Personalizing MPK Prescription

Not Applicable

Completed

Brief Summary: In current clinical prosthetic practice, there is no evidence based method for selecting a microprocessor knee (MPK) joint for a patient with an above the knee amputation. Of individuals with amputation in veteran and service member populations, approximately 35% present with an above the knee amputation. It is well understood in clinical practice that MPKs provide numerous benefits to patients with amputations above the knee including improved gait, safety, comfort, confidence, reduced falls, balance, patient satisfaction and reduced energy expenditure, greater ease in negotiating varying terrains, improvements in multi-tasking and cost effectiveness. Studies that have investigated commercially available MPKs tend to lump all of them together within a single group rather than teasing out individual differences between each knee. Therefore, clinicians are left to rely on their own intuition and past experiences with an MPK when selecting for a patient with an above the knee amputation rather than making their decision based on evidence collected from the specific patient. This may mean that some individuals with an above the knee amputation may not be receiving the best component for them which may delay or inhibit their rehabilitation potential following their amputation.

Recruitment & Eligibility

Inclusion Criteria

A unilateral transfemoral amputation of the lower limb at least six months post fitting of definitive lower extremity prosthesis
Habitual use of a lower extremity prosthesis in daily living activities (based on assessment of a physiatrist and/or prosthetist and patient self-report)
Aged between 18 to 75 years
K3 or K4 level ambulators who can perform all locomotor tasks of interest (based on assessment of a physiatrist and/or prosthetist)

Exclusion Criteria

Individuals with any significant neuromuscular or musculoskeletal disorder or other comorbidity that would interfere with participation (based on assessment of the physiatrist and/or prosthetist and patient self-report)
Individuals who have open wounds on their residual limb
Individuals with known visual impairments that would prevent them from safely operating a prosthesis during over ground walking or ascending stairs (based on assessment of the physiatrist and/or prosthetist and patient self-report)
Individuals with known hearing impairments or who use hearing aids that would prevent them from responding to an auditory instruction (based on assessment of the physiatrist and/or prosthetist and patient self-report)
Individuals who are currently pregnant (based on patient self-report) due to slight risk of falling during experiments

Arm && Interventions

Group	Intervention	Description
Take home study	Microprocessor prosthetic knee	-

Primary Outcome Measures

Name	Time	Method
Ten Meter Walking Test	1 month	Self selected walking speed over ten meters of walking over ground.
Two Minute Walking Test	1 month	Self selected walking speed over two minutes of walking over ground.
Prosthetic Evaluation Questionnaire (PEQ)	1 month	A patient reported survey on perceptions of a prosthesis. Scores range zero to one hundred with zero being representing a negative patient reported outcome and one hundred representing a positive patient reported outcome.

Secondary Outcome Measures

Name	Time	Method
Stance Time Asymmetry Index	1 month	Stance time asymmetry index measures the percent difference in stance time between the prosthetic and sound side limbs. A value equal to zero is indicative of perfect symmetry. Negative values of ST asymmetry index are indicative of increased time spent on the sound side and positive values are indicative of increased time on the prosthetic side.
Narrowing Beam Walking Test	1 month	A measure of balance via walking down a narrowing beam.
Reported Falls	1 month	Average reported falls per day.
Physiological Cost Index	1 month	A clinical measure of energy expenditure. This formula consists of working heart minus resting heart rate divided by speed.
Stair Ascent Speed	1 month	Self selected walking speed during stair ascent.
Stair Descent Speed	1 month	Self selected walking speed while descending stairs.
Ramp Ascent Speed	1 month	Self selected walking speed while ascending a 5 degree incline.
Ramp Descent Speed	1 month	Self selected walking speed while descending a 5 degree incline.
Steps Per Day	1 month	Steps per day as measured by StepWatch.