title: Biomechanical properties of shoes and risk of falls in older adults.
abstract: OBJECTIVE
  To determine the relationships between the biomechanical properties of shoes worn in a cohort of healthy older adults and the risk of falling.
  
  
  METHODS
  Nested case-control study, comparing biomechanical measurements of shoes worn by those who reported a fall with measurements of shoes worn by age- and sex-matched nonfallers engaged in broadly similar activities.
  
  
  METHODS
  On-site measurements where falls occurred.
  
  
  METHODS
  A cohort of 1,371 older adults, of whom 327 reported a fall and 327 served as age- and sex-matched controls.
  
  
  METHODS
  Shoe measurements related to lateral stability (heel height and width, critical tipping angle), foot position sense (heel-collar height, sole thickness, and sole flexibility), and the shoe/surface interface (foresole material, shoe-to-ground coefficient of friction, sole contact area).
  
  
  RESULTS
  Greater heel height was associated with increased risk of a fall (P for trend=.03), whereas greater sole contact area was associated with reduced risk (P for trend=.005). Shoe characteristics related to foot position sense bore little apparent relation to fall risk. Coefficients of friction of 0.5 or greater were observed in 93% of shoes measured, indicating that very few were excessively slippery.
  
  
  CONCLUSIONS
  Certain measurable properties of shoes were found to be significantly related to risk of falls in older adults. Wearing shoes with low heels and large contact area may help older adults reduce the risk of a fall in everyday settings and activities.
authors.affiliation: Harborview Injury Prevention and Research Center, Orthopedic Sciences Laboratory, Harborview Medical Center, MS 359798, 325 Ninth Avenue, Seattle, WA 98104, USA. atencer@u.washington.edu
authors.forename: Allan F
authors.initials: AF
authors.lastname: Tencer
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Koepsell
authors.forename: Marsha E
authors.initials: ME
authors.lastname: Wolf
authors.forename: Cara L
authors.initials: CL
authors.lastname: Frankenfeld
authors.forename: David M
authors.initials: DM
authors.lastname: Buchner
authors.forename: Walter A
authors.initials: WA
authors.lastname: Kukull
authors.forename: Andrea Z
authors.initials: AZ
authors.lastname: LaCroix
authors.forename: Eric B
authors.initials: EB
authors.lastname: Larson
authors.forename: Milda
authors.initials: M
authors.lastname: Tautvydas
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004867:Equipment Design; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D016015:Logistic Models; D008297:Male; D004856:Postural Balance; D012307:Risk Factors; D012775:Shoes / Q000009:adverse effects* / Q000706:statistics & numerical data; D016138:Walking