A Biomechanical Evaluation of the Ossur Power Knee in Persons With Transfemoral Amputation
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age45-75
SponsorVA Office of Research and Development
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Unilateral, transfemoral amputation (any etiology)
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
Disqualifiers
Bilateral amputations
Individuals with a knee disarticulation
Trial design
Design model
Crossover
Treatments tested in this trial
Powered prosthetic knee joint
Other interventionSubjects 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.
Conventional microprocessor-controlled prosthetic knee joint
Other interventionSubjects 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.
Treatment groups
20 Participants
are divided into 2 treatment groupsGroup A: Ossur Power KneeExperimental treatment 1 intervention
Group B: Ossur Rheo XC KneeActive comparator 1 intervention
Trial outcomes
Primary outcomes
1
Walking speed
Walking speed will be measured as participants walk on level ground at slow, normal and fast speeds.
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee component2
Metabolic energy cost
The metabolic energy rate will be measured as subjects walk at their freely selected speed on a level treadmill, which will be converted to metabolic energy cost (energy expended per unit distance).
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee component3
Sit-to-stand/stand-to-sit symmetry
Knee kinematics and load distribution between the sound and prosthetic sides will be measured as participants stand up and sit down in a chair.
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee componentSecondary outcomes
1
Step length
The step lengths of the sound and prosthetic sides will be measured as participants walk on level ground at slow, normal and fast speeds.
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee component2
Toe clearance during swing phase
Toe clearance during swing phase on the prosthetic side will be measured as participants walk on level ground at slow, normal and fast speeds.
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee component3
Sound leg loading rate
The sound leg loading rate during walking will be measured as participants walk on level ground at slow, normal and fast speeds.
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee component4
Kinematics of pelvic motion
Pelvic tilt, rotation and obliquity will be measured as participants walk on level ground at slow, normal and fast speeds.
Time frame
To be measured after the 1-month accommodation period of wearing each prosthetic knee componentSponsors and contacts
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Source ClinicalTrials.gov