Current Concepts In Orthotic Prescriptions

Prefabricated orthoses can play a valuable role in the podiatric practice. Accordingly, our expert panelists offer insights on the key characteristics of these devices and how they utilize prefabs in the treatment of patients. The panelists also discuss the use of orthotics to prevent and treat common soccer-related injuries.

Q:

How valuable are prefabricated orthoses in your clinical practice?

A:

All four panelists emphasize the value of using prefab orthoses. Due to the demands and space issues of her private practice, Cherri Choate, DPM, has one prefab option for dress shoes and two to three prefab options for active shoes. When it comes to active prefabs, she uses a device with a deep heel cup, a wide semi-rigid plate, a medial heel skive and an optional topcover. As she tends to encourage in-office modification of prefabricated devices, Dr. Choate prefers having plate and topcover materials that are easy to work with and easy to fit in the majority of active shoes.

   For dress orthoses, Dr. Choate prefers the most streamlined device possible. She prefers to use graphite or graphite composite materials with a very shallow heel cup and a neutral, low bulk topcover.

    “For many years, I tried to use polypropylene devices for dress shoes and I was only minimally successful. Once I changed to graphite, the patient’s shoe options increased exponentially and the time of use also increased,” notes Dr. Choate.

   Jenny Sanders, DPM, dispenses prefabricated orthotics for dress shoes after fitting her patients with a non-dress shoe custom device. Due to the variability of dress shoe heel heights and volume, she notes that a low profile, thin device can be much more versatile than a single custom device.

    “The tradeoff is functional control but how functional can a custom orthotic be in a 2-inch high heel anyway?” she says.

   Dr. Sanders will also prescribe a prefabricated orthotic when the patient presents with mild symptoms such as plantar fasciitis or metatarsalgia in the absence of other significant biomechanical issues.1

   Many patients of Daisy Sundstrom, DPM, bring in over-the-counter inserts they have tried to use in supportive shoegear for various problems without success. She prescribes prefabs for patients with a relatively normal foot type (no excessive planus, cavus or other deformities), especially those with some degree of ligamentous laxity and for patients who would benefit from mild to moderate correction.

   Alona Kashanian, DPM, recommends prefabricated devices to 30 percent of her patients who need biomechanical control and correction of their foot deformity.

Q:

What characteristics of a prefab do you find valuable?

A:

Drs. Sundstrom, Kashanian and Sanders cite rigidity as valuable with Dr. Sundstrom emphasizing the importance of the prefab’s material and thickness.

    “I have yet to find an OTC arch support that is rigid enough to support the average weight of an individual patient without collapsing,” she says. “I usually tell patients, ‘If you can bend it with your hands, chances are, it won’t support your body weight.’”

   As Dr. Sundstrom notes, the disadvantage of the prefab is that quite often the device is not wide enough and the medial longitudinal arch is not high enough.

   Dr. Sanders values semi-rigidity, ease of fit into shoes and the ability to further customize if necessary. For example, she considers whether she can grind in a plantar fascial groove or add a topcover. For her prefabs, Dr. Kashanian uses a rigid plastic or graphite shell.

Q:

With the recent increase in the popularity of soccer, what type of orthotic device do you prescribe for soccer injuries or prevention, considering the extremely low volume of soccer shoes?

A:

Dr. Sanders tailors the orthotic to the specific pathology. For example, she uses a medial heel skive for a medially deviated subtalar joint axis and minimum fill and/or inversion for excessively pronated rearfoot.2-5 She advocates using a shallow heel cup of 8 to 10 mm.

   Likewise, Dr. Sundstrom prescribes orthoses based on the patient’s pathology. For those with frequent inversion ankle sprains, she will incorporate a valgus forefoot extension. If the problem is jamming in the first metatarsophalangeal joint or functional hallux limitus, she adds a reverse Morton’s extension. For Dr. Sundstrom, flatfoot “is probably the most challenging problem when dealing with a low profile soccer cleat” because the necessary components use so much room in the shoe.

