Plantar fasciitis is inflammation, usually due to injury, of the plantar fascia, the ligament between the front of the heel bone and the base of the toes that helps to support the arch.

It causes severe pain on the bottoms of the feet, especially in the morning.

Excess stress absorbed by the foot may irritate or tear the plantar fascia, making this a common disorder among athletes, especially runners.

Plantar fasciitis can be caused by a tendency of the foot to roll inward (pronation) upon walking.