title: Objective measurement of stiffness in knee osteoarthritis.
abstract: OBJECTIVE
  The purpose of this study was to evaluate an objective measure of knee joint stiffness in older adults with and without knee osteoarthritis.
  
  
  METHODS
  Methodological study of the modified pendulum test.
  
  
  METHODS
  A convenience sample of community-dwelling older adults (n = 41).
  
  
  METHODS
  Knee angle oscillation data were collected with a VICON motion analysis system and were used to calculate stiffness and damping coefficients and measures of joint stiffness.
  
  
  RESULTS
  Although some testing problems were encountered early in the study, useable data were obtained from 29 participants. Within-participant variability for calculated stiffness and damping coefficients was low (0.55% and 8.92%, respectively), whereas the between-participant variability was high for both the stiffness (99.45%) and damping (91.08%) coefficients.
  
  
  CONCLUSIONS
  The modified pendulum test is a reliable method for evaluation of knee joint stiffness. This method can be used in collection of outcome data for future intervention studies addressing joint stiffness.
authors.affiliation: Sinclair School of Nursing, University of Missouri-Columbia, Missouri, USA.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Burks
authors.forename: Kevin
authors.initials: K
authors.lastname: Keegan
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D002138:Calibration; D016022:Case-Control Studies; D004548:Elasticity; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D015146:Midwestern United States; D009991:Oscillometry / Q000379:methods* / Q000592:standards; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000503:physiopathology; D016059:Range of Motion, Articular; D011795:Surveys and Questionnaires; D014743:Videotape Recording / Q000379:methods* / Q000592:standards