A Novel Method for Determining Centers of Rotation of Human Joints

Abstract

Adjustment is necessary for wearable devices such as rehabilitation anthropomorphic leg devices and exoskeletons. However, this is normally done by trial and error and requires a significant amount of expertize. A novel methodology is developed to locate centers of rotation of human joints. The developed methodology is applicable to human joints with fixed centers of rotation, but it is also applicable to knee joints where an equivalent center of rotation can be identified for a given range of motion. The proposed novel methodology involves a device consisting of two slides and procedures of position measurements during flexion/extension which yield the position of a human joint in a Sagittal plane. The third coordinate can be obtained by repeating the procedure in a lateral plane. A theoretical proof is presented based on complex numbers, the proposed system is modeled using Solid Works and results are promising.