Physics-based Ankle Kinematics for Estimating Internal Parameters

Abstract

This paper presents a kinematic model and its inverse solutions to identify internal ankle parameters in sagittal plane from external motion data; the effects of initial guesses and noise on the solutions are discussed. Experiments were designed to eliminate skin-marker errors in motion data, and performed to validate the model and the estimation method experimentally by comparing estimations with measurements from the computed tomography scan of the ankle. Based on observations that the skin temperature of bony prominences is lower than that of muscle, a novel infrared (markerless) method to locate bony prominences as features is conceptualized; experiments suggest that this concept feasibility is promising.