Cushion versus Support for Heel Pain

Plantar heel pain is a frequent cause of disability and referral to physical therapy. A recent clinical practice guideline by Martin and colleagues (2014) identified ‘A’ level evidence that foot orthoses can reduce symptoms and improve function associated with plantar heel pain.⁵ Prefabricated (also, off-the-shelf or over-the-counter) devices have been shown to work similarly to custom devices.³ Some studies involved semi-rigid devices⁴, while other studies involved cushioned devices², and another study used a combination of both!¹

The evidence is pretty sparse with regard to how and why different orthotic devices work. This situation requires us to “color in around the edges” with clinical reasoning related to orthotic construction. With so many different kinds of orthotic devices to choose from, how can we counsel our patients to make the right choices? Here are some ideas to guide our clinical reasoning about whether to ‘cushion’ or ‘support’ with orthotic management in patients with plantar heel pain.

The Case for Cushion: Compression Sensitive Structures

Some structures of the foot and ankle are compression sensitive. The chief example of a compression-sensitive structure associated with heel pain is the plantar heel fat pad. It compresses at heel strike and attenuates shock. The plantar heel fat pad is also innervated and vascularized.⁶ Unfortunately, it can degenerate over time or in response to repetitive corticosteroid injections aimed to alleviate pain associated with other heel structures. Pain related to plantar heel fat pad involvement, otherwise known as heel stones or heel bruises, can be very debilitating and recalcitrant to treatment. Neurogenic heel pain combined with limited sensation, such as diabetic polyneuropathy, may also require careful management of compressive loads across the plantar foot to prevent ulceration.

A cushioned orthotic device can help compression-sensitive structures manage compressive loads. If the plantar heel pain is associated with pain during palpation of the plantar heel fat pad, a soft foam or gel device placed under the plantar heel may reduce cumulative tissue compression associated with repetitive heel strikes while walking and running. These types of soft devices tend to wear out quickly, so advise patients to inspect and change them frequently.

There are taping techniques to offload the plantar heel fat pad too. If plantar foot sensation is intact, consider trying taping first in order to assess whether a cushioned orthotic device might be a good intermediate- or long-term solution.

The Case for Support: Traction-Sensitive Structures

Some foot and ankle structures are traction-sensitive. The plantar fascia (aponeurosis) is a good example of this type of structure. During the stance phase of gait, the plantar fascia is placed on tension when the foot pronates (early to mid-stance) and when the first metatarsophalangeal joint dorsiflexes (late mid-stance, terminal stance, and pre-swing). If these movements are excessive, or loading is excessive during normal movement, over time the corresponding cumulative tension on the plantar fascia could eventually result in plantar fasciitis/fasciopathy.

A supportive orthotic device aims to provide support to the arch of the foot by controlling the amount and/or rate of arch deformation during normal foot pronation. If the arch pain originates with the plantar fascia or other traction sensitive structure, a supportive device might be helpful. Try taping the arch first to see if investing in a device might provide a long-term solution. A favorable short-term response to arch taping might suggest a favorable response to semi-rigid orthotic devices, as well.

Two Starting Points

With these two starting points, we should be able to paint the fuller pathoanatomic picture of a patient’s plantar heel pain, decide on an intervention that can result in immediate- and short-term pain relief, and generate patient buy-in to a comprehensive treatment plan.