Squat Lifting Motion Prediction With Heavy Load Considering Dynamic Strength of Knee Joint

This paper studies the knee joint dynamic strength modeling and simulation for squat lifting with heavy loads. The dynamic strength is modeled as a three-dimensional function of joint angle and velocity based on experimental isometric and isokinetic strength data. Then the dynamic strength function is formulated as joint torque limits in an inverse dynamics based optimization formulation. By using this formulation, squat lifting is predicted with heavy loads. An enumeration procedure is introduced to predict maximum lifting weight under various lifting conditions by considering dynamic strength of knee joint. In addition, the effect of lifting speed on the maximum lifting weight is investigated. Several future research directions are identified.