By Erick Janisse, C.Ped., CO

Heel pain is one of the most common sources of a certified pedorthist’s referrals. Treating heel pain is often simple. But occasionally it can be frustrating.

Many of the frustrating, lingering heel pain cases can be traced back to one of two things: improper treatment or a misdiagnosis. Understanding plantar fasciitis—heel pain’s most common cause—and its differential diagnoses will help C.Peds achieve a consistently higher success rate when dealing with the inevitable heel pain patient.

Defining plantar fasciitis
“Definitely most of the heel pain I see is plantar fasciitis,” says Patti Gottsacker, PT, C.Ped., of National Pedorthic Services in Milwaukee, Wis.

“When a patient has been diagnosed with plantar fasciitis,” she says, “it is important to understand that even though the pain is in his or her heel, it is really a whole-foot problem. The plantar fascia runs from the heel to the ball of the foot and gets strained with every step. Where the patient feels the pain is at the point where the fascia attaches to the calcaneus. That is why supporting the arch with an orthosis works so well.”

Orthotic treatment of plantar fasciitis typically consists of a custom foot orthosis with good medial longitudinal arch support and cushioning in the heel. An often overlooked but effective tool in treating plantar fasciitis is the use of a carbon fiber footplate in addition to the orthosis.

When the toes are dorsiflexed, the plantar fascia is stretched taut. This is known as the Windlass mechanism. It increases stress on the calcaneal insertion site of the plantar fascia. Using a carbon fiber plate decreases toe dorsiflexion, and, in turn, reduces stress on the plantar fascia.

When it’s not the obvious
Plantar fasciitis is the most common cause of heel pain, but what about those patients without a clear and specific diagnosis?

Gottsacker says she gets many prescriptions written with only the vague diagnosis of “heel pain.” She also adds, “I do get people who don’t respond well to the typical plantar fasciitis treatment regimen of foot orthoses, night splints and an Achilles stretching program and I start to wonder if there isn’t something else going on.”

There are several other conditions that cause pain in the heel area and may even mimic plantar fasciitis’ symptoms.

Central heel pain syndrome
One condition is commonly referred to as central heel pain syndrome. In plantar fasciitis, the pain is located in the medial plantar aspect of the heel. A patient with central heel pain syndrome complains of pain directly under the center of the calcaneus.

A foot orthosis may be used to treat this problem, but a better solution is a thin thermoplastic heel cup that will fit snugly on the heel and help to contain the plantar fat pad under the calcaneus.

Calcaneal fracture
Some patients who come to a physician’s office complaining of heel pain will have a calcaneal fracture. After all, the calcaneus is the most commonly fractured tarsal bone. A calcaneal fracture will be painful when the calcaneus is squeezed from the sides.

A calcaneal fracture can be treated [by the doctor] with a cast or surgical intervention. Pedorthic care for a healed or healing calcaneal fracture has traditionally been a simple foot orthosis and a shoe with a rocker sole. With advances in viscoelastic polymers, a pedorthist can now provide an orthosis with a thick layer of polymer under the heel to attenuate shock on heel strike.

Tarsal tunnel syndrome
According to Dr. John P. Metzler, a physiatrist with Washington University School of Medicine’s Department of Orthopaedics in St. Louis, tarsal tunnel syndrome is a common source of heel pain, but one of the least correctly diagnosed. “In my practice, tarsal tunnel syndrome is probably the second most common type of heel pain that I treat.”

Tarsal tunnel syndrome occurs when the posterior tibial nerve gets inflamed, impinged or compressed as it passes through the fibro-osseus tunnel formed by the calcaneus and the lacinate ligament.

There are multiple causes of tarsal tunnel syndrome. It can be due to the position of the foot as a result of the nerve being placed in traction by a planovalgus foot. It can also be due to tight ligaments.

“The diagnosis is a challenging one,” says Metzler. “The symptoms are sometimes vague. The patient may have activity-related pain, or pain at rest. Paresthesias, burning and shooting pains that follow the nerve’s distribution are part of a typical story.

“We use an EMG [electromyography] and nerve conduction study to help make the diagnosis. This is where it gets tricky,” he says. “A positive EMG and nerve conduction study is conclusive, but a negative one doesn’t necessarily rule out tarsal tunnel syndrome.

“It is by far one of the most frequently misdiagnosed conditions. It is often misdiagnosed as something else, but time and time again when doctors don’t know what is causing the heel pain they incorrectly chalk it up to tarsal tunnel syndrome.”

“Tarsal tunnel syndrome can be treated surgically by either releasing or resecting the nerve, but it’s definitely worthwhile to try pedorthic treatment first.” But Metzler warns, “Keep in mind that because you’re dealing with a nerve, orthotic treatment can be very hit-or-miss.”

When the tarsal tunnel syndrome is secondary to a planovalgus foot deformity, try using a foot orthosis to correct the foot position so that the stress and strain on the nerve will be reduced, in turn reducing the compression. The problem is that the area around the nerve route can be hypersensitive and the patient will not tolerate a rigid arch pressing up against it.

One way around this dilemma is to create a custom, multi-density, semi-rigid foot orthosis that supports the arch and conforms closely to the foot. Once this has been fabricated and the fit has been confirmed, remove a channel of base material along the tender nerve route and fill it with a low-density viscoelastic polymer. Keep the top cover wholly intact so as not to disrupt the intimate interface between the foot and the orthosis.

With this innovation, the orthosis provides good arch support as well as support around the heel—adequate to correct the planovalgus alignment of the foot—without placing excessive pressure on the inflamed nerve.

Ask for clarification
As with anything in pedorthics, orthotics or prosthetics, it is paramount not to pigeonhole patients. Assuming everyone with heel pain has plantar fasciitis and treating them as such is sure to cause headaches.

Never be afraid to contact the physician for clarification on a prescription that reads simply “heel pain.” You and your patients will both benefit from having a clear understanding of the root cause of their pain.  

Erick Janisse is the facility manager at National Pedorthic Services in St. Louis, Missouri.