Involuntary twitching of thigh muscles is mainly seen in the following three clinical situations: first, lumbar disc herniation compresses the nerves, causing twitching or pain in the thigh muscles. If the muscle pain is on the front side of the thigh, then it is usually a lumbar three or four disc herniation; if the muscle twitching is on the outside of the thigh or the back side of the thigh, then it is likely to be a lumbar four or five or a lumbar five sacral disc herniation. The second kind, after prolonged walking or strenuous exercise, muscle damage and inflammation of the fascia in the thigh area, and involuntary throbbing or twitching of the thigh muscles may occur when resting in bed or when walking. The third type, because of calcium deficiency, such as lower blood calcium can lead to throbbing pain or cramps in the muscles of the thigh area, also known as cramps.