title: Kinetic asymmetry in transfemoral amputees while performing sit to stand and stand to sit movements.
abstract: Transitional movements are a determinant of functional independence and have limited study in amputees. Microprocessor prosthetic knees' abilities to assist transfemoral amputees with sitting and standing have not been studied. Through cross-sectional study, 21 transfemoral amputees, divided into 3 groups of 7 by knee type (power knee, C-leg, Mauch SNS) and 7 non-amputee controls (n=28) performed sit to stand and stand to sit while kinematic and kinetic data were recorded. Transfemoral amputees can stand (1.6-2.0s) and sit (2.1-2.8s) at rates comparable to controls (1.6s). Controls' ground reaction force (GRF) and knee moment production was <7% asymmetric and superior to amputees' during both movements. For sit to stand, amputees' asymmetry for GRF ranged from 53 to 69% and 110 to 124% for knee moments. For stand to sit, amputees' asymmetry for GRF ranged from 32 to 60% and 84 to 114% for knee moments. Hip moment asymmetry for sit to stand was less for control (21%) and power knee (34%) groups than that produced by the Mauch SNS (59%) group. For stand to sit, hip moment production for the Mauch SNS (47%) and C-leg groups (71%) were more asymmetric than controls (19%). In the majority of cases transfemoral amputees do not load their prosthesis extensively for standing up or sitting down. Therefore, this transitional movement is currently a one-legged task, which increases stress on the sound limb. Generally, the prosthetic knees studied did not produce a significant knee moment in either task. Although most differences between knee groups were not statistically significant, differences may be clinically meaningful on an individual basis.
authors.affiliation: University of South Florida, College of Medicine, School of Physical Therapy & Rehabilitation Sciences, Tampa, FL, United States; HSRD/RR&D Center of Excellence. James A. Haley Veterans' Administration Hospital, Tampa, FL, United States. mhighsmi@health.usf.edu
authors.forename: M Jason
authors.initials: MJ
authors.lastname: Highsmith
authors.forename: Jason T
authors.initials: JT
authors.lastname: Kahle
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Carey
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Lura
authors.forename: Rajiv V
authors.initials: RV
authors.lastname: Dubey
authors.forename: Kristine R
authors.initials: KR
authors.lastname: Csavina
authors.forename: William S
authors.initials: WS
authors.lastname: Quillen
mesh_terms: D000328:Adult; D000368:Aged; D000674:Amputees; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*