Analytical model for estimating intersegmental forces exerted on human lower limbs during walking motion

• Evaluating the intersegmental forces without the need for force plates.
• Modeling the human lower limbs as a seven-link manipulator system.
• Deriving the intersegmental forces based only on the kinematic data.
• Measuring the kinematic data by gyroscopes and accelerometers.
• Confirming the analytical results by comparing with the experimental data.

Existing methods for evaluating the intersegmental forces acting on the human lower limbs during walking generally measure the ground reaction force exerted on the feet using force plates and estimate the intersegmental forces using an inverse dynamics approach. However, force plates are inconvenient and expensive. Accordingly, the present study proposes an approach for evaluating the intersegmental forces without the need for force plates by modeling the human lower limbs as a seven-link manipulator system. In the proposed approach, the intersegmental forces are derived directly from the analytical model using Newton–Euler theory based on the posture information obtained from a system of gyroscopes and accelerometers during walking motion. The results obtained from the analytical model are compared with the experimental data obtained using load cells. It is found that the estimated results are in good agreement with the measured results. Thus, the basic validity of the proposed analysis system is confirmed.