Symptoms of localized muscle depression in the buttocks may be caused by physiological factors such as prolonged sitting or lack of exercise, or by pathological factors such as lumbar intervertebral disc herniation, sciatic nerve injury, and femoral head necrosis. 1. Physiological factors: prolonged sitting or lack of exercise can lead to atrophy of the muscles on both sides of the buttocks, thus causing local muscle atrophy. It is also possible that insufficient protein intake may lead to insufficient nutrition of the muscles, resulting in muscle dysplasia and lack of elasticity, which in turn may cause the symptoms of buttock muscle depression. 2. Pathological factors (1) Herniated lumbar intervertebral disc: The structural change of lumbar intervertebral disc and the protrusion of nucleus pulposus to the side of the annulus fibrosus will compress the surrounding sciatic nerve, thus leading to muscular dystrophy in the area innervated by the sciatic nerve. If left untreated for a long time it will lead to muscle atrophy and muscle depression. (2) Sciatic nerve injury: Incorrect posture or excessive pulling by external forces can lead to damage to the sciatic nerve and inflammation, thus affecting muscle contraction and resulting in muscle depression. (3) Necrosis of the femoral head: Necrosis of the femoral head can also lead to atrophy of the muscles on both sides of the buttocks, resulting in a sunken state. If the symptoms of hip muscle depression appear, it is recommended to go to the hospital as soon as possible to get a clear diagnosis.