A Continuous Loading Apparatus for Measuring Three-dimensional Stiffness of Ankle-Foot Orthoses

[+] Author and Article Information
Paolo Cappa, Fabrizio Patanè

Department of Mechanics and Aeronautics,  University of Rome “La Sapienza,” Via Eudossiana 18, Rome, Italy and Paediatric Neuro-rehabilitation Division,  Children’s Hospital “Bambino Gesù,” Via Torre di Palidoro, Passoscuro Rome, Italy

Giuseppe Di Rosa

Paediatric Neuro-rehabilitation Division,  Children’s Hospital “Bambino Gesù,” Via Torre di Palidoro, Passoscuro, Rome, Italy

J Biomech Eng 127(6), 1025-1029 (Jul 11, 2005) (5 pages) doi:10.1115/1.2049313 History: Received March 09, 2005; Revised July 11, 2005

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 1% FSO).

Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 3

Variation of total moment Mt, expressed in N m as a function of α and β, expressed in degrees. The diagrams are relative to: (a) γ=−15°,(β)γ=0°, (c) γ=15°, for the EAFO; (d) γ=−15°, (e) γ=0°, (f) γ=15°, for the IAFO. The directions and the values θ of maximum and minimum stiffness are also indicated.

Grahic Jump Location
Figure 2

Loading apparatus equipped with the IAFO. The EAFO is also depicted.

Grahic Jump Location
Figure 1

Kinematic scheme of the testing apparatus: (a) foot displacements decomposed in the three cardan’s rotations α, β, and γ; (b) reference frames 0, 3, 4, and S (fixed frame) in a generic foot position




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In