title: Alternatives for measuring knee extension strength of the elderly at home.
abstract: OBJECTIVE
  To examine the construct validity of three measures of knee extension strength obtained from elderly individuals.
  
  
  METHODS
  Retrospective and cross-sectional.
  
  
  METHODS
  Home care.
  
  
  METHODS
  Forty-one consecutively treated patients (mean age 79.2 years).
  
  
  METHODS
  Knee extension strength was measured using manual muscle testing, hand-held dynamometry, and the sit-to-stand test.
  
  
  RESULTS
  Convergent construct validity was supported by the significant correlations between the measures (rs = 0.578-0.702). Discriminant construct validity was confirmed by the finding of significant differences in the manual muscle test scores and in the hand-held dynamometer measures of patients who were unable versus able to stand from a chair without the upper extremities or help. The sensitivity of the two measures for discriminating between patients able versus unable to stand from a chair was 90.9% for manual testing and 68.2% for dynamometry. The specificity was 78.9% for manual testing and 94.7% for dynamometry.
  
  
  CONCLUSIONS
  The results of this study show that the three measures employed to characterize knee extension strength are valid when employed with elderly patients in a home care setting.
authors.affiliation: Department of Physical Therapy, School of Allied Health, University of Connecticut, Storrs 06269, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Bohannon
mesh_terms: D000368:Aged; D005260:Female; D006699:Home Care Services; D006801:Humans; D007717:Knee / Q000502:physiology*; D008297:Male; D008722:Methods; D018482:Muscle, Skeletal / Q000502:physiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity