Drug injection injury, especially penicillin injection, is the most common cause of sciatic nerve injury, also known as medical sciatic nerve injury, preferably in children, the cause of the injury and the injection site improper direct injury or too large a dose of drugs to stimulate the sciatic nerve; sharp instrument injuries, acetabular fracture, pelvic fracture, and dislocation of the hip joint, especially the posterior dislocation is also a common cause of sciatic nerve injury. 1, sports: if the injury site in the sciatic foramen magnum or above the sciatic tuberosity, then the posterior femoral muscle group, calf anterior, posterior and posterior muscle groups and foot muscles are all paralyzed. If the injury is in the middle and lower part of the femur, because the popliteus muscle branch has been largely issued, only the muscles below the knee are all paralyzed. If the branch is injured, the muscles in the innervation area of common peroneal nerve and tibial nerve are paralyzed. Sensory aspect: Except for the saphenous nerve innervation area at the inner side of the calf and the inner ankle, the sensation in the area below the knee is lost. 3.Nutritional aspect: there are often severe nutritional changes, and the soles of the feet often have deeper ulcers. History of trauma or injections, paralysis of muscles below the thigh or below the knee; paralysis of muscles in the innervated area of nerve branches. Partial sensory loss in the area below the calf. Electromyography confirms the diagnosis.