The possible causes of soreness of the lateral thigh muscles include acute muscle strain, leg muscle strain, and lumbar disc herniation. 1. Acute muscle strain: it may be due to strenuous exercise, resulting in injury to the lateral thigh muscle or strain of the broad fascia tensor muscle, manifested as soreness of the lateral thigh muscle. 2. Leg muscle strain: it may be caused by overloaded sports or prolonged physical activities, such as frequent mountaineering, etc., which may easily cause thigh muscle strain, manifested as soreness of the lateral thigh muscles. 3. Lumbar disc herniation: it may be lumbar disc herniation, resulting in nerve root compression, causing radiating pain in the lower limbs, and symptoms of lateral thigh muscle pain. Lateral thigh muscle pain may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.