title: Weight-bearing asymmetry during sit-stand transitions related to impairment and functional mobility after total knee arthroplasty.
abstract: OBJECTIVE
  To examine changes in weight-bearing (WB) asymmetry during sit-stand transitions for individuals during the first 6 months after unilateral total knee arthroplasty (TKA). Relationships between WB asymmetry, clinical measures of knee impairment, and functional mobility also were evaluated.
  
  
  METHODS
  Prospective repeated-measures design.
  
  
  METHODS
  Clinical research laboratory.
  
  
  METHODS
  People (N=36) with knee osteoarthritis (OA) scheduled to undergo unilateral TKA and a control (CTL) group (N=17 healthy people) were enrolled.
  
  
  METHODS
  The TKA group participated in acute, home, and outpatient phases of exercise-based rehabilitation.
  
  
  METHODS
  WB asymmetry measured during a 5-Times Sit-to-Stand Test (FTSST) based on average vertical ground reaction force under each foot, self-reported knee pain using a numerical pain rating scale, knee active range of motion symmetry, knee extensor strength symmetry, FTSST time, 6-minute walk test distance, and Stair Climbing Test time.
  
  
  RESULTS
  Compared with preoperative values, the TKA group showed greater WB asymmetry at 1 month after surgery (P<.001). By 6 months, the TKA group had less WB asymmetry than preoperative values (P<.001), which was not different from the CTL group. Symmetry in WB correlated with functional outcomes and symmetry of quadriceps strength for the TKA group 6 months postoperatively.
  
  
  CONCLUSIONS
  Patients with unilateral knee OA showed WB asymmetry during sit-stand transitions early after unilateral TKA that improved by 6 months after surgery and was no different from that for healthy people of similar age. For people in the first 6 months after TKA, greater symmetry was related to better function and strength symmetry.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Colorado, Aurora, CO, USA. cory.christiansen@ucdenver.edu
authors.forename: Cory L
authors.initials: CL
authors.lastname: Christiansen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bade
authors.forename: Dana L
authors.initials: DL
authors.lastname: Judd
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Stevens-Lapsley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D016022:Case-Control Studies; D004185:Disability Evaluation; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010147:Pain Measurement; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function; D016474:Weight-Bearing / Q000502:physiology*