Depression at the base of the thighs may be a symptom of limited scleroderma, muscle atrophy, trauma and other factors, the patient should consult a doctor in time to clarify the diagnosis. 1. Limited scleroderma: limited scleroderma, also known as scleroderma, is a kind of dermatologic disease in which the skin is swollen and gradually hardens and atrophies. It occurs on the scalp, limbs, forehead and other parts of the body. Patients may initially have a reddish, slightly edematous rash, which gradually hardens to a yellowish color with a slightly concave center, and in the late stage, it may manifest as skin atrophy. Therefore, patients with limited scleroderma may have the symptom of depression at the root of thighs. 2. Muscle atrophy: myotonic dystrophy, lumbar spine disease, muscle metabolic disease, etc. can lead to the damage of femoral adductor muscle fibers, which will lead to the symptoms of narrowing of muscle circumference and muscle atrophy. Therefore, muscle atrophy will lead to the symptoms of thigh root depression. 3. Trauma: when the patient’s quadriceps muscle suffers a violent external blow, it will lead to local extensive hematoma, muscle fiber rupture, and then the symptoms of thigh root depression. Patients with indentation at the root of the thigh should go to the hospital in time and under the guidance of the doctor for regular treatment.