There are several common reasons why your feet keep cramping. The first is lumbar disc herniation. After the lumbar disc herniation, backward compression of the surrounding nerve roots, and cause a series of neurological symptoms, the nerve is stimulated, it caused the muscle contraction twitching, driving the foot twitching. Second, the cause of the sciatic nerve. Sciatic nerve in the pearly fossa by the pearly fossa of the cardinal pressure, and cause a series of nerve symptoms. The nerve is stimulated to cause muscle twitching and contraction, driving the twitching and contraction of the foot. The third common reason is that after localized pulling, muscle twitching is caused by damage to the muscle itself.