Calf muscle wastage in people with partial foot amputation wearing footwear with fillers

Some people with partial foot amputation have shown calf muscle wastage after using fillers inside their footwear. This research aimed to investigate effects of fillers and footwear on individual calf muscle forces while walking at preferred speed. Gait data of two subjects with partial foot amputation and a healthy subject was used. For each subject, a musculoskeletal model was developed using a suitable generic model. Adapted experimental gait data was used, gait was simulated, inverse kinematics, inverse dynamics and static optimization tools were used to decompose the ankle joint moment between the calf muscle-tendon units by minimization the sum squares of all muscles’ activation. Only the subject with transmetatarsal amputation demonstrated substantial reduction in the calf muscle forces during stance, suggesting footwear with fillers may contribute in developing muscle wastage of calf muscles and different type of prosthesis may prevent the residual limb from developing calf muscle wastage.