There are many reasons for the depression on both sides of the thigh, such as old injury, long-term pressure, muscle atrophy and so on. 1. Old injury: if there is a large area of thigh, deeper soft tissue loss, or there is a more serious fracture of the femur phenomenon, due to old injury can lead to the phenomenon of depression on both sides of the thigh. 2. Long-term pressure: long-term compression of the thighs can also lead to the phenomenon of depression of the thighs, especially common in the bad posture of the crowd, such as stilt legs. 3. Muscle atrophy: thigh depression on both sides may be due to muscle atrophy, commonly caused by local nerve damage leading to muscle paralysis, or due to a long period of time lying in bed without movement. There are many reasons why the thighs are sunken on both sides, it is recommended to go to the hospital in time to improve the examination after the symptoms, under the guidance of the doctor to take standardized treatment, do not treat yourself, so as not to lead to adverse consequences.