Most of the inability to squat after a patella fracture is due to the lack of rehabilitation exercises after the fracture has healed. 1. Rehabilitation exercise after fracture injury is crucial to the recovery of body function, if not carried out step by step rehabilitation exercise, may cause disuse syndrome. Most of the patellar fracture can not squat is also due to the recovery period did not carry out reasonable rehabilitation exercise. 2. Early functional exercise of the knee joint requires active and passive squatting, flexion and extension activities. Can prevent the knee joint muscle atrophy and functional ankylosis, restore the functional activities of the knee, and vice versa will affect the squatting function of the lower limb. If the patella fracture is well can not squat there may also exist other reasons, it is recommended to consult the doctor, under the guidance of the doctor to find the cause or rehabilitation exercises.