   Carbon graphite is Dr. Sanders’ preferred orthotic material for soccer cleats due to the low volume. Similarly, Dr. Kashanian most frequently recommends that soccer players use a graphite functional device. Given the low profile of the carbon graphite material, Dr. Kashanian says the orthosis does not need a lot of room in the soccer shoe. She says one can add a skive to the functional graphite orthoses or inverted skives for biomechanical control. Dr. Kashanian says the one disadvantage of graphite orthoses is the inability to incorporate a sweet spot or plantar fascial groove in the shell. Due to the low volume of the soccer cleat, she does not recommend a bulky rearfoot post.

   Regardless of pathology, Dr. Sundstrom uses a low-profile device. She prefers a semi-rigid polypropylene shell with no rearfoot post, a shallow heel cup and a narrow or medium width. The device should also have minimal cast fill and a medial skive, usually with some degree of inversion, according to Dr. Sundstrom.

   Dr. Sundstrom uses a thin EVA or Spenco-type topcover on the sulcus while Dr. Sanders uses a vinyl topcover. She says this holds up best against sweat and friction. Furthermore, Dr. Sundstrom recommends that patients wear a more supportive type of device, which provides better control, in their street shoes the remainder of the time.

   Noting that she does not prescribe a high volume of soccer orthotics, Dr. Choate’s first goal is making sure the device fits in the shoe.

    “I can order a great orthotic but if it is too bulky to fit in the shoe or causes neuralgia during use, then it is not the best choice for the situation,” notes Dr. Choate.

   To that end, Dr. Choate uses a low-volume, streamlined device such as a graphite shell with a thin, somewhat stiff topcover to the toes. In addition, to add stability and protection for the ankle and foot on uneven terrain, she recommends using a 1/16-inch reverse Morton’s extension and minimal lateral bevel on the rearfoot post.

   Citing the number of inversion injuries in soccer, Dr. Choate suggests the use of an ankle brace if the patient has any history of ankle sprains. She cautions that the brace and orthotic may be competing for space. In many active patients, she uses the Active Ankle Brace (Active Ankle). Dr. Choate notes the device’s plate fits under the rearfoot area of the orthotic and provides “excellent control” of frontal plane motion.

   Dr. Choate is an Assistant Professor in the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University.

   Dr. Kashanian is in private practice in Los Angeles. She is a Medical Consultant for ProLab Orthotics/USA in Napa, Calif.

   Dr. Sanders is in private practice in San Francisco. She writes a monthly blog for Podiatry Today. For more information, please visit www.podiatrytoday.com/blogs. Dr. Sanders also blogs at www.drshoe.wordpress.com .

   Dr. Sundstrom is affiliated with the Orthopedics, Podiatry and Sports Medicine Department in the Division of Musculoskeletal Services at the San Francisco Kaiser Permanente Medical Center. She is board certified in foot surgery and in reconstructive rearfoot and ankle surgery.

   Dr. Scherer is a Clinical Professor at the Western University of Health Sciences College of Podiatric Medicine at Pomona, Calif. He is also the CEO of ProLab Orthotics/USA.

References

1. Landorf KB, Keenan AM, Herbert RD. Effectiveness of different types of foot orthoses for the treatment of plantar fasciitis. J Am Podiatr Med Assoc. 2004; 94(6):542-9.
­2. Scherer PR, Sanders J, Eldredge DE, et al. Effect of functional foot orthoses on first metatarsophalangeal joint dorsiflexion in stance and gait. J Am Podiatr Med Assoc. 2006; 96(6):474-81.
3. Kirby KA. The medial heel skive technique: improving pronation control in foot orthoses. J Am Podiatr Med Assoc. 1992; 82(4):177-88.
4. Blake RL, Ferguson H. Foot orthosis for the severe flatfoot in sports. J Am Podiatr Med Assoc. 1991; 81(10):549-55.
5. Murley GS, Bird AR. The effect of three levels of foot orthotic wedging on the surface electromyographic activity of selected lower limb muscles during gait. Clin Biomech. 2006; 21(10):1074-80.

   For further reading, see “Emerging Insights On Orthotic Prescriptions And Modifications” in the February 2011 issue of Podiatry Today.