Introduction
Plantar fasciitis (PF) is the most common cause of chronic heel pain and is a major health issue in runners and long-distance walkers. Overuse injury may lead to repetitive micro-tears of the plantar fascia near the calcaneus, irritating pain fibers and producing secondary inflammation. Other risk factors include obesity, flat or over arched feet, and improper shoes. The pain usually involves the inferior and medial aspect of the heel (calcaneus), at the medial aspect of the calcaneal tubercle. However, the entire course of the plantar fascia may be involved (Barrett & O'Malley, 1999). Patients describe pain variably as aching, jabbing or burning. In many patients, the application of ice and/or use of heel cup orthosis activity modification and a stretching/strengthening exercise program reduces the pain satisfactorily. Further measures include deep-tissue massage therapy, night splints, and periods of immobilization. Persistent cases may respond to treatment with posterior night splints, ultrasound, iontophoresis, phonophoresis, extracorporeal shock wave therapy (ECSWT), or even local corticosteroid injections (DeMaio et al., 1993). In cases of medical failures, surgery is advocated, with modest results. Approximately 10–12% of the patients fail to achieve pain relief from medical and/or surgical treatment.
Anatomy of the plantar fascia
The plantar fascia is composed of dense collagen fibers that extend longitudinally from the calcaneus to the base of each proximal phalanx (Figure 21.1a). The fascia has medial, central, and lateral parts, underneath which the flexor digitorum brevis (FDB) and the abductor hallucis (AH) muscles reside (Figure 21.1b).