Butt pain when walking after leg rehabilitation may be related to lumbar disc herniation, hip arthritis, sacroiliac arthritis and other factors. 1. Herniated lumbar disc: Herniated lumbar disc compresses the nerve root innervating the hip area, which can cause the symptom of buttock pain. 2. Hip arthritis: in the early stage of hip arthritis, there may be hidden pain and discomfort after activity, with intermittent attacks. 3. Sacroiliac arthritis: when suffering from sacroiliac arthritis, the pain can also extend to the buttocks, crotch and upper third of the thighs, which can be induced by exercise, weight bearing and other factors. It is recommended that those who have pain in the buttocks when walking after leg rehabilitation go to a regular hospital in time to clarify the cause of the disease and carry out standardized treatment under the guidance of the doctor, so as not to delay the condition.