Wearable stooping-assist device in reducing risk of low back disorders during stooped work

Stooped postures are commonly found in agricultural, construction, mining, and other workplaces all around world, and such workers are estimated to be in the 100s of millions worldwide. The work requiring stooped postures is strongly associated with high incidence of low back disorders (LBDs). According to biomechanics, the ideal static equilibrium model of stooped human body was established. A wearable stooping-assist device (WSAD) was developed as an intervention to reduce thoracic and lumbar erector spinae activity, based the model. Electromyography (EMG) experiments were conducted to evaluate the effectiveness of the WSAD. Results showed that the integrated EMG amplitudes of the thoracic erector spinae (TES), the lumbar erector spinae (LES), the latissimus dorsi (LD) and the rectus abdominis (RA) were reduced by 42%, 47%, 28% and 9% respectively, when sagittal trunk bended forward to 90 degrees from the vertical. By reducing back erector spinae activity, the WSAD is able to reduce low back physical demands during stooped work task thereby decreasing the risk of developing LBDs associated with stooped work.