Musculoskeletal model of the lower extremity of trans-tibial amputee

To predict and explain the patterns of muscle forces in the stump of a left trans-tibial amputee during walking, and to study the effects of walking speed, Musculoskeletal model is built with the combination of the computer simulation to calculate muscle forces in the trans-tibial stump during walking. Kinematic data and ground-reaction forces are simultaneously recorded by a gait analysis system and a force platform, respectively. The data are input into a three-dimensional model of the lower trans-tibial extremity and the corresponding muscle forces are predicted by a static optimization process. Muscles perform much more actively in stance than in swing phase. Most muscles appear very active around both heel-strike and toe-off. The bigger joint moments increased muscle forces. Muscle forces get weak because the joint moments reduced rapidly and look almost the same in later stance and swing phase. In addition, most flexors keep a little acting according to little joint moments exerted to prevent hyperextension.