Physical performance and self-report outcomes associated with use of passive, adaptive, and active prosthetic knees in persons with unilateral, transfemoral amputation: Randomized crossover trial

Abstract

Abstract-Prosthetic knees are a vital component in an artificial limb. Contemporary knees include passive (mechanical), adaptive (computerized), or active (motorized) control systems and have the potential to mitigate amputation-related functional impairments and activity limitations. A 14 mo randomized crossover trial was conducted. Participants (n = 12, mean age = 58 yr) were tested under three conditions: passive control (existing knee), adaptive control (Ossur Rheo Knee II), and active control (Ossur Power Knee II). Training and acclimation time were provided to participants in the adaptive and active knees. Outcome measures included indoor tests (Timed Up and Go test [TUG], stairs, and ramp), outdoor tests (walking course and perceived exertion), step activity monitor, self-report surveys (mobility, balance confidence, physical function, fatigue, and general health), and fall incidence. Mixed-effects linear regression modeling was used to evaluate data. Compared with passive control, adaptive control significantly improved comfortable TUG time (difference = 0.91 s, p = 0.001) and reported physical function (difference = 1.26 [T-score], p = 0.03). Active control significantly increased comfortable TUG, fast TUG, and ramp times (difference = 3.02, 2.66, and 0.96 s, respectively, all p < 0.03) and increased balance confidence (difference = 3.77, p = 0.003) compared with passive control. Findings suggest that adaptive knee control may enhance function compared with passive control but that active control can restrict mobility in middle-age or older users with transfemoral amputation.

Adapting to change : influence if a microprocessor-controlled prosthetic knee on gait adaptations

“…There is also ambiguity when looking at the time needed to descent a slope. Both a decrease 27,36 as an increase in time 34 have been reported while using a MPK compared to the use of a NMPK.…”

“…Hafner et al 34 found no differences in walking speed, whereas Meier et al 35 found an increase in walking speed while using a MPK to navigate an obstacle course.…”

“…22 Three studies have been published after October 2009 that compared the use of MPKs and NMPKs while descending a slope. 34,36,37 The results of these studies could be combined with one previously conducted trial 27 which was omitted by Sawers and Hafner 22 as it was the only available study that used the Hill Assessment Index at that time. There is ambiguity in results when looking at qualitative aspects of slope descent (e.g.…”

“…27,32 Finally, there is moderate evidence that the use of stance and swing MPKs result in increased subject-reported confidence while walking when compared with the use of NMPKs. 27,32,38,39 Two trials 34,36 have been published studying aspects of safety after the search strategy of the review of Sawers and Hafner was completed. The trial of Hafner et al 34 found no statistical significant difference in subject-reported confidence between the use of a MPK or a NMPK.…”

“…27,32,38,39 Two trials 34,36 have been published studying aspects of safety after the search strategy of the review of Sawers and Hafner was completed. The trial of Hafner et al 34 found no statistical significant difference in subject-reported confidence between the use of a MPK or a NMPK. This result is in contrast to the results of the included studies by Sawers and Hafner.…”