The unshod runners' style causes more flex in the foot's springlike arch ankle and knee and engages more foot and calf muscles blunting the impact on the body and making for a more comfortable "ride."

The overstretched knee ligaments and tendons are also usually accompanied by changes in adjacent muscle groups, including the soleus muscle, which is deep in the calf.

Methods By using the reverse anterolateral femoral skin and muscle flap transposed transplantation to repair serious soft tissue defect of the knee and upper calf.