Biomechanical Evaluation of the Ossur Power Knee Compared to Ossur Rheo XC in Transfemoral Amputees

What this Trial Is About

The trial investigates the biomechanical effects of the Ossur Power Knee, a microprocessor-controlled prosthetic knee with active motor-driven flexion and extension, compared to the Ossur Rheo XC, a passive microprocessor-controlled knee. The study focuses on unilateral transfemoral amputees aged 45 to 75 years, aiming to evaluate differences in walking and mobility, including a comparison by gender to identify any sex-specific prosthesis needs. The research is designed to improve understanding of prosthetic knee function and enhance prosthesis selection for users. Participants will be fitted with both the Ossur Power Knee and the Ossur Rheo XC in a crossover design, receiving one month of accommodation with each device before evaluation. The Power Knee provides powered knee flexion and extension, while the Rheo XC modulates damping passively during movement. Subjects will perform walking, stair climbing, slope navigation, and sit-to-stand activities while wearing each knee. Questionnaires and at-home diaries will capture user perceptions of comfort, exertion, and stability. During the study, detailed biomechanical data such as walking speed, metabolic energy cost, symmetry during sit-to-stand movements, step length, toe clearance, leg loading, and pelvic motion will be collected. Assessments occur after each one-month accommodation period. The study uses motion analysis labs for gait data and includes participant self-reporting. The total participation timeline includes fitting, training, accommodation, and evaluation phases for both knee types, allowing each participant to serve as their own control.

A Biomechanical Evaluation of the Ossur Power Knee in Persons With Transfemoral Amputation