Bone spurs can develop on almost any bone, including the heel, and sometimes produce pain and other symptoms. Two painful heel conditions are associated with the formation of bone spurs:
- Heel spur syndrome involves the formation of a bone spur at the bottom of the heel, on the sole of the foot. People who have a common foot condition called plantar fasciitis can develop these spurs, which are often referred to as heel spurs or calcaneal spurs.
- Insertional Achilles tendonitis can be associated with bone spurs at the back of the heel, where the Achilles tendon inserts into the bone.
Bone spurs that develop with plantar fasciitis or Achilles tendonitis are sometimes called by their medical name, enthesophytes.
Bone spurs are common, and the likelihood of developing them increases with age.1
Heel Spur Syndrome
Heel spur syndrome is a condition associated with heel spurs, bony protrusions that grow on the bottom of the heel. A heel spur forms where the plantar fascia—band of fibrous tissue stretching along the bottom of the foot—connects to the heel bone. The spur grows in the direction of the plantar fascia and often forms a hook-like shape.
Heel spurs develop as a bone’s response to stress from:
- Straining foot muscles and ligaments
- Over-stretching the plantar fascia
- Repeated tearing of the thin lining of the heel bone
There is good news as it relates to these heel spurs. The vast majority of heel spurs usually do not cause pain. In fact, only 5% of people with heel spurs have foot pain.2 Heel spurs often occur in athletes participating in sports involving running and jumping. They are also associated with age, obesity, and osteoarthritis.
Insertional Achilles Tendonitis
Insertional Achilles tendonitis affects the back of the heel, where the Achilles tendon inserts into the heel bone. The bone spur gradually develops around the tendon where it inserts into (attaches to) the bone.
The bone spur can irritate the Achilles tendon, potentially causing more tendon damage and pain. In addition, the inflamed and/or damaged portion of the Achilles tendon can calcify, or harden.
Insertional Achilles tendonitis is associated with decreased ankle range of motion and increasing age—people who are affected are often in their 40s, 50s, or 60s.3 Achilles tendonitis usually develops gradually and is not linked with a single incident or trauma. Jumping and running can exacerbate this condition, along with negotiating stairs, making inflammation and heel pain worse.
Insertional Achilles tendonitis is different than non-insertional Achilles tendonitis, which causes pain in the lower calf, where the Achilles tendon and calf muscle meet.