Do Transfemoral Prostheses With Powered Prosthetic Knee Flexion and Extension Improve Mobility? A Biomechanical Evaluation of the Ossur Power Knee
VA Office of Research and Development
Summary
Microprocessor-controlled knees (MPKs) do not typically utilize motors to power joint rotation, but they automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the prosthesis user during gait. The Ossur Power Knee is the only commercially-available MPK that uses a motor to provide active power generation during walking and other activities. The purpose of this proposed investigation is to perform and compare biomechanical evaluations of the Power Knee and Ossur Rheo XC, a passive MPK, during walking and other activities by prosthesis users. Furthermore, mobility between male and female subjects will be compared to determine if there are differences in prosthetic knee usage on the basis of sex.
Description
The anatomical knee is a complex, polycentric joint characterized by a large range of motion in the sagittal plane and limited mobility in the coronal and transverse planes. The sagittal plane motion is used for progression in stance phase, and limb clearance and advancement in swing. Limb prostheses are intended to restore function and cosmesis in persons with limb loss. The complexity and function of prosthetic components have advanced significantly as technology has improved, but a state-of-the-art artificial limb is still a relatively poor substitute for an anatomical one. Microprocessor-c…
Eligibility
- Age range
- 45–75 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: * Unilateral, transfemoral amputation (any etiology). * Age from 45-75 years. * Residual limb length classified as standard (i.e., medium) to long. * Prosthesis user for at least 1 year prior to enrolling in the study. * K3 or K4 level ambulator. * Good sensation on their residual limb(s) (upon routine clinical examination). * Good skin integrity upon visual inspection. * Does not require the use of assistive devices to walk for short distances. * Not currently taking medications that are known to affect balance or gait. * Presents with good socket fit based upon a standar…
Interventions
- OtherPowered prosthetic knee joint
Subjects will be fitted and trained on the Ossur Power Knee. An accommodation of 1 month will be provided prior to evaluation with the knee joint.
- OtherConventional prosthetic knee joint
Subjects will be fitted and trained on the Ossur Rheo XC Knee. An accommodation of 1 month will be provided prior to evaluation with the knee joint.
Location
- Jesse Brown VA Medical Center, Chicago, ILChicago, Illinois