title: Effects of common footwear on joint loading in osteoarthritis of the knee.
abstract: OBJECTIVE
  Elevated joint loads during walking have been associated with the severity and progression of osteoarthritis (OA) of the knee. Footwear may have the potential to alter these loads. This study compares the effects of several common shoe types on knee loading in subjects with OA of the knee.
  
  
  METHODS
  Thirty-one subjects (10 men, 21 women) with radiographic and symptomatic knee OA underwent gait analyses using an optoelectronic camera system and multicomponent force plate. In each case, gait was evaluated during barefoot walking and while wearing 4 different shoe types: 1) clogs, 2) stability shoes, 3) flat walking shoes, and 4) flip-flops. Peak knee loads were compared between the different footwear conditions.
  
  
  RESULTS
  Overall, the clogs and stability shoes resulted in a significantly higher (approximately 15% higher) peak knee adduction moment (mean +/- SD 3.1 +/- 0.7 and 3.0 +/- 0.7 divided by body weight [BW] x height [H] multiplied by 100, respectively; P < 0.05) compared with that of flat walking shoes (mean +/- SD 2.8 +/- 0.7 %BW x H), flip-flops (mean +/- SD 2.7 +/- 0.8 %BW x H), and barefoot walking (mean +/- SD 2.7 +/- 0.7 %BW x H). There were no statistically significant differences in knee loads with the flat walking shoes and flip-flops compared with barefoot walking.
  
  
  CONCLUSIONS
  These data confirm that footwear may have significant effects on knee loads during walking in subjects with OA of the knee. Flexibility and heel height may be important differentiating characteristics of shoes that affect knee loads. In light of the strong relationship between knee loading and OA, the design and biomechanical effects of modern footwear should be more closely evaluated in terms of their effects on the disease.
authors.affiliation: Section of Rheumatology, Rush Medical College, Chicago, Illinois 60612-4861, USA. najia_shakoor@rush.edu
authors.forename: Najia
authors.initials: N
authors.lastname: Shakoor
authors.forename: Mondira
authors.initials: M
authors.lastname: Sengupta
authors.forename: Kharma C
authors.initials: KC
authors.lastname: Foucher
authors.forename: Markus A
authors.initials: MA
authors.lastname: Wimmer
authors.forename: Louis F
authors.initials: LF
authors.lastname: Fogg
authors.forename: Joel A
authors.initials: JA
authors.lastname: Block
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D016059:Range of Motion, Articular; D012775:Shoes / Q000009:adverse effects*; D016474:Weight-Bearing