The paper aims to examine the redesign of a truck to decrease the biomechanical load on kerbside waste collection workers. Two workers (one man and one woman) simulated unloading 10 kg bins inside the vehicle using five techniques at varying heights and horizontal distances.
We estimated bilateral mean muscle activity as a percentage of Maximum Voluntary Contraction (%MVC) from Anterior Deltoideus, Lateral Deltoideus, Upper Trapezius, and Erector Spinae using sEMG.
The trunk muscles of both workers exhibited the highest %MVC at a height of 145cm. For male, we observed the lowest %MVC values (16% for ESdx and 23% for ESsx) at 105 cm and 135 cm heights. For women, techniques with less overloading with the lowest %MVC values are 105 cm and 185 cm heights. Nonetheless, the combined %MVC values were still high (65%).
At a height of 105 cm, both workers showed the lowest %MVC values for their shoulders.
The highest %MVCs for anterior deltoids were observed in men at a height of 145 cm, while both trapezius muscles showed the highest overall %MVCs at 145 cm and 185 cm heights.
Women exhibited the highest %MVCs for shoulder muscles on the left side at a height of 145 cm, and all TRdx values exceeded 40%. We found that the most overloading was 185 cm height.
Handling techniques at 200 cm height has not been investigated. Workers refused to simulate because too high.
The study findings revealed both negative and positive effects.
We observed adverse effects when workers pulled a wire to open the backdoor of a lorry at a height of 145 cm, which resulted in increased biomechanical load on the shoulders and into a waste of time.
Handle bins at 145 results in a high %MVC due to an increased horizontal distance of 35 cm.
Positive, concern lowering of whole lorry to reduce load for lower limbs in repeated hop on hop off and a reduced handling height of container (135 cm Vs. 105 cm). Additionally, the use of homologated containers will optimize collection round times.
Despite these improvements, there is still a high biomechanical risk, particularly for women. Limitation of the study is the small sample size.
