A novel measurement of intersegmental forces exerted on human lower limbs during forward falling and regaining balance motions

This study proposes an analysis system for evaluating the intersegmental forces exerted on human lower limbs. In existing analysis systems, the ground reaction force exerted on the feet is generally measured using force plates fixed on the motion trajectory, and the intersegmental forces are then estimated using an inverse dynamics approach. However, force plates are inconvenient and expensive. Accordingly, the present study proposes a method for evaluating the intersegmental forces without the need for force plates. In the proposed approach, the supporting and striding legs are modeled as a seven-link manipulator system, and the intersegmental forces is then derived using Newton-Euler theory. It is found that the estimated results are in good agreement with the actual measurement datum. Thus, the basic validity of the proposed analysis system is confirmed. For application, the intersegmental force would be the major reference datum to design the artificial joints.