AFO map can aid in off-the-shelf ankle orthoses fittings

LAS VEGAS — A newly created AFO map can allow practitioners to determine the stiffness profile of off-the-shelf AFOs, aiding in orthotic ankle management for patients, according to a presenter at the Thranhardt Lecture series at the American Orthotic & Prosthetic Association National Assembly, here.

David Knapp

The AFO map was created by David Knapp, CPO, BSME, MEd, assistant professor of prosthetics and orthotics at the University of Hartford. Its creation was based on a study of 18 carbon fiber fitted AFOs from seven different manufacturers. The AFOs were tested using a surrogate limb rather than on patients to provide consistency among the tests and avoid patient fatigue. A typical orthopedic shoe was donned over the brace for each test.

“To verify consistency, we tested each AFO three times,” Knapp said.

The stiffness profile measured stiffness, neutral angle, range of motion and energy return. Factors that affected AFO function included the type of shoe worn; movement within the shoe; the fit and alignment of the limb; weight bearing; tissue displacement; muscle contractions; inconsistent step parameters; and the use of assistive devices.

“High energy return generally results in a more efficient gait. However, in cases where excessive [alignment irregularities] are present, energy return can lead to an inappropriate rate of counterproductive forces,” Knapp said. — by Amanda Alexander

For more information:

Knapp D. A Comparative Study of AFO Dynamics During Simulated Gait. Presented at: American Orthotic & Prosthetic National Assembly; Sept. 4-7, 2014. Las Vegas.

Disclosure: All AFO devices were provided to the study for free from the manufacturers.

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