For patients with pain in the back of the thigh, it can be seen in the following aspects: First, it is seen in the muscle pulling injury of the back of the thigh, which is mostly seen in the activities of strenuous running and jumping, squatting and climbing, which can easily lead to excessive force and pulling of the muscles of the back of the thigh, thus causing obvious pain in the back of the thigh. Second, seen in the posterior thigh fasciitis, this condition is also related to strain, cold, but this strain is often a long time of force, friction caused by no obvious trauma and history of strenuous activities, and cause pain in the posterior thigh. Third, the innervating nerve of the muscle of the back of the thigh is compressed, mostly seen in the pyriformis syndrome, thus compressing the sciatic nerve, which will cause the muscle of the back of the thigh to lose innervation, causing pain in the back of the thigh.