A continuous loading apparatus for measuring three-dimensional stiffness of ankle-foot orthoses.
This paper describes a novel device to evaluate the mechanical properties of ankle foot orthoses (AFOs). The apparatus permits the application to AFOs of continuous three-dimensional (3D) movements between specified and settable endpoints. Using an x-y robot with a rotary stage and a six-component load cell, characteristic displacement versus reaction force curves can be generated and consequently the ankle moments can be determined as a function of dorsi/plantar flexion, inv/eversion and int/external rotation. Representative curves for two polypropylene lateral leaf AFOs, different in shape but produced for the same leg by a skilled orthotist, are presented to illustrate the capabilities of the novel testing system. The metrological investigation showed that the apparatus creates a highly repeatable data set (uncertainty < or = 1% FSO).
Cappa
Paolo
P
Department of Mechanics and Aeronautics, University of Rome La Sapienza, Via Eudossiana 18, Rome, Italy.
Patanè
Fabrizio
F
Di Rosa
Giuseppe
G
D000842:Ankle / Q000503:physiopathology*; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000295:instrumentation* / Q000379:methods; D005528:Foot / Q000502:physiology*; D009989:Orthotic Devices; D011474:Prosthesis Design; D013314:Stress, Mechanical; D016474:Weight-Bearing