The function of the heel in walking is to absorb the shock of your foot striking the ground as it is put down and to start springing you forward on the next step. It contains a strong bone (the calcaneum). Under the bone are a large number of small pockets of fat in strong elastic linings, which absorb much of the shock (fat pads). The heel is attached to the front of the foot by a number of strong ligaments which run between the front part of the calcaneum and various other parts of the foot. The strongest ligament is the plantar fascia, which attaches the heel to the toes and helps to balance the various parts of the foot as you walk. It therefore takes a lot of stress as you walk.