A heel spur is a bony protrusion comprised of calcium that develops on the bottom of the heel bone. The calcium deposit builds up typically because of stretching and general overuse of the foot muscles and ligaments, which can lead to overstretching of the planta fascia and tearing of the membrane covering the heel bone.
Usually a heel spur has no symptoms and is not painful, although among athletes, especially runners, it can cause some discomfort. The build-up of calcium and any possible pain usually develops over a significant period of time, as the soft tissue around the spur becomes inflamed. Usually pain due to a heel spur is directly related to Plantar Fasciitis, inflammation of the connective tissue running along the bottom of the foot.
Those engaged in activities that involve a lot of running and jumping are most susceptible to heel spurs, as these activities put the most strain on the muscles and ligaments on the bottom of the feet. Running on hard surfaces, or running and jumping in poorly fitting footwear, can lead to heel spurs.
Training with proper technique and properly fitted shoes, as well as keeping weight at a healthy level, can all help prevent heel spurs and other painful foot conditions.