title: Swing limb mechanics and minimum toe clearance in people with knee osteoarthritis.
abstract: OBJECTIVE
  Knee osteoarthritis (OA) has been shown to be a risk factor for falls. Reductions in foot clearance during the swing phase of walking can cause a trip and potentially lead to a fall. This study examined the swing phase mechanics of people with and without knee OA during walking.
  
  
  METHODS
  Minimum toe clearance (MTC) height, joint angles at the time of MTC and the influence of the angular changes of the hip, knee and ankle of the swing leg on foot clearance using sensitivity analysis were investigated in 50 knee OA participants and 28 age-matched asymptomatic controls.
  
  
  RESULTS
  Although both groups had a similar MTC height (controls: 12.8±6.7 mm, knee OA: 13.4±7.0 mm), the knee OA group used a different strategy to achieve the same foot clearance, as evidenced by greater knee flexion (52.5±5.3° vs 49.4±4.8°, p=0.007), greater hip abduction (-3.6±3.3° vs -1.8±3.3°, p=0.03) and less ankle adduction (2.8±1.9° vs 4.2±2.1°, p=0.01).
  
  
  CONCLUSIONS
  MTC height was comparable between the groups, however a different swing phase mechanism was used by the knee OA. Although adequate MTC is an important component of safe locomotion, it does not appear to be impaired in people with knee OA. Other factors, such as inadequate responses to postural perturbation, may be responsible for falls in this group.
authors.affiliation: Musculoskeletal Research Centre, Faculty of Health Sciences, La Trobe University, Bundoora, Victoria 3086, Australia. p.levinger@latrobe.edu.au
authors.forename: Pazit
authors.initials: P
authors.lastname: Levinger
authors.forename: Daniel T H
authors.initials: DT
authors.lastname: Lai
authors.forename: Hylton B
authors.initials: HB
authors.lastname: Menz
authors.forename: Adam D
authors.initials: AD
authors.lastname: Morrow
authors.forename: Julian A
authors.initials: JA
authors.lastname: Feller
authors.forename: John R
authors.initials: JR
authors.lastname: Bartlett
authors.forename: Neil R
authors.initials: NR
authors.lastname: Bergman
authors.forename: Rezaul
authors.initials: R
authors.lastname: Begg
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control / Q000706:statistics & numerical data*; D000368:Aged; D000886:Anthropometry; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005528:Foot / Q000502:physiology; D005684:Gait / Q000502:physiology; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014033:Toe Joint / Q000503:physiopathology*; D016138:Walking / Q000502:physiology*