Journal of Rehabilitation Research & Development (JRRD)

Quick Links

  • Health Programs
  • Protect your health
  • Learn more: A-Z Health
Veterans Crisis Line Badge

Volume 51 Number 5, 2014
   Pages 803 — 814

Abstract — Passive prosthetic ankle-foot mechanism for automatic adaptation to sloped surfaces

Eric Nickel, MS;1 Jonathon Sensinger, PhD;2 Andrew Hansen, PhD1,3*

1Minneapolis Department of Veterans Affairs Health Care System, Minneapolis, MN; 2Prosthetic Design and Control Laboratory, Rehabilitation Institute of Chicago, Chicago, IL, and Departments of Physical Medicine and Rehabilitation and Mechanical Engineering, Northwestern University, Evanston, IL; 3Program in Rehabilitation Science, University of Minnesota, Minneapolis, MN

Abstract — This article describes the development of a prototype prosthetic ankle-foot system that passively adapts to surface slopes on each step of walking. Engineering analyses were performed to design the cam clutch and clutch engagement and disengagement mechanism. The prototype was tested by a veteran with a unilateral transtibial amputation. Kinematic and kinetic data were recorded while the subject walked on a treadmill at slopes ranging from −10 to +10 degrees. After each slope condition, the subject rated his level of exertion and socket comfort. The subject reported increased comfort and reduced exertion for downhill slopes when using the prototype compared with his usual prosthesis. The subject also expressed that when walking downhill on the prototype, it was the most comfortable he had ever been in a prosthesis. The prosthetic ankle torque-angle relationship shifted toward dorsiflexion for uphill and toward plantar flexion for downhill slopes when using the prototype, indicating slope adaptation, but this effect did not occur when the subject walked with his usual prosthesis. The prototype also demonstrated late-stance plantar flexion, suggesting the potential for storing and returning more energy than standard lower-limb prostheses.

Key words: adaptation, ankle, equilibrium point, foot, gait, passive prosthetic, prosthesis, ramps, slope, walking.

*Address all correspondence to Andrew H. Hansen, PhD; Minneapolis VA Health Care System, One Veterans Drive (Research-151), Minneapolis, MN 55417; 612-467-2910; fax: 612-725-2093. Email:

View HTML ¦ View PDF ¦ Contents Vol. 51, No.5

This article and any supplementary material should be cited as follows:
Nickel E, Sensinger J, Hansen A. Passive prosthetic ankle-foot mechanism for automatic adaptation to sloped surfaces. J Rehabil Res Dev. 2014;51(5):803–14.
ResearcherID/ORCID: Jonathon Sensinger, PhD: C-5012-2014

Go to TOP

Last Reviewed or Updated  Wednesday, September 3, 2014 9:19 AM

Valid HTML 4.01 Transitional