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A Novel Quick Release Mechanism for Ankle Foot Orthosis Struts
W Li1, N Baddour1, E D Lemaire2,3
1Department of Mechanical Engineering, University of Ottawa, Ottawa, Canada.
Canadian Prosthetics & Orthotics Journal
|August 24, 2023
Summary
This study introduces a novel quick release ankle-foot orthosis (QRAFO) that significantly reduces strut swapping time, enhancing mobility and quality of life for users by allowing activity-specific stiffness adjustments.
Area of Science:
- Biomechanics
- Orthotics and Prosthetics
- Materials Science
Background:
- Posterior dynamic element ankle-foot orthoses (PDEAFOs) utilize carbon fibre struts for energy storage and release.
- Current PDEAFOs have time-consuming strut attachment methods, hindering activity-specific stiffness adjustments.
Purpose of the Study:
- To design a novel quick release ankle-foot orthosis (QRAFO) enabling rapid, daily strut swapping.
- To improve ankle biomechanics for diverse user activities through adaptable orthosis stiffness.
Main Methods:
- Developed a QRAFO prototype featuring a quick-release mechanism with a key, pin, anchor, and immobilization pin.
- Utilized SolidWorks for prototype modeling and simulation.
- Conducted mechanical tests (Instron 4482) for strength evaluation under running and downhill walking loads.
- Performed functional tests with four participants to assess quick-release efficiency and strut swap times.
Main Results:
- Simulations and mechanical tests confirmed the QRAFO's structural integrity under tested loads.
- Participants achieved strut swaps in 25.01 ± 3.66 seconds, significantly faster than the 60.48 ± 10.88 seconds for bolted connections.
- With practice, strut swap times decreased to under 10 seconds.
Conclusions:
- The QRAFO's quick-release mechanism is robust for various activities and drastically reduces strut swap time.
- This innovation allows for easy and rapid adjustment of orthosis stiffness, improving user mobility and quality of life.
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