The Assist Performance Test of Industrial Passive Waist-assistant Exoskeleton on Fatigue during a Repetitive Lifting Task

Abstract

Low back pain is a serious industrial problem and a common chronic disabling disease that affects the health of many workers, with a steadily rising rate of incapacity due to low back pain and a burden on individuals, families, businesses and society. Therefore, a new type of wearable lifting assist device, called the Industrial Passive Waist-assistant Exoskeleton (IPWE), was developed for workers' working conditions to reduce the risk of lower back muscle damage during manual handling. The purpose of this study was to evaluate the impact of this IPWE on the muscle activity and oxygen consumption of the lower back in simulated lifting tasks. Meanwhile, local perceived stress, subjective perceived fatigue and system availability of the exoskeleton system were evaluated. The results showed that the IPWE significantly reduced the muscle activity of the thoracic erector spinaes and lumbar erector spinaes. During the 15-minute repetitive lifting task, the electromyographic amplitudes of the thoracic erector spinae TES1, TES2 and the lumbar erector spinae LES1, LES2 decreased by 19.14%, 14.63%, 28.03% and 25.05%, respectively. In addition, the exoskeleton did not cause significant differences in oxygen consumption and subjectively perceived fatigue. But it caused increased local pressure on the thighs and shoulders. Among them, IPWE was considered to have acceptable availability by half of the subjects. However, the obvious contact pressure on certain body parts were the cause of discomfort caused by IPWE.