The plantar fascia consists of a medial, central, and lateral segment. The fascia is often referred to as an aponeurosis. Magnetic resonance imaging (MRI) studies of patients with heel pain often reveal abnormalities of only the central or intermediate portion of the fascia. Fasciitis is actually not an accurate description for the condition. Microscopic studies of the plantar fascia in patients with heel pain usually reveal disorganization of the collagen fibers, an increase in the number of fibroblasts, and a mucoid ground substance with minimal inflammation of the fascia. These abnormalities are similar to injuries involving the Achilles tendons, patellar tendons, and rotator cuff and are more properly called tendinoses.
Tendinosis is an overuse condition from degeneration rather than inflammation. Both MRI and ultrasound confirm thickening of the fascia in symptomatic patients. The plantar fascia is 2-4 mm in asymptomatic patients, while it is 6- to 10-mm thick in patients experiencing heel pain.[3,4] Consequently, "heel pain syndrome" has been suggested as a more appropriate term than plantar fasciitis because there is no evidence of inflammation.
Microtears of the collagen fibers are thought to be the cause of the microscopic changes. It seems that heel impact does not cause the pathologic changes in patients with heel pain syndromes. Specifically, gait studies performed on patients with heel pain demonstrate no difference in the force of the heel strike in affected and unaffected heels. X-rays of patients with heel pain sometimes reveal a calcification of the plantar aponeurosis at the origin on the calcaneus, commonly referred to as a heel spur. The heel spur represents a marker for chronic heel pain but is not the cause of the pain. In fact, foot x-rays of patients often reveal spurs in patients who are asymptomatic. In addition, the presence or absence of a spur does not change the response to therapy.
American Academy of Emergency Medicine © 2007 American Academy of Emergency Medicine
Cite this: Plantar Fasciitis: Evidence-Based Management - Medscape - Oct 11, 2007.