title: Analysis of vertical ground reaction force variables during a Sit to Stand task in participants recovering from a hip fracture.
abstract: BACKGROUND
  A Sit to Stand task following a hip fracture may be achieved through compensations (e.g. bilateral arms and uninvolved lower extremity), not restoration of movement strategies of the involved lower extremity. The primary purpose was to compare upper and lower extremity movement strategies using the vertical ground reaction force during a Sit to Stand task in participants recovering from a hip fracture to control participants. The secondary purpose was to evaluate the correlation between vertical ground reaction force variables and validated functional measures.
  
  
  METHODS
  Twenty eight community dwelling older adults, 14 who had a hip fracture and 14 control participants completed the Sit to Stand task on an instrumented chair designed to measure vertical ground reaction force, performance based tests (Timed up and go, Berg Balance Scale and Gait Speed) and a self report Lower Extremity Measure. A MANOVA was used to compare functional scales and vertical ground reaction force variables between groups. Bivariate correlations were assessed using Pearson Product Moment correlations.
  
  
  RESULTS
  The vertical ground reaction force variables showed significantly higher bilateral arm force, higher uninvolved side peak force and asymmetry between the involved and uninvolved sides for the participants recovering from a hip fracture (Wilks' Lambda=3.16, P=0.019). Significant correlations existed between the vertical ground reaction force variables and validated functional measures.
  
  
  CONCLUSIONS
  Participants recovering from a hip fracture compensated using their arms and the uninvolved side to perform a Sit to Stand. Lower extremity movement strategies captured during a Sit to Stand task were correlated to scales used to assess function, balance and falls risk.
authors.affiliation: Department of Physical Therapy, Ithaca College Rochester Center, 1100 South Goodman St., Rochester, NY 14618, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: Houck
authors.forename: Janet
authors.initials: J
authors.lastname: Kneiss
authors.forename: Susan V
authors.initials: SV
authors.lastname: Bukata
authors.forename: J Edward
authors.initials: JE
authors.lastname: Puzas
mesh_terms: D000368:Aged; D003198:Computer Simulation; D005260:Female; D005264:Femoral Fractures / Q000503:physiopathology* / Q000628:therapy*; D005528:Foot / Q000503:physiopathology*; D017102:Fracture Healing; D006801:Humans; D008297:Male; D008954:Models, Biological; D004856:Postural Balance; D011187:Posture; D020127:Recovery of Function; D013314:Stress, Mechanical; D016896:Treatment Outcome