The irritation is the result of biomechanical deformities such as limb length discrepancy, gastrocsoleus equinus, and excessive foot or leg varus, producing midtarsal and subtalar hyperpronation. In turn, this pronation produces a stretch of the plantar fascia as well as unwanted pulling on the origin of the fascia (the medial calcaneal tubercle).
The classic history of plantar fasciitis is marked by the insidious onset of sharp pain at the fascial insertion of the plantar surface of the anteromedial calcaneus. With these patients, you’ll note arch fatigue and generalized soreness on the sole of the foot. The patients will usually tell you that the pain is more severe when they get up in the morning and eases some after walking. You’ll also commonly hear that pain decreases during the middle of a run, but returns at the end of the day.
Upon palpation, you’ll typically detect heel tenderness anteromedially at the origin of the plantar fascia on the medial calcaneal tubercle. However, keep in mind that the patient may have pain along the entire length of the plantar fascia. If you note tenderness over the distal and midportion of the plantar fascia, your patient may have the less common distal fasciitis. If the entire heel is tender, it may be a stress fracture, calcaneal apophysitis (Sever’s disease) in a child, or possibly a bone tumor.
Although plantar fasciitis treatment often includes nonsteroidal oral medication, local steroid injections, ice after the run, ultrasound and stretching exercises, your main focus should be on treating the biomechanical imbalance. Employing orthotic devices can play a key role in this endeavor.
When You Should Use Heel Pads And Cushions
The first line of relief for treating plantar fasciitis, heel cushions provide extra shock absorption in the heel area. They help absorb the shock of heel strike in walking and running. Heel pads are generally constructed of polyvinyl chloride, silicone, leather, polyethylene foams like Plastizote, and thermoplastics.
Soft heel cups cushion and contain the fat pad. They are effective for a plantar calcaneal bursitis or plantar heel spur syndrome. When you’re treating patients who have heel pain as a result of fat pad atrophy, employing hard plastic heel cups (M-F Athletic, Cranston, RI) can sometimes be effective in positioning the heel pad underneath the calcaneus, restoring the natural cushioning and compressibility.
You may also consider the Anti-Shox heel cradle (Apex, South Hackensack, N.J.), which is made from a firm, open cell polymer. Designed to cup the heel, this orthotic provides both shock absorption and support. Another option is the SofSpot Viscoheel (Bauerfeind, Germany). This silicone heel cushion has a built-in area of softer durometer that is especially designed to disperse weight around the plantar medial tubercle of the calcaneus.
Sometimes, using a heel lift is helpful in shifting pressure to the forefoot. Keep in mind that a heel lift in the shoe should be no thicker than one-quarter inch.
An Overview Of Custom And Prefabricated Foot Orthoses
There are a variety of orthotic devices that you can use inside the shoe to provide support, increase shock absorption or influence foot position. Orthoses include dynamic insoles, heel cushions, prefabricated commercial foot orthoses and custom foot orthoses. Using an orthosis can help you reduce arch strain associated with plantar fasciitis.
When it comes to dynamic insole orthoses, you can construct them from Spenco (Spenco Medical Corp., Waco, TX), which is a closed-cell neoprene impregnated with nitrogen bubbles.
Prefabricated foot orthoses are commercially available in a wide variety of styles. Employing pre-made orthoses is adequate for treating many athletes with plantar fasciitis. They are also significantly less expensive than custom-made orthoses.
You can fabricate a custom-made orthosis from a negative plaster impression of the patient’s foot. The orthosis is composed of the shell, a layer of material next to the foot and the posting, the material that fills in the space between the shell and the shoe. You can add materials such as metatarsal pads to the device to customize it further.
Using a custom-made foot orthosis may be required when you’re treating a more severe athletic foot injury. Custom foot orthoses can be made of leather or plastic. Leather gives the patient more comfort, allows easy orthotic adjustments and is able to absorb 30 percent of its weight before it feels wet. You’ll find that using a whale pad design and deep heel seat leather orthosis is well suited for treating the painful heel caused by plantar fasciitis.
It’s more important to use a custom device for the cavus foot type as opposed to the hyper-pronated foot, which will generally improve with a well-constructed prefabricated orthosis.
Can The UCBL Orthosis Make An Impact?
The University of California Biomechanics Laboratory (UCBL) orthosis was originally designed to maintain a flexible paralytic valgus foot deformity in the corrected position. However, since then, DPMs have used it extensively to treat flexible flatfoot, plantar fasciitis and calcaneal spurs.
The UCBL is casted in a semi-weight-bearing position. Employing this device allows you to elevate the arch by holding the foot in a position of forefoot adduction and hindfoot inversion. Patients should wear it with a large shoe, such as a running sneaker. While the UCBL is not suited for running, you can use it to treat more recalcitrant conditions until the athlete is capable of returning to sports activities.
What About The Posterior Night Splint?
A classic treatment for Achilles tendinitis, the posterior night splint has been widely used by DPMs to treat plantar fasciitis as well. In one study, physicians were able to resolve recalcitrant plantar fasciitis with a night splint in 11 of 14 patients.
The splint is an ankle-foot orthosis (AFO) positioned in about 5 degrees of dorsiflexion. Patient would only wear this at night. In stretching the Achilles tendon and plantar fascia, this device prevents contractures of the Achilles tendon and plantar fascia that occur as a result of the plantar-flexed posture of the foot during sleep.
You can fabricate the posterior splint from plaster or fiberglass, or simply obtain the commercial device, Universal Plantar Fasciitis Orthosis (Orthomerica Products, CA). Regardless of the splint you use to immobilize the foot and ankle, you must ensure that it offers a good fit and maintains the desired position once you’ve applied the device.
In fabricating the splint, the patient lies prone as you initially place a stockinette on the leg. Then you would proceed to mold five to six layers of six-inch plaster splints (or three to four layers of fiberglass) to the lower extremity from the toes up to behind the knee. You should allow an extra two inches when measuring with the dry splints because the splint shrinks after immersion.
Then you can add overlapping side splint stirrups. Doing so adds strength to the cast and prevents it from failing in plantar flexion. Using a circular Ace bandage allows you to hold the entire splint in place. You can also dip the Ace bandage in water to help with molding.
References 1. Janisse DJ. Indications and Prescriptions for Orthoses in Sports. Orth Clin North Am 25:95-107, 1994. 2. Jimenez AL, Goecker RM. Night splints: conservative management of plantar fasciitis. Biomechanics 4:29, 1997. 3. Jorgensen U, Bojsen-Moller F. Shock absorbency of factors in the shoe-heel with special focus on the role of the heel pad. Foot Ankle 9:294, 1989. 4. Karr SD. Subcalcaneal heel pain. Orthop Clin North Am 25:161, 1994. 5. Pezzulo DJ. Using night splints in the treatment of plantar fasciitis in the athlete. J Sport Rehabil 2:287, 1993. 6. Pribut S. Leather as an orthotic material. Biomechanics 4:61, 1997. 7. Rzonca EC, Baylis WJ. Common sports injuries of the foot and leg. Clin Podiatr Med Surg 5(3), 1988. 8. Snook GA, Chrisman OD. The management of subcalcaneal pain. Clin Orthop 82:163, 1972. 9. Sobel E, Levitz SJ, Jones LS. Orthotic variants. J Am Podiatr Med Assoc 87:23,1997.