Thighs have a tendon squatting down on the pain, the most likely cause of two: First, lumbar disc herniation or lumbar disc bulging disease, lumbar disc herniation or bulging disease, squatting will lead to increased abdominal pressure, the disc protrudes backward more serious, stimulate the corresponding segment of the nerve root will cause thigh or lower limb obvious radiating pain; Second, there is a maximum possibility is the thigh of the local ligamentous strain, the thigh of the muscle, ligamentous strain will appear more obvious pain after activity, the ligament will be stretched more obvious when squatting, so the pain is also more obvious. Thigh muscle, ligament strain will appear more obvious after the activity of the pain, in the squatting ligament will be stretched more obvious, so the pain is also more obvious. However, the specific cause of which, must go to the hospital to find a specialist for a detailed examination and further auxiliary examination, to clarify the diagnosis and further treatment.