Thigh muscle throbbing may be caused by strenuous exercise, high mental tension, pyriformis syndrome, lumbar disc herniation and other reasons. 1. Strenuous exercise: after strenuous exercise, the thigh muscles will produce normal spasmodic reaction, the muscles will have a strong contraction, or even twitching, which will cause thigh muscle throbbing. 2. High mental tension: If there is high mental tension such as high mental stress, excessive excitement, or great fear, it will lead to a significant increase in the excitability of its nervous system, and the phenomenon of thigh muscle throbbing may occur. 3. Piriformis syndrome: it may be caused by piriformis syndrome, when the sciatic nerve is compressed by the edema of the piriformis muscle, it will lead to twitching and throbbing of the muscles of the back side of the thigh, and even pain and numbness. 4. Lumbar disc herniation: Lumbar disc herniation may lead to nerve root compression, so that the nerve conduction is impaired, causing thigh muscle throbbing and even numbness and weakness. If the thigh muscle throbbing phenomenon has not been relieved, you should go to the hospital in time and ask the doctor to make a clear diagnosis and treatment.