The back of the thigh tendon pain reasons are mainly the following: 1, the back of the thigh biceps femoris, semitendinosus, semimembranosus and other muscle tissues continue to fatigue, such as squatting for too long, resulting in these two muscles continue to be in a state of tension and fatigue, gradually will form a strain, produce inflammatory lesions, will stimulate the peripheral nerves around the location of pain. 2, because the muscles of the back of the thigh in not fully relaxed The pain in this position will also be obvious due to the strain on the back of the thigh, such as the hip joint and the thigh when the thigh is stretched with force, because the normal load of the muscle is exceeded, the muscle fibers will appear. Strain, in the local will produce bruising and inflammatory stimulation, will also appear pain.