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Logo for the Journal of Rehab R&D
Volume 43 Number 2, March/April 2006
Pages 239 — 246

Abstract - Gait efficiency using the C-Leg

Michael S. Orendurff, MS;* Ava D. Segal, BAS; Glenn K. Klute, PhD; Martin L. McDowell, CPO;
Janice A. Pecoraro, RN; Joseph M. Czerniecki, MD

Motion Analysis Laboratory, Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Rehabilitation Research and Development, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA
Abstract — Microprocessor-controlled prosthetic knees are claimed to improve gait efficiency in transfemoral (TF) amputees. This hypothesis was tested in a prospective randomized crossover trial that compared the Mauch SNS knee and the C-Leg microprocessor-controlled knee in eight TF amputees. The subjects were given a 3-month acclimation period in each knee. Then, their net oxygen cost (mL/kg/m) was measured while they walked overground at four speeds in random order: 0.8 m/s, 1.0 m/s, 1.3 m/s, and self-selected walking speed (SSWS). The C-Leg caused small reductions in net oxygen cost that were not statistically significant compared with the Mauch SNS at any of the walking speeds (p > 0.190). Subjects chose higher SSWSs with the C-Leg compared with the Mauch SNS (mean standard deviation = 1.31 0.12 m/s vs 1.21 0.10 m/s, respectively, p = 0.046) but did not incur higher oxygen costs (p = 0.270), which suggests greater efficiency only at their SSWS.
Key words: amputee, biomechanics, C-Leg knee, efficiency, gait, microprocessor control, oxygen cost, prosthetic knee, transfemoral, walking.

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