Lightweight Active Soft Back Exosuit for Construction Workers in Lifting Tasks

Abstract

Low back pain (LBP) is prevalent among construction workers, which causes many LBP sufferers, and consequently leads to corresponding economic and skilled workforce losses. Back exoskeletons are verified to be effective in low back load and damage reduction, but existing devices are restricted by bulky size, heavy weight, and high price. This study proposes a lightweight active soft back exosuit to assist construction workers with overexertion prevention in heavy lifting tasks, and the actuator is innovatively based on McKibben air muscle. This exosuit prioritizes its lightweight, compacted size, flexibility, good breathability, low cost, and providing support as needed. The maximal injected gas pressure of pneumatic artificial muscle (PAM) is 0.20 MPa, and each PAM provides maximum contraction force of 116 N. A biomechanics evaluation suggests the exosuit can provide assistive moment of up to 54.08 N·m. Human subject testing shows significant electromyographic (EMG) signal reduction at longissimus (LG) and multifidus (MF) with the proposed exosuit, and the subject evaluation of the exosuit shows the exosuit was helpful in reducing mental and physical demand and effort. The results suggest the great potential of this exosuit to serve construction management in terms of worker LBP prevention and reducing the corresponding economic and skilled workforce losses. Work-related diseases, particularly low back pain, pose a significant burden in the construction industry, leading to substantial healthcare costs, decreased productivity, and skilled workforce attrition. The etiology of low back pain can be attributed to work-related physical postures, prolonged durations, as well as high physical effort and heavy load. Back exoskeletons have emerged as promising wearable assistive devices, mitigating the impact of these factors by providing external force to share the load borne by the lower back. However, existing exoskeletons suffer from limitations such as bulky size, heavy weight, poor adaptability, and high cost, rendering them unsuitable for construction workers. In this study, the authors draw inspiration from the contraction of human muscles and leverage compressed gas-driven artificial muscles to address the aforementioned shortcomings. The proposed exosuit for construction workers involved in lifting tasks harnesses the power of artificial muscles, providing targeted contraction force to the lower back of users. This force is activated by sensing the intent of users lifting their trunk through integrated sensors within the suit, effectively sharing a proportion of the load on the lower back. The design of the proposed exosuit prioritizes ease of use for construction workers engaged in frequent lifting tasks. By ensuring lightweight construction, compact size, flexibility, and overall device compliance, the solution proposed by the authors overcomes the limitations of existing exoskeletons. Moreover, the proposed exosuit holds significant potential in construction management, offering substantial benefits in terms of preventing lower back pain among workers and curbing associated economic losses and workforce decline.