The Influence of workload measures by weight, repetition and height during one-handed handling

This study aimed to evaluate the workload effect of weight, repetition and height between muscle activity and fatigue, and perceived fatigue during one-handed handling. Twenty-five right-handed male subjects performed lifting and lowering tasks for 10 min under varying conditions: weight (1, 4 and 7 kg), repetition (2, 6 and 10 cycles/min) and height (30, 60 and 90 cm). Electromyography signals were recorded from the anterior deltoid, posterior deltoid and upper trapezius muscles. Instantaneous energy (IE), instantaneous mean power frequency (IMPF) and perceived fatigue were analyzed. Results showed that increased height led to a 172.3% rise in mean IE, higher repetition reduced IMPF by 6.0% and increased weight raised perceived fatigue by 283.6%. Height primarily affected muscle activity, repetition influenced fatigue and weight impacted subjective fatigue. These findings highlight the importance of considering individual risk factors in relation to different workload measures.