The reason for calcaneal spur is a permanent overloading of the foot mainly the big aponeurosis under the sole of foot. Trough the overloading arises repeated cracks in the sinew. The corpus stocks calcium there to repair the cracks of the sinew like at a broken bone. So arise the calcaneal spur after some time as a small excrescence at the heel. At about 10 % of the population you could found a calcaneal spur. Most time it isn´t painfully in the heel. The importance of the calcaneal spur in coherence with heel ache is totally overrated. The pain isn´t because of the calcaneal spur but the inflammation of the micro cracks is very painfully at the insertion of the muscles and sinews. To avoid these overloading it should be wore soft and comfortable shoes.