The classic presentation of plantar fascitis is “a sharp heel pain that radiates along the bottom of the inside of the foot. The pain is often worse when getting out of bed in the morning.”1 This can occur in runners or other athletes who repetitively land on the foot. Another susceptible group is middle-aged persons who have spent much time on their feet. More rarely, the fascia becomes inflamed after a single traumatic event, such as landing wrong after a jump, or running a long hill.
The vast majority (95%) will respond to conservative care, and not require surgery.2 Proper treatment is necessary, however, to both ensure continued participation in sports and daily activities and avoid chronic damage. The plantar fascia is the major structure that supports and maintains the arched alignment of the foot.3 This aponeurosis functions as a “bowstring” to hold up the longitudinal arch.
Plantar fascitis develops when repetitive weight bearing stress irritates and inflames the tough connective tissues along the bottom of the foot. High levels of strain stimulate the aponeurosis to try to heal and strengthen. If the biomechanical strain continues, it overwhelms the body’s repair capacity, and the ligaments begin to fail. It is this tear/repair process that causes the chronic, variable symptoms that can eventually become unbearable in some patients.
Since the plantar fascia inserts into the base of the calcaneus, the chronic pull and inflammation can stimulate the deposition of calcium, resulting in a classic heel spur seen on a lateral radiograph. Unfortunately, there is no correlation between the presence of a heel spur and plantar fascitis; many heel spurs are clinically silent, and most cases of plantar fascitis do not demonstrate a calcaneal spur.4
Biomechanical evaluation may find either excessive pronation or supination. The flatter, hyperpronating foot overstretches the bowstring function of the plantar fascia, while the high-arched, rigid foot places excessive tension on the plantar aponeurosis. In either case, it is the combination of improper foot biomechanics and excessive strain that causes the connective tissue to become inflamed. A careful assessment of the weight bearing alignment of the lower extremities is helpful, since many patients will have functional imbalances up the kinetic chain, into the pelvis and spine.
Direct palpation of the plantar fascia will demonstrate discrete painful areas, most commonly at the insertion on the antero-medial calcaneus.5 Fibrotic thickenings are frequently felt—these are remnants of the repetitive “tear and repair” process. With the foot relaxed, grasp the toes and gently pull them up into passive dorsiflexion. Since this maneuver stretches the irritated plantar aponeurosis, it is frequently quite painful, and is an obviously positive objective sign.
Plantar fascitis usually responds well to focused, conservative treatment. Steroid injections and surgical release are seldom necessary, and are best avoided. One of the most important treatment methods is to reduce any tendency to pronate excessively. In addition to custom-made orthotics, runners should wear well-designed shoes that provide good heel stability.
The use of custom-made orthotics can prevent many overuse problems from developing in the lower extremities. Investigation of foot biomechanics is a good idea in all patients, but especially for those who are recreationally active.
Dr. John J. Danchik is the seventh inductee to the American Chiropractic Association Sports Hall of Fame. He is the current chairperson of the United States Olympic Committee’s Chiropractic Selection Program. He lectures extensively in the United States and abroad on current trends in sports chiropractic and rehabilitation. Dr. Danchik is an associate editor of the Journal of the Neuromusculoskeletal System. He has been in private practice in Massachusetts for 27 years. He can be reached by e-mail at [email protected].