Mary
I believe my daughter had the same problem from walking on her toes - shortened tendons in the back of her heal. You can try exercising your tendon by placing your feet on a telephone book (front feet, on and back of feet, off) and lift feet up to book and back down to floor - to stretch out the tendons. The tendon in the back of the foot tends to hurt when you walk because it is not stretched out (especially when you sleep). Good luck and hope you feel better.