title: [Fall risk assessment and knee extensor muscle activity in elderly people].
abstract: OBJECTIVE
  The purpose of this study was to analyze relationships between the history of falls, tripping, sway, and knee extensor muscle strengths as a tool for fall risk assessment in elderly people. We examined effective fall prevention measures.
  
  
  METHODS
  We investigated 102 elderly volunteers in the community. The subjects were classified according to history of falls, tripping, sway and 5 performance tests conducted to assess fall risk including Timed up-and-go test (TUG), Functional Reach test (FR), Hand grip and Reaction time (RT). In addition, the time serial data of the knee extensor muscle strength were acquired using a hand-held dynamometer.
  
  
  RESULTS
  In comparison to the non-faller group, the faller group showed a significantly higher incident rate of tripping and sway. A frequency analysis using the Maximum Entropy Method revealed that the fallers group showed lower peak frequency (p=0.025). Also, the slope of the logarithmical spectrum was less steep in the fallers group (p=0.035). Also results from analysis of the peak force latency from the beginning of measurement to 50%, 80%, and 100% muscle strength, also showed that the faller group took more time for maximal voluntary contraction.
  
  
  CONCLUSIONS
  The frequency analysis of the time series date of peak force latency of knee extensor muscle strength revealed that the muscle activity differs in faller compared to non-fallers. This study suggested that knee extensor muscle isometric performance could possibly be used as a new tool for fall risk assessment. We concluded that exercises to raise maximal muscle strength and muscle response speed are useful for the prevention of falls.
authors.affiliation: Graduate School of Medicine, Saga University.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Oya
authors.forename: Masumi
authors.initials: M
authors.lastname: Nakamura
authors.forename: Emi
authors.initials: E
authors.lastname: Tabata
authors.forename: Ryo
authors.initials: R
authors.lastname: Morizono
authors.forename: Sachiko
authors.initials: S
authors.lastname: Mori
authors.forename: Yukari
authors.initials: Y
authors.lastname: Kimuro
authors.forename: Etsuo
authors.initials: E
authors.lastname: Horikawa
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D000368:Aged; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D018570:Risk Assessment