Expert Insights On Casting And Prescribing Orthoses For Plantar Heel Pain

Nuanced casting techniques can aid podiatric physicians in providing the most effective orthoses for patients with plantar heel pain. These panelists discuss their preferred casting techniques, whether to modify the foot position during casting and the best footwear for orthoses for heel pain.  

Q:

What type of impression casting technique do you use for plantar heel pain? Plaster, foam box or scanner?  

A:

Doug Richie, DPM, FACFAS, still casts his orthoses for heel pain with plaster. In his experience, he has found that the original Root neutral suspension cast technique ensures the best position and correction of foot alignment to relieve stress on the plantar fascia.

Likewise, Brian Fullem, DPM, uses plaster for his custom devices. He uses the Light Orthotic system (Powerstep) for some patients.

In contrast, Bruce Williams, DPM, uses a digital scan of a foam box impression. He prefers a partial weightbearing scan but because he goes to several offices, the transportability of a large foot scanner is too cumbersome.

If the forefoot is everted to the end of range of motion, Dr. Richie says studies note this will relieve stress on the plantar fascia.¹ However, he cautions that the forefoot cannot pronate and evert to end range of motion with any type of weightbearing or semi-weightbearing scanning or foam box impression casting.

Q:

Do you modify foot position during the cast impression, specifically when treating plantar heel pain?  

A:

Whether Dr. Fullem will modify the patient’s foot position during casting depends more on foot type. He typically casts orthoses with the patient prone. Most often, Dr. Fullem will place patients in a subtalar neutral position and keep the forefoot perpendicular to the rearfoot.

“I understand that there are other methods that are considered better but this method seems to serve my patients well,” says Dr. Fullem, citing a “pretty high success rate” with his orthoses. “I do all my own casting as well. I feel the doctor should be the one casting.”

If the foot is inverted at the heel, Dr. Williams will often evert the foot position when casting. He will also evert those feet that are excessively pronated or in heel valgus to intrinsically post feet in a more varus or rectus heel position. Dr. Williams also tends to plantarflex the first ray in his casts. He does not dorsiflex or maximally pronate the lateral column as he uses a partial weightbearing cast. Instead, Dr. Williams will post the device with a lateral forefoot post to the amount of lateral forefoot excursion that is necessary according to his foot evaluation.

When Dr. Richie casts a patient for treatment of plantar heel pain, he will maximize forefoot eversion by pushing down on the first ray while pronating the midtarsal joint. He also maintains the rearfoot at a neutral position at the subtalar joint.

Q:

What are your footwear requirements for the standard orthosis you prescribe for plantar heel pain?

A:

For patients with heel pain, Dr. Williams will use “anything that will accommodate the orthotic and the patient’s foot.” Dr. Williams will explain to patients that certain shoes will tend to improve orthotic outcomes but wearing the orthotic device most of the time will tend to do that better than not wearing the devices because the orthosis will not fit into certain shoes.

“You really have to ask what types of shoes (patients) regularly wear at work and when active,” says Dr. Williams. “Making a device to fit the shoes most worn for patients works best when you can but this can also decrease outcomes if there are certain forefoot and digital prescription elements that can benefit the patients.”

Similarly, Dr. Fullem will see what types of shoes the patient may have to wear for work. He may accordingly change his prescription to be less bulky and sometimes eliminate an external rearfoot post, and have the shell be a thin composite or polyethylene type device. If Dr. Fullem feels the patient needs more support, he will send the patient to a local running specialty store and have him or her get a running shoe, even if the patient is not a runner. He notes that some of his 85-year-old patients wear Hoka One One shoes and “usually love them.”

First and foremost, Dr. Richie advises that the shoe must have a stable shank. “Placing any type of foot orthosis in a minimalist shoe or lightweight Skecher shoe is doomed to failure,” he says.

Dr. Richie notes a heel drop of 12 mm or more is “critical to success.” For casual shoes, he says there must be coverage of the vamp of the shoe proximal to the tarsometatarsal joints.

Dr. Fullem is a Fellow of the American Academy of Podiatric Sports Medicine. He is in private practice in Clearwater, Fla.

Dr. Williams is the Director of Gait Analysis Studies at the Weil Foot & Ankle Institute. He is a Past President and Fellow of the American Academy of Podiatric Sports Medicine. Dr. Williams is the Past President and Fellow of the American Academy of Podiatric Sports Medicine. He is the Director of Breakthrough Sports Performance, LLC in Chicago.

Dr. Richie is an Adjunct Associate Professor within the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Calif. He is a Fellow and Past President of the American Academy of Podiatric Sports Medicine. Dr. Richie is a Fellow of the American College of Foot and Ankle Surgeons. He is in private practice in Seal Beach, Calif.

Reference

1.     Kogler GF, Veer EB, Solomonidis SE, Paul JP. The influence of medial and lateral placement of orthotic wedges on loading of the plantar aponeurosis. In vitro study. J Bone Joint Surg. 1999; 81(10):1403-1413.

For further reading, see “Orthoses For Heel Pain: Essential Considerations For Optimal Results” in the August 2018 issue of Podiatry Today, “Current Insights On Neutral Casting And Biomechanical Exams For Orthotic Prescriptions” in the October 2017 issue, or “Key Pearls On Orthotic Casting And Fabrication” in the December 2016 issue.

For other related content, see Dr. Richie’s DPM Blog at https://tinyurl.com/ybxqr8w3 or Dr. Williams’ DPM Blog at https://tinyurl.com/y7db7qbw .