CHICAGO — Changing the height and durometer of an orthosis affected the loading of the foot and may have the potential to improve overall gait, according to a speaker at the American Academy of Orthotists and Prosthetists Annual Meeting and Scientific Symposium, here.
Andrea J. Ikeda, CP, of the Extremity Trauma and Amputation Center of Excellence, and colleagues, conducted a study to determine the influence of heel wedge properties on gait of patients using an Intrepid Dynamic Exoskeletal Orthosis (IDEO).
According to Ikeda, the IDEO is a dynamic response device that is designed to restore function. It includes a proximal cuff with a low posterior trimline; flexible posterior struts; and a rigid, supramalleolar, full-length footplate shaped for smooth rollover and use of a heel wedge.
The heel wedge is an “integral component of the IDEO system,” Ikeda said. “It is made of rubber-style urethane foam and its compression simulates plantar flexion during loading response.”
The study included 12 unilateral IDEO users (11 males and one female) with an average age of 32 years and average weight of 213 pounds. Injuries included fracture, tendon rupture, osteoarthritis, fusion and volumetric muscle loss.
The participants walked on level ground at a controlled speed, using the IDEO and standardized shoes. Each walked in six different heel wedges of three heights and two durometers, in a randomized order. Kinematic and kinetic gait data were collected and the measures were repeated. Outcome variables included center-of-pressure velocity, ankle moment and rollover shape. The researchers examined for overall comfort and smoothness of gait.
According to study results, for ankle moment, height and durometer interaction significantly affected time of zero crossing. Height and durometer interaction also affected rollover shape of the center-of-curvature position. Ikeda said shorter, softer heel wedges resulted in earlier and greater peak center-of-pressure velocity and the center-of-pressure velocity position predictably influenced ankle moment zero crossing time. The extended wedges, Ikeda added, extended further distally under the footplate, decreased peak center-of-pressure velocity and offered more controlled rollover.
“Adjusting the heel wedge is a simple, straightforward way to adjust the IDEO heel wedge shoe system and has great potential to improve an individual’s gait,” Ikeda said. “[The] use of a heel wedge with other types of [ankle-foot orthoses] AFOs may also help improve smoothness and ease of rollover.” – by Shawn M. Carter
Ikeda AJ. Effects of heel wedge properties on gait with the Intrepid Dynamic Exoskeletal Orthosis (IDEO). Presented at: American Academy of Orthotists and Prosthetists Annual Meeting and Scientific Symposium; March 1-4, 2017; Chicago.
Disclosure: Ikeda reports she is a member of the Extremity Trauma and Amputation Center of Excellence.