90% of time at night, tendons in top of foot at ankle area constrict in a most painful way and may also at times, involve the lower part of leg. These are not cramps. While the pain is intense, the tissue in the area remains norman. The muscles are not involved. Sometimes several times a night. But again it may not happen for 3 or 4 days..I have tried mildly exercising, different types of shoes..But nothing seems to make a difference. Would greatly appreciate anyones help on this...