Elsevier

Applied Ergonomics

Volume 32, Issue 5, October 2001, Pages 479-483
Applied Ergonomics

Evaluation of physiological work demands and low back neuromuscular fatigue on nurses working in geriatric wards

https://doi.org/10.1016/S0003-6870(01)00025-4Get rights and content

Abstract

This study evaluated the physiological demands and low back neuromuscular fatigue patterns following a daytime work shift of 21 female nurses working in geriatric wards. Subjects’ heart rate (HR) at work was monitored for 8 h and surface electromyogram (EMG) of their back muscle was recorded during a 1-minute horizontal trunk holding test before and after work. Results showed that the nurses had heart rates exceeding 90 beats/min in 57% and 110 beats/min in 19% of their working hours. The EMG revealed a significant drop in initial median frequency (MF) (p=0.04) and increase in negative slope of the MF/time plot (p<0.001) of the back muscle after work. These suggest that the muscles were fatigued after work. The nurses rated patient lifting, transfer and turning as most physically demanding, and these corresponded to the highest heart rates recorded. The physiological and neuromuscular strain on the nurses indicated that extreme care should be exercised at work, particularly towards the end of a work shift when the muscles have become fatigued.

Introduction

Nurses working in geriatric settings are at higher risk of musculoskeletal injury compared with nurses in other specialties (Lusted et al., 1996). The prevalence of injury among nurses in geriatric settings is reported to be 92%, which probably reflects the heavy physical demands of nursing care where patients are more physically dependent and potentially less cooperative than other settings (Collins and Owen, 1996). Ryden et al. (1989) have hypothesized that the risk of injury increases towards the end of the shift commensurate with increasing muscle fatigue. Thus, a given load experienced by the back muscle at the end of the shift can contribute to back strain when superimposed on cumulative back muscle fatigue, compared with the beginning of the shift, when the load produces less untoward effect.

The physical demands of various occupations have been of interest to investigators. Jensen (1987), for example, reported that nurses, garbage collectors and warehouse workers experience similar physical work demands in terms of lifting, and that these occupations have similar rates of musculoskeletal injury. Klein et al. (1984) concurred that the frequency of lifting for nurses was comparable to that for construction workers. Because of the high prevalence of injury in this profession, nurses have been reported to regard work-related injury as “inevitable” in their professional life (Garg et al., 1991).

Although studies have examined physical work profiles and work-related injuries of nurses with on-site observations (Lo et al., 1993), self-report questionnaires (Lusted et al., 1996), longitudinal epidemiological study (Yassi et al., 1995), and ergonomic analysis in the work place (Hignett, 1996), study of nurses in geriatric settings warrants special attention given current health care trends that there is increasing need for health care professionals in the specialty of geriatrics. Furthermore, the associated physical demands of geriatric settings is particularly taxing to the frontline workers due to the high proportion of women, who are generally less strong than men, working in this profession.

Cognizant of the lack of information in the physical work demands of nurses working in geriatric specialty, the specific purposes of this study were: (1) to compare subjective rating and objective measures of intensity of nursing activities in a geriatric setting; and (2) to compare back fatigue in nurses before and after a standard day shift.

Section snippets

Subjects and research design

The subjects included female nurses (n=21) with a mean age of 27.3 yr (standard deviation±4.99) currently working in a geriatric rehabilitation ward of a general hospital. Inclusion criteria were being female nurses working frontline, in good general health, normal weight, and not pregnant at the time of study. In addition, subjects were to have a minimum of 2 yr work experience in a geriatric rehabilitation setting, and no contraindication to conducting their normal patient care

Results

Baseline HR (mean±standard deviation) recorded by the nurses in the morning was 65±4.1 beats/min. The HR ranges and proportion of time spent in each HR range by the nurses are shown in Table 1. The data revealed that HR exceeded 90 beats/min in 57% of the shift, and exceeded 110 beats/min in 19% of the shift.

Table 2 shows the routine work duties identified by the nurses that they encounter daily. Of these, they rated turning, transferring, and showering patients as the most physically demanding

Discussion

The nursing profession has been recognized as having high physical demands at work (Engels et al., 1994; Lusted et al., 1996). Our results indicate that the intensity of nursing activities performed in a geriatric rehabilitation setting vary widely over an 8-hour day shift, i.e., from low intensity such as paper work to high intensity such as transferring a patient alone.

Assuming the maximum HR to be 220 minus age, the HR data can be converted to relative workload using the formula (HRwork–HR

Acknowledgments

We gratefully acknowledge the Hong Kong Occupational Safety and Health Council for financial support, Caritas Medical Centre of Hong Kong for granting access to the nurses for the present study, and Professor Elizabeth Dean of The Hong Kong Polytechnic University for editorial advice on this paper.

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