title: The influence of a user-adaptive prosthetic knee across varying walking speeds: A randomized cross-over trial.
abstract: Previously conducted trials comparing the gait pattern of individuals with a transfemoral amputation using a user-adaptive and a non-microprocessor-controlled prosthetic knee (NMPK) found mixed and conflicting results. Few trials, however, have compared user-adaptive to non-adaptive prosthetic knees across different walking speeds. Because of the ability of variable damping, the effect of user-adaptive knees might be more pronounced at lower or higher walking speeds. Our aim was to compare the Rheo Knee II (a microprocessor-controlled prosthetic knee) with NMPKs across varying walking speeds. In addition, we studied compensatory mechanisms associated with non-optimal prosthetic knee kinematics, such as intact ankle vaulting and vertical acceleration of the pelvis. Nine persons with a transfemoral amputation or knee disarticulation were included and measured with their own NMPK and with the Rheo Knee II. Measurements were performed at three walking speeds: preferred walking speed, 70% preferred walking speed and 115% preferred walking speed. No differences on peak prosthetic knee flexion during swing were found between prosthetic knee conditions. In addition, prosthetic knee flexion increased significantly with walking speed for both prosthetic knee conditions. At 70% preferred walking speed we found that vaulting of the intact ankle was significantly decreased while walking with the Rheo Knee II compared to the NMPK condition (P=0.028). We did not find differences in peak vertical acceleration of the pelvis during initial and mid-swing of the prosthetic leg. In conclusion, comparison of walking with the Rheo Knee II to walking with a NMPK across different walking speeds showed limited differences in gait parameters.
authors.affiliation: Roessingh Research and Development P.O. Box 310, 7500 AH Enschede, The Netherlands; University of Twente MIRA research institute for Biomedical Technology and Technical Medicine Department of Biomechanical Engineering P. O. Box 217, 7500 AE Enschede, The Netherlands. Electronic address: e.prinsen@rrd.nl.
authors.forename: E C
authors.initials: EC
authors.lastname: Prinsen
authors.affiliation: Roessingh Research and Development P.O. Box 310, 7500 AH Enschede, The Netherlands; Roessingh, Center for Rehabilitation P.O. Box 310 7500 AE Enschede, The Netherlands. Electronic address: m.nederhand@rrd.nl.
authors.forename: M J
authors.initials: MJ
authors.lastname: Nederhand
authors.affiliation: University of Twente MIRA research institute for Biomedical Technology and Technical Medicine Department of Biomechanical Engineering P. O. Box 217, 7500 AE Enschede, The Netherlands. Electronic address: hildurs08@ru.is.
authors.forename: H S
authors.initials: HS
authors.lastname: Sveinsdóttir
authors.affiliation: Military Rehabilitation Centre 'Aardenburg' Department Research and Development P.O. Box 185, 3940 AD Doorn, The Netherlands. Electronic address: mr.prins@mrcdoorn.nl.
authors.forename: M R
authors.initials: MR
authors.lastname: Prins
authors.affiliation: Military Rehabilitation Centre 'Aardenburg' Department Research and Development P.O. Box 185, 3940 AD Doorn, The Netherlands. Electronic address: meer@mrcdoorn.nl.
authors.forename: F
authors.initials: F
authors.lastname: van der Meer
authors.affiliation: University of Twente MIRA research institute for Biomedical Technology and Technical Medicine Department of Biomechanical Engineering P. O. Box 217, 7500 AE Enschede, The Netherlands. Electronic address: h.f.j.m.koopman@utwente.nl.
authors.forename: H F J M
authors.initials: HFJM
authors.lastname: Koopman
authors.affiliation: Roessingh Research and Development P.O. Box 310, 7500 AH Enschede, The Netherlands; University of Twente MIRA research institute for Biomedical Technology and Technical Medicine Department of Biomechanical Engineering P. O. Box 217, 7500 AE Enschede, The Netherlands; Roessingh, Center for Rehabilitation P.O. Box 310 7500 AE Enschede, The Netherlands. Electronic address: j.s.rietman@rrd.nl.
authors.forename: J S
authors.initials: JS
authors.lastname: Rietman
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D018592:Cross-Over Studies; D005260:Female; D005684:Gait; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D016896:Treatment Outcome; D016138:Walking; D000072797:Walking Speed; D055815:Young Adult
keywords: Adaptations; Gait analysis; Knee; Microprocessor-controlled prosthetic; Transfemoral amputation; Walking