Examination of evaluation method of bi-articular muscle strength based on joint torques

Abstract

It is very important to quantitatively calculate muscle strength and evaluate exercise in daily training and functional recovery training in the rehabilitation field. The value of joint torque at each joint of the limb is generally used for motion evaluation. However, bi-articular muscles in the limb might act antagonistically on one joint while acting cooperatively on the other joint. This bi-articular muscle action is known to cause lower power output than the power calculated from individual joint torque. Therefore, this study focused on the motion of the upper limb in the horizontal plane, and attempted to determine the relationship between the distribution of tip output and joint torque of each joint, and to simply estimate the muscle strength of bi-articular muscles from the commonly used joint torques.