Impact of stance phase microprocessor-controlled knee prosthesis on ramp negotiation and community walking function in K2 level transfemoral amputees.
BACKGROUND
Microprocessor controlled prosthetic knees (MPK) offer opportunities for improved walking stability and function, but some devices' swing phase features may exceed needs of users with invariable cadence. One MPK offers computerized control of only stance (C-Leg Compact).


OBJECTIVE
To assess Medicare Functional Classification Level K2 walkers' ramp negotiation performance, function and balance while using a non-MPK (NMPK) compared to the C-Leg Compact.


METHODS
Crossover.


METHODS
Gait while ascending and descending a ramp (stride characteristics, kinematics, electromyography) and function were assessed in participant's existing NMPK and again in the C-Leg Compact following accommodation.


RESULTS
Ramp ascent and descent were markedly faster in the C-Leg Compact compared to the NMPK (p ≤ 0.006), owing to increases in stride length (p ≤ 0.020) and cadence (p ≤ 0.020). Residual limb peak knee flexion and ankle dorsiflexion were significantly greater (12.9° and 4.9° more, respectively) during single limb support while using the C-Leg Compact to descend ramps. Electromyography (mean, peak) did not differ significantly between prosthesis. Function improved in the C-Leg Compact as evidenced by a significantly faster Timed Up and Go and higher functional questionnaire scores.


CONCLUSIONS
Transfemoral K2 walkers exhibited significantly improved function and balance while using the stance-phase only MPK compared to their traditional NMPK.
Madonna Rehabilitation Hospital, Lincoln, NE, USA.
Judith M
JM
Burnfield
Valerie J
VJ
Eberly
Joanne K
JK
Gronely
Jacquelin
J
Perry
William Jared
WJ
Yule
Sara J
SJ
Mulroy
D000368:Aged; D000674:Amputees / Q000145:classification / Q000534:rehabilitation*; D001107:Architectural Accessibility; D001696:Biomechanical Phenomena / Q000502:physiology; D018592:Cross-Over Studies; D004576:Electromyography; D005260:Female; D005269:Femur / Q000601:surgery*; D005684:Gait / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D007720:Knee Prosthesis / Q000145:classification*; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology; D013997:Time Factors; D016138:Walking / Q000502:physiology*