fossa tendon pain at the back of the leg, different causes of pain at the back of the leg, the treatment is different, if it is a popliteal cyst, surgery can be performed, if it is a strain on the hamstring muscle, sports should be avoided, as follows: 1, popliteal cyst: mainly due to the leakage of joint fluid from the weakness of the joint capsule, the formation of a lump at the back of the knee joint, manifested as soreness, especially when walking more soreness will increase, and the lump The soreness and swelling will increase, especially when walking a lot, and the lump will increase in size. In this case, surgical treatment is recommended. At present, minimally invasive surgery can be performed to excise the cyst under the knee arthroscope, which can completely remove the cyst to prevent recurrence.2. Hamstring strain: Excessive sports, for example, or excessive stretching of the knee joint, can easily cause damage to the hamstring muscle. This requires avoiding sports for about 1-2 weeks, and can be treated symptomatically with conventional anti-inflammatory and pain-relieving drugs, and using local heat and physical therapy to relieve pain.