Assessment of Isometric Pulls Strength of Industrial Cart Pullers -An Electromyography Study from an Apparel Manufacturing Industry

Abstract

Manual material handling and occupational tasks demanding physical push-pull activities are very common in various industrial settings regardless of automation. These activities may become the cause of fatigue, accidents and/or different occupational hazards if not properly focused to balance workload as per physical strength and stamina of the worker. This cross-sectional study was conducted to assess the isometric pull strength of apparel cart/trolley pullers and muscular activity of upper limbs. Jackson strength evaluation system was used to measure isometric pull strengths while IXTA Data Acquisition System to measure and analyze the muscle activity. The experiments were conducted with twenty work-in-process (WIP) manual material handlers of an apparel manufacturing industry. Electromyographical (EMG) data of muscle activity was collected by placing electrodes on pronator teres, brachial biceps, pectoralis major and lower trapezius muscles during the pull tasks. The results show that torso pull in seated posture has the maximum isometric average value of 62.20 ± 5.91 kg while arm lift has the minimum strength value of 37.10 ± 4.61 kg. Assessment of muscle fatigue caused by pulling force is important in determining job severity of workers and mitigating occupational injuries which help in balancing workloads for effective management.