Written by: Larry Huppin, DPM
11/30/2009 4:21 PM

A client question today:  

QUESTION
“I have a pt who is a marathon runner and is having B/L heel pain. He can control it somewhat by taping his foot (he was an athletic trainer) but as long as he keeps running, his heels bother him. He's 40 yrs old and weighs 160 pounds. He doesn't really hyper-pronate when he walks and his STJ is pretty stable. What type of material and top cover should I order with his orthotics? Would you recommend a certain heel cup depth for a runner? How much of a medial heel skive would you recommend? Any other tips for a running orthotic?? “

ANSWER
We recommend basing your orthoses more on the patient’s pathology rather than their activity. The activity comes into play when you are looking at how the device will fit into a shoe, but the pathology should drive your prescription.

The plantar fascia tightens when the first ray dorsiflexes (lengthening the foot and tightening the fascia). This will occur when the rearfoot everts or when the forefoot is everted (both situations increase force under the medial forefoot and can dorsiflex the first ray). .

If his rearfoot is stable and not everted than the most likely cause of heel pain is dorsiflexion of the first ray due to a flexible forefoot valgus or plantarflexed first ray (both of these conditions increase force under the forefoot. Thus, the orthosis should primarily act to prevent first ray dorsiflexion. To do this you want to be sure to plantarflex the first ray when taking the negative cast - try to get out any soft tissue varus. The orthosis made from that cast should do a good job of letting the first ray plantarflex and preventing dorsiflexing.

The topcover choice is up to you. I like 3mm soft EVA. It holds up well and is easy to work with. Also there is evidence in the literature that extra cushioning can decrease force through the lower extremity. Given that we recommend a layer of 1.5mm Poron be added to the bottom of the topcover for extra cushion.

In addition, you may want to use a reverse Morton's extension to encourage the first ray to plantarflex.

So, a good orthosis for this patient would be:

• 4mm vacuum formed polypropylene
• Standard heel cup depth
• Wide width (prevents irritation from medial edge of orthoses)
• Minimum cast fill
• No medial skive
• 2 degrees inversion (this raises the base of the first met to enhance plantarflexion)
• EVA topcover to toes
• 1.5mm Poron glued to bottom of topcover
• EVA 0/0rearfoot post
• Reverse Morton's Extension

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