title: Effects of a modified shoe on knee load in people with and those without knee osteoarthritis.
abstract: OBJECTIVE
  To evaluate the effects of a modified shoe that incorporates both lateral wedging and a variable-stiffness sole on knee joint loading in 3 populations: individuals with symptomatic and radiographic knee osteoarthritis (OA), asymptomatic overweight individuals, and asymptomatic healthy weight individuals.
  
  
  METHODS
  Ninety participants (30 per group) underwent a 3-dimensional gait analysis across 3 test conditions: modified shoes, standard control shoes, and barefoot. For each condition, the first peak knee adduction moment (KAM) and knee flexion moment (KFM) (both expressed as Nm/[body weight × height]%) as well as the KAM impulse (expressed as Nm.s/[body weight × height]%) were determined.
  
  
  RESULTS
  The modified shoes significantly reduced the peak KAM as compared to the control shoes in both the OA (P = 0.002) and the overweight (P = 0.03) groups. In the OA group, there was no significant difference in peak KAM when walking in the modified shoe as compared to walking barefoot. In the overweight and the healthy weight groups, the peak KAM when walking in the modified shoe was significantly higher than that when walking barefoot (P < 0.001). Irrespective of group, the KAM impulse was significantly reduced when walking in the modified shoe as compared to the control shoe (P < 0.001) and was significantly higher during both shoe conditions as compared to walking barefoot (P < 0.001). There was no change in the KFM between walking conditions for any group.
  
  
  CONCLUSIONS
  The findings illustrate that a shoe incorporating both a lateral wedge and a variable-stiffness sole can significantly reduce medial knee joint load. Further research examining the effects of these shoes on pain, function, and structural changes in the joint is warranted.
authors.affiliation: University of Melbourne, Parkville, Victoria, Australia. k.bennell@unimelb.edu.au
authors.forename: Kim L
authors.initials: KL
authors.lastname: Bennell
authors.forename: Crystal O
authors.initials: CO
authors.lastname: Kean
authors.forename: Tim V
authors.initials: TV
authors.lastname: Wrigley
authors.forename: Rana S
authors.initials: RS
authors.lastname: Hinman
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D015992:Body Mass Index; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D009989:Orthotic Devices; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D050177:Overweight / Q000503:physiopathology; D011859:Radiography; D012775:Shoes; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology