Sports Biomechanics Analysis: Assisting Effectiveness Evaluations for Wearable Compliant Elbow Joint Powered Exoskeleton

Wearing an exoskeleton, the human body constantly experiences mechanical loading. However, quantifying internal loads within the musculoskeletal system remains challenging, especially during unconstrained dynamic activities such as manual material handling. Currently, exoskeleton systems are commonly integrated with sensor technologies to gather data and assess performances. This is mainly performed to evaluate the physical exoskeletons, and cannot provide real-time feedback during the development phase. Firstly, a powered wearable elbow exoskeleton with variable stiffness is proposed. Through theoretical calculation, the power efficiency formula of exoskeleton is derived. Then, a human musculoskeletal model is built using the AnyBody Modeling System and coupled to the elbow exoskeleton. Under set experimental conditions, the simulation reveals that, when compared with the exoskeleton, the biceps and triceps muscle force parameters of the human model were reduced by 24% and 12%. The muscle activity was diminished by 28–31%, and muscle length shortened by about 6%, in comparison to the condition without the exoskeleton. Finally, through the muscle force experiment, it was verified that the power efficiency of the elbow exoskeleton in the real transport was about 18%. The project reduces costs in the development phase of the exoskeleton and can provide new insights into muscle function and sports biomechanics.