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Logo for the Journal of Rehab R&D
Volume 43 Number 7, November/December 2006
Pages 857 — 870


Abstract - Kinematic and kinetic comparisons of transfemoral amputee gait using C-Leg® and Mauch SNS® prosthetic knees

Ava D. Segal, MS;1-2* Michael S. Orendurff, MS;1,3 Glenn K. Klute, PhD;1-2,4 Martin L. McDowell, CPO;1
Janice A. Pecoraro, RN;1 Jane Shofer, MS;1 Joseph M. Czerniecki, MD1,3

1Department of Veterans Affairs (VA), Rehabilitation Research and Development Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, VA Puget Sound Health Care System, Seattle, WA; Departments of 2Mechanical Engineering, 3Rehabilitation Medicine, and 4Electrical Engineering, University of Washington, Seattle, WA
Abstract — The C-Leg® (Otto Bock, Duderstadt, Germany) is a microprocessor-controlled prosthetic knee that may enhance amputee gait. This intrasubject randomized study compared the gait biomechanics of transfemoral amputees wearing the C-Leg® with those wearing a common noncomputerized prosthesis, the Mauch SNS® (Ossur, Reykjavik, Iceland). After subjects had a 3-month acclimation period with each prosthetic knee, typical gait biomechanical data were collected in a gait laboratory. At a controlled walking speed (CWS), peak swing phase knee-flexion angle decreased for the C-Leg® group compared with the Mauch SNS® group (55.2° ± 6.5° vs 64.41° ± 5.8°, respectively; p = 0.005); the C-Leg® group was similar to control subjects' peak swing knee-flexion angle (56.0° ± 3.4°). Stance knee-flexion moment increased for the C-Leg® group compared with the Mauch SNS® group (0.142 ± 0.05 vs 0.067 ± 0.07 N˛m, respectively; p = 0.01), but remained significantly reduced compared with control subjects (0.477 ± 0.1 N˛m). Prosthetic limb step length at CWS was less for the C-Leg® group compared with the Mauch SNS® group (0.66 ± 0.04 vs 0.70 ± 0.06 m, respectively; p = 0.005), which resulted in increased symmetry between limbs for the C-Leg® group. Subjects also walked faster with the C-Leg® versus the Mauch SNS® (1.30 ± 0.1 vs 1.21 ± 0.1 m/s, respectively; p = 0.004). The C-Leg® prosthetic limb vertical ground reaction force decreased compared with the Mauch SNS® (96.3 ± 4.7 vs 100.3 ± 7.5 % body weight, respectively; p = 0.0092).
Key words: amputee, biomechanics, C-Leg®, gait, kinematics, kinetics, knee, microprocessor, rehabilitation, transfemoral.

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