A Musculoskeletal Driven Forward Dynamics Simulation of Swing Phase of Transfemoral Amputee Gait

A forward dynamics computer simulation was carried out to investigate the hip and knee joint kinematics in the swing phase of a transfemoral amputee normal walking. With a Hill- based musculotendon model, the lower extremity was simulated as a two-degree of freedom linkage with the hip and knee as its joints. Kinematic data of hip and knee joints were recorded by a motion analysis system. The calculated hip and knee angles correspond to measured angles. The simulation results are in accord with experimental records of electromyography that show the hip flexors of a transfemoral amputee are overactivated in comparison to a normal subject. The results suggest that this muscle overativation is necessary to achieve a normal hip flexion. In addition, the amputee may use the residual limb muscles to compensate the abnormalities that other components such as shank may produce