What are the causes of heel spurs?

Tightness: When the achilles tendon or plantar fascia pulls on the heel, the heel responds by putting more bone down to protect itself from the pulling. Stretching the calf muscle and rolling stretch underneath the heel and arch should loosen the tightness.

Mechanical stress: Excessive motion or collapse of the foot causes tension where the plantar fascia or achilles' tendon meet the heel bone. The bone reacts by "growing more bone". The spur itself, is seldom painful and pain resolves when the stress is relieved and inflammation controlled.

Excess pull: Heel spurs are extra bone formed by pull of a ligament or tendon insertion at the calcaneus. Plantar heel spurs are due to a pull from the plantar fascial ligament and are sometimes, but not necessarily, associated with plantar fasciitis. Posterior calcaneal heel spurs are due to a pull from the Achilles tendon. Plantar fasciitis or equinus can cause heel spurs.