistically significant difference in the post-scores compared to the pre-scores. This showed that the pain education programme was effective in the reduction of pain, disability and better conceptualisation of pain.

Deepak Sharan, Joshua Samuel Rajkumar

Co-morbidities of Myofascial Low Back Pain Among Information Technology Professionals

Co-morbidity can be defined as the presence of one or more disorders (or diseases) in addition to a primary disease or disorder, or the effect of such additional disorders or diseases. The underlying basis for such studies is that if there is a presence of two or more diseases simultaneously, they may have a common origin. Myofascial Pain Syndrome (MPS) of the lower back or Myofascial Low Back Pain (MLBP) is one of the commonest WRMSD noted among IT professionals. The aim of this study was to identify the prevalence of MLBP as a WRMSD and its co-morbidities among IT professionals. The data was collected from 8500 IT professionals from a single IT company who visited the on-site clinics situated at their office campuses in 8 cities in an Industrially Developing Country. All the reports from the year 2005 to 2017 which were maintained in a database were reviewed. The study participants were predominantly males (78%). The mean age of the male and female subjects were 33.30 ± 5.99 years and 27.38 ± 5.59 years respectively. 44% of the population used laptops, 42% desktops and 14% both. 48.5% of the participants had MLBP. MLBP was the third common WRMSD, following MPS of neck and Thoracic Outlet Syndrome. The present study revealed that MPS of neck, Thoracic Outlet Syndrome, Fibromyalgia Syndrome and Patellofemoral Pain Syndrome were found to be co morbid among IT professionals with MLBP.

Deepak Sharan

Application Study: Biomechanical Overload in Physiotherapists

Healthcare professionals, especially Physiotherapists (PTs) are highly predisposed to WRMSDs. PTs tasks are generally complex and involve many physical activities that can lead to acute and chronic WRMSD, e.g., shifting the patient from one position to other or while performing manual therapy techniques. The Timing Assessment Computerized System (TACO) method was used to evaluate the risk of WRMSD among PTs and its relationship with musculoskeletal symptoms, exertion and workload. A prospective experimental study was conducted among a group of 55 PTs working in a rehabilitation center. The results of the study showed that 80% of PTs reported pain. The predominant posture causing high risk was “lumbar spine fully bent with operational areas under the knee” (54%). The commonest site of pain was lower back (60%), neck (52%) and upper back (50%). 80% of the participants were in the High Risk/Very High Risk category according to the TACO outcome.

Deepak Sharan, Joshua Samuel Rajkumar, Rajarajeshwari Balakrishnan

Why Do Information Technology Professionals Develop Work Related Musculoskeletal Disorders? A Study of Risk Factors

Work Related Musculoskeletal Disorders (WRMSD) are highly prevalent among Information Technology (IT) professionals. A prospective analysis of 8200 IT Professionals (age 20 to 60 years, mean 33 years, 74% males), in an Industrially Developing Country was conducted. The employees were evaluated by a detailed questionnaire consisting of demographic data, job details, health status, physical risk factors, short-form Work Style Questionnaire and Nordic Musculoskeletal Pain Questionnaire. pain (36%). Musculoskeletal problems increased the fatigue levels as recorded by Borg CR-10 scale. 76% of the employees were diagnosed by an experienced occupational health physician to have a WRMSD, among which 65% of the employees were laptop users. 78% had widespread body pain, 72% neck pain, 63% lower back pain, 52% shoulder pain and others with upper arm, thigh, knee and foot pain. Increasing age, high Body Mass Index, longer working hours, hazardous body postures, static loading, resting elbows and wrists on hard surfaces, and adverse work-style were positively correlated (r < 0.01) with the presence of WRMSD. On the other hand, rest breaks during work, regular exercises and formal ergonomics training were negatively correlated (r < −0.01).

Deepak Sharan, Joshua Samuel Rajkumar

The Ergo-UAS System and a New Design Approach: Overview and Validation

Musculoskeletal disorders are the second largest contributor to disability worldwide affecting people across the life-course. Risk identification and design of interventions to reduce the rates of work-related musculoskeletal disorders need to be based on valid and reproducible methods. The Ergo-MTM model is a method used for balancing and design purposes based on the definition of standard time that considers at the same time two of the most important issues in the definition of a fair load. The innovative aspect, is the definition of the Ergonomic Factor determined for every workplace accordingly to the biomechanical load coming from the combination of the assigned operations and quantified with EAWS method. The concept is based on recent relevant standards related to the biomechanical load, which is influenced by the sequence, the repetitiveness and frequency of the operations, in addition to the characteristics of every movement. In the paper the methodology of the project of validation through longitudinal epidemiological study of the EAWS system for the assessment and prevention of biomechanical overload will be presented. Fondazione Ergo and University of Bologna are carrying out the study with the scientific contribution of a panel of experts from academic and non-academic institutions and the Bioethics Committee of the University of Bologna.

Gabriele Caragnano, Roberta Bonfiglioli

Development of a Risk Assessment Procedure for Upper Limbs Based on Combined Use of EAWS 4th Section and OCRA High Precision Checklist

Italian legislation on the subject of Workers’ Health and Safety recalls the ISO standards for the ergonomics analysis and mentions the OCRA method as ‘preferred’ for risk assessment of upper limbs overload. Over the years, other methods for ergonomics risk assessment not currently mentioned in ISO Standards, were developed. As for example, EAWS method – proposed by International MTM network for ergonomic design and analysis of workstations – is greatly adopted by automotive OEMs because of its integration in the ErgoUAS system that allows to define the sequence of tasks and the time needed to perform related to the biomechanical load. This paper presents the “Cut Off” Project developed to define a risk assessment procedure for upper limbs based on the combined use of EAWS section 4th and OCRA Checklist. “Cut off” are a set of criteria, related to the main risk factors for upper limbs musculoskeletal disorders, characterized by threshold values based on EAWS section 4th. The aim of the procedure is to apply EAWS section 4th to all manual workstations during both design and risk assessment phase and to analyze with OCRA checklist only workstations, characterized by the overcome of one or more thresholds based on EAWS factors. The procedure is going to be constantly monitored and possibly improved by new data collection.

Enrico Occhipinti, Lidia Ghibaudo

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