Effects of altering heel wedge properties on gait with the Intrepid Dynamic Exoskeletal Orthosis. (June 2018)

• Record Type: Journal Article
• Authors: Ikeda, Andrea J; Fergason, John R; Wilken, Jason M
• Is Part Of: Prosthetics and orthotics international. Volume 42:Number 3(2018)
• Page Start: 265
• Page End: 274
• Publication Date: 2018-06
• Subjects: Biomechanics of prosthetic/orthotic devices -- biomechanics -- lower limb orthotics -- orthotics -- rehabilitation of orthoses users -- rehabilitation -- IDEO; Orthopedic apparatus -- Periodicals; Prosthesis -- Periodicals; Implants, Artificial -- Periodicals; 617.905
• DOI: 10.1177/0309364617728116
• Languages: English
• ISSNs: 0309-3646

Abstract

Background: The Intrepid Dynamic Exoskeletal Orthosis is a custom-made dynamic response carbon fiber device. A heel wedge, which sits in the shoe, is an integral part of the orthosis-heel wedge-shoe system. Because the device restricts ankle movement, the system must compensate to simulate plantarflexion and allow smooth forward progression during gait. Objectives: To determine the influence of wedge height and durometer on the walking gait of individuals using the Intrepid Dynamic Exoskeletal Orthosis. Study design: Repeated measures. Methods: Twelve individuals walked over level ground with their Intrepid Dynamic Exoskeletal Orthosis and six different heel wedges of soft or firm durometer and 1, 2, or 3 cm height. Center of pressure velocity, joint moments, and roll-over shape were calculated for each wedge. Results: Height and durometer significantly affected time to peak center of pressure velocity, time to peak internal dorsiflexion and knee extension moments, time to ankle moment zero crossing, and roll-over shape center of curvature anterior-posterior position. Wedge height had a significant influence on peak center of pressure velocity, peak dorsiflexion moment, time to peak knee extension moment, and roll-over shape radius and vertical center of curvature. Conclusion: Changes in wedge height and durometer systematically affected foot loading. Participants preferred wedges which produced ankle moment zero crossing timing, peak internal knee extension moment timing, and roll-over shape center of curvature anterior-posterior position close to that of able-bodied individuals. Clinical relevance: Adjusting the heel wedge is a simple, straightforward way to adjust the orthosis-heel wedge-shoe system. Changing wedge height and durometer significantly alters loading of the foot and has great potential to improve an individual's gait.