title: Quadriceps function, proprioceptive acuity and functional performance in healthy young, middle-aged and elderly subjects.
abstract: BACKGROUND
  Muscle functions to generate force-producing movement and also has a role in proprioception. If ageing compromises these sensorimotor functions of muscle, the ability of older subjects to detect and correct postural sway may be impeded, resulting in impairment of functional performance.
  
  
  METHODS
  To see if age-related changes occurred and, if so, what their effects might be. Quadriceps strength, proprioception, postural stability and functional performance were assessed in young (n = 20, mean age 23 years), middle-aged (n = 10, mean age 56 years) and elderly (n = 15, mean age 72 years) subjects.
  
  
  RESULTS
  With increasing age there were decreases in quadriceps strength (r = -0.511; P < 0.001), acuity of joint position sense (r = -0.603; P < 0.001) and postural stability (ANOVA < 0.002) during stance conditions which placed a greater reliance on muscle proprioceptors. These changes may decrease postural stability confidence, resulting in impaired performance of common activities of daily living (r = 0.635; P < 0.001).
  
  
  CONCLUSIONS
  The age-related deterioration in sensorimotor function of muscle may contribute to the increased fear and frequency of falls in elderly subjects, thereby decreasing independence.
authors.affiliation: Kings College London, Rehabilitation Research Unit, Dulwich Hospital, UK. m.hurley@kcl.ac.uk
authors.forename: M V
authors.initials: MV
authors.lastname: Hurley
authors.forename: J
authors.initials: J
authors.lastname: Rees
authors.forename: D J
authors.initials: DJ
authors.lastname: Newham
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D011187:Posture / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*