Calculation of joint torques during the rising phase of sit-to-stand motion is in most cases indeterminate, due to the unknown thighs/chair reaction forces in addition to the other sources of uncertainties such as joint positioning and anthropometric data. In the present study we tested the reliability of computation of the joint torques from a five-segment model; we used force plate data of thighs/chair and feet/ground reaction forces, in addition to kinematic measurements. While solving for joint torques before and after seat-off, differences between model solutions and measured data were calculated and minimized using an iterative algorithm for the reestimation of joint positioning and anthropometric properties. The above method was demonstrated for a group of six normal elderly persons.
Dept. of Rehabilitation Sciences, Hong Kong Polytechnic Univ., Hong Kong SAR, China
Motor Control Lab, Dept. of Kinesiology, FLOK, Katholieke Univ. Leuven, Tervuursevest 101, 3001 Heverlee, Belgium
Dept. of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa 32000, Israel.