The muscle soreness of the buttocks and calves may be caused by the following reasons: 1. It may be caused by overexertion, such as long-distance running or activities like frog jumping or squatting, which may cause a large amount of lactic acid deposition inside the muscles of the buttocks and calves, and then cause soreness. 2, The pain may be caused by traumatic injury, such as direct violent impact in a car accident, or pulling or twisting injury. 4. 5, there may also be peripheral neuropathy, such as sciatica or lumbar disc herniation, can cause the above two parts of the pain at the same time.