Related Experiment Video
Updated: Jan 14, 2026
Engineering Platform and Experimental Protocol for Design and Evaluation of a Neurally-controlled Powered Transfemoral Prosthesis
Published on: July 22, 2014
Toward personalizing prosthesis prescription: A take-home study of three microprocessor-controlled prosthetic knees:
Kinsey Herrin1,2, Sujay Kestur1, Sixu Zhou1,2
1Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA.
Background:
Previous studies on microprocessor-controlled prosthetic knees (MPKs) often investigate benefits of MPKs as a class of knees rather than clinically relevant differences between specific knees, despite their distinct features.
Objectives:
To systematically evaluate and report outcomes associated with three commercially available MPKs following a standardized real-world use period.
Design:
Randomized crossover study.
Setting:
Research laboratory and community environment.
Participants:
Ten patients with transfemoral amputation.
Interventions:
Three MPKs were fitted, trained, and worn for a 1-week period including C-Leg 4.0 (Ottobock, Duderstadt, Germany), Rheo Knee-Model RM7 (Össur, Reykjavik, Iceland), and Power Knee-PKA01 (Össur, Reykjavik, Iceland).
Main Outcome Measures:
Primary outcomes were the 10-meter walk test (10-mwt), the 2-minute walk test (2-mwt), and the Prosthesis Evaluation Questionnaire (PEQ). Secondary outcomes were stance time asymmetry, physiological cost index, stair and ramp speeds, the narrowing beam walking test, and community ambulation monitoring.
Results:
Participants walked 11% faster in Rheo than Power Knee during the 10-mwt (95% confidence interval [CI]: 0.046-0.184, p = .015). In the 2-mwt, participants walked 12% faster in C-Leg (95% CI: 0.034-0.241, p = .003) and 9% faster in Rheo (95% CI: 0.031, 0.163, p = .027) than in Power Knee. On the PEQ, participants reported greater satisfaction with C-Leg compared to Power Knee (p = .006). Ramp ascent speed was 8% faster in Rheo than Power Knee (95% CI: 0.026-0.130, p = .024). No significant differences were found for other secondary outcomes. Notably, 10 of 12 outcomes showed individuals performing their best by a defined difference on an MPK different from the cohort's best-performing MPK.
Conclusions:
Participants walked faster in C-Leg and Rheo than Power Knee and reported greater satisfaction with C-Leg. Consideration of patient needs and characteristics may allow more individualized MPK prescription and thereby improve rehabilitation outcomes.
Database Registration:
NCT06399471.
