Soreness in the lower part of the buttocks and the back of the thighs, first of all, it is considered to be caused by over-exertion, at this time, pay more attention to rest, sleep on a hard board bed. Secondly, consider the local compression caused by, such as sleep has been to maintain a position, or a long time to repeat a movement caused by. To pay attention to the activities of the limbs, to avoid local compression, you can use a hot towel on the back of the thigh for hot compresses. If the pain is severe, you can also take diclofenac and other drugs with anti-inflammatory and analgesic effects, and you can also use ethopiridone hydrochloride and other drugs to treat muscle spasm. Finally, sodium bicarbonate can also be taken to improve the local acidic environment. In addition to this, it is necessary to consider pathological causes, such as lumbar disc herniation, femoral head necrosis, rheumatoid arthritis, etc., and it is necessary to go to the hospital for further clear diagnosis.