Soreness at the outer thigh root, the specific causes are as follows: first, rotor bursitis: the outer thigh root is the rotor region, if often sleeping in the side position, it will lead to the rotor bursa being compressed, therefore, there will be bursal hyperplasia and inflammation of the rotor bursa, which is mainly manifested in the outer thigh rotor region of the pain. Second, crossing legs: may be due to a long time stilt legs, thigh inward, the rotator bursa will appear high tension state, over time will also appear bursa inflammation, thigh pain on the outer side of the thigh. Third, muscle injury: lateral thigh pain can be seen in the lateral muscle group injury, such as the broad fascia tensor muscle strain, there can be pelvic lateral thigh lateral soreness, pain, accompanied by thigh abduction function is limited.