Rear buttock muscle generally refers to the hip muscle, bone necrosis generally refers to the femoral head necrosis, rear buttock muscle pain is not necessarily femoral head necrosis. Necrosis of the femoral head is mainly manifested as pain and soreness in the hip or groin area. The common causes of hip muscle pain are caused by factors such as exertion, trauma, lumbar spine disease, and pyriformis syndrome. 1. Exertion: due to strenuous exercise leads to muscle anaerobic metabolism, so that lactic acid accumulation in the muscle, resulting in the phenomenon of buttock muscle pain, which is a normal physiological phenomenon, generally do not need treatment, after rest can be adjusted on their own. 2. Trauma: trauma due to impact, fall and other traumatic injuries can cause pain in the buttock muscles, mild cases can be gradually relieved by appropriate rest, while severe cases should be promptly hospitalized and examined. 3. Lumbar spine disease: lumbar spine osteophytes, herniated disc and other diseases, due to lumbar spinal stenosis leading to nerve root compression, buttock muscle pain, lower limb pain and numbness and other symptoms. 4. Pearly muscle syndrome: mainly by the pear-shaped muscle region of the sciatic nerve is stuck pressure, can cause buttock muscle pain. When the rear buttock muscle pain to exclude physiological factors, should promptly go to the hospital, identify the cause of targeted treatment.