How To Prescribe Orthotics For Runners

Volume 15 - Issue 8 - August 2002
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Case Studies: Treating Conditions Of Competitive Runners

For all of the following clinical scenarios, assume the runner is 175 lbs., is 5 foot, 10 inches tall, and is a competitive athlete.

Case One: Peroneal Tendonitis
The patient presents with a six-month history of outside ankle pain bilaterally. He has been increasing the number of miles he runs to train for a marathon. The pertinent physical exam finding is a pes cavus foot type with calcaneal resting position of 3 degrees inverted. You’re able to elicit pain with palpation of the peroneal tendon along the lateral malleolus and distally at the insertion base of the styloid process.

Recommended prescription: 5/32 polypropylene shell, heel cup of 16 mm, wide width plate, maximum arch fill, 2-mm lateral skive and a 4/4 EVA rearfoot post with no lateral bevel bilaterally.

Case Two: Posterior Tibial Tendosynovitis
The patient presents with a six-month history of inside ankle pain that is greater in the left foot than the right. He indicates shooting as well as tearing sensation around the arch, again with greater sensation in the left foot.

The pertinent physical exam finding is an adult-acquired flatfoot that is more pronounced on the left foot than the right. The patient has a calcaneal resting position of 6 degrees everted on the left foot and 2 degrees everted on the right foot. You’re able to elicit pain with light palpation of the posterior tibial tendon bilaterally. You also notice that the pain you elicit with single toe raises is greater on the left foot than the right foot.

Recommended prescription: 1/8 polypropylene shell, heel cup height of 18 mm, extra wide arch plate, minimal arch fill, 2-mm skive bilaterally and 2 degree inversion on the left foot only. Here the recommendation is for a more flexible device, but the minimal arch fill and combination skive and inversion will provide tighter control of the foot bilaterally.

Case Three: Sesamoiditis
The patient presents to the office with a six-month history of great toe pain on the left foot. The pertinent physical exam finding is a pes planovalgus foot type with a calcaneal resting position of 2 degrees everted bilaterally. You’re able to elicit pain upon palpation of the fibular sesamoid first metatarsal phalangeal joint on the left foot.

Recommended prescription: 5/32 polypropylene shell, heel cup height of 16 mm, wide arch plate, standard arch fill and a 2-mm skive bilaterally. You would employ a 1/8 EVA soft topcover as well as a reverse Morton’s extension on the left foot only.

Case Four: Second Metatarsal Stress Syndrome
The patient presents to the office with a six-month history of second toe pain on his left foot. He describes a “shooting” pain and that it feels like “walking on a stone.” The pertinent physical exam finding is a pes planovalgus foot type with a calcaneal resting position of 4 degrees everted bilaterally. There is a hypermobile first metatarsal head on the left that is greater than the right.

Recommended prescription: 1/8 polypropylene shell, heel cup height of 18 mm, extra wide arch plate, minimal arch fill, a 2-mm skive bilaterally and 2-degree inversion bilaterally. You should use a 1/16 EVA soft topcover as well as a slot accommodation to offweight bear the second metatarsal head.

Here is a polypropylene functional foot orthosis with an EVA rearfoot post. The author notes that one of the great advantages of polypropylene is its ability to conform to curves of the foot very tightly.

This combination functional foot orthosis is comprised of a 1/8 polypropylene shell with EVA arch fill and a bottom cover. This type of orthosis allows for increased shock absorption.

Here is a polypropylene functional orthosis with an intrinsic accommodation for a navicular prominence

Here you can see a reverse Morton’s extension made out of korex to off-weightbear the first ray.

Here is a slot accommodation that was made in order to off-weightbear a prominent metatarsal head.

Author(s):

By Alona Kashanian, DPM

Most competitive runners do not like being restricted in their regimens. As we all know, these patients are very anxious to resume their running activity. However, they do look to foot and ankle specialists for help in reducing the inflammation, preventing and/or recuperating from lower extremity injuries. In order to write effective orthotic prescriptions for these patients, be sure to pay attention to cast correction, materials and additional bells and whistles.
The ability of the orthosis to control abnormal or excessive motion of the foot is more dependent on the size of the device and the cast correction techniques. Cast correction can be broken down into heel cup depth, orthotic width, positive cast arch fill, medial skive, lateral skive, inversion and plantar fascial groove, all of which are important components to orthotic prescription writing for the athletic runner.
The heel cup depth should be at least 14 mm in depth. The orthotic device width is recommended to be at least extra wide in depth. A deeper heel cup and a wider device provide more surface area for the orthotic to control the foot. The deeper you make the heel cup and the wider you make the device, it allows you to utilize the skive technique as well as the inverted technique to give a maximum benefit to the runner. If the athlete is wearing a sprinter’s shoe, which is cut narrower and shallower to the runner’s foot, you would have to modify the prescription.
The amount of arch fill in the positive cast work allows for better contour to the athlete’s foot and control of the biomechanical pathologies. While a minimal arch fill will allow the orthotics to closely hug the medial plantar arch of the foot and enable you to provide maximum control of the hyperpronated foot type, be aware that it will also push the foot higher onto the vamp of the shoe and increase the rigidity of the orthotic material.

It is recommended that you use a standard to maximum arch fill, depending on the pathology and runner’s foot type. The runner with an everted rearfoot and a pes planovalgus foot type in stance will benefit from an orthotic with standard arch fill, whereas an athlete with an inverted rearfoot and a pes cavus foot type will benefit from an orthotic with maximum arch fill.

What You Should Know About Intrinsic Cast Correction Techniques
Using the medial skive technique allows you to incorporate a varus wedge affect into the medial aspect of the orthotic’s heel cup. The increments of control with the medial skive range from 2 mm to 6 mm. An increase in the increments of the skive causes the heel cup tend to narrow. Therefore, when you’re treating an adult athlete, using a 6 mm skive is rarely recommended. The medial skive technique is recommended for the runner with a hyperpronated foot type.
If the runner presents with a calcaneal stance position of 2 to 4 degrees of eversion, I recommend using a 2 mm skive. If the runner presents with a calcaneal stance position of 4 to 6 degrees of eversion, use a 4 mm skive. If the calcaneal stance position is higher than 6 degrees everted, you should use an inverted and skive technique in combination.
Conversely, when you employ the lateral skive intrinsic cast correction technique, you’re able to incorporate a valgus wedge effect into the lateral aspect of the orthotic’s heel cup. The same increments are used for the lateral as the medial skive technique. The indications for using the lateral skive are for athletes with lateral ankle instability and peroneal tendonitis, as well as any pathology which increases lateral column loading.
Inversion is another intrinsic correction technique which incorporates a varus wedge along the medial column of the foot. The number of degrees recommended with the inversion technique varies. Reviewing the literature, it was initially recommended to invert the cast from 10 to 45 degrees, depending on the runner’s severity of calcaneal eversion.