Plantar fasciitis: Inflammation of the plantar fascia (fasciitis), the "bowstring-like" tissue in the sole of the foot stretching from the heel to the front of the foot.

Plantar fasciitis (and heel spurs) may occur alone or be related to underlying diseases which cause arthritis (inflammation of the joints) such as Reiter's disease, ankylosing spondylitis, and diffuse idiopathic skeletal hyperostosis.

Plantar fasciitis is often associated with a bony spur projecting from the underside of the heel that makes walking painful. Spurs under the sole (plantar area) typically cause localized tenderness and pain that is made worse by stepping down on the heel.

Treatment is designed to decrease the inflammation and avoid reinjury and irritation of the inflamed tissues. Icing reduces pain and inflammation. Antiinflammatory agents (such as ibuprofen or injections of cortisone) can help. Infrequently surgery is done on chronically inflamed spurs. A donut- shaped shoe insert and cushioned footwear, such as running shoes, can take pressure off the plantar spur and lessen the plantar fasciitis.