title: Relationship between hip abductor strength and external hip and knee adduction moments in medial knee osteoarthritis.
abstract: BACKGROUND
  Alterations in hip abductor strength and hip and knee adduction moments during gait are associated with knee osteoarthritis. This study examines the relationship between hip abductor strength and hip and knee adduction moments during gait in individuals with symptomatic medial knee osteoarthritis.
  
  
  METHODS
  Ninety-nine participants underwent maximal isometric hip abductor strength testing and 3D gait analysis. Pearson correlations examined relationships between non-normalized maximal hip abductor strength (Nm), peak external hip and knee adduction moments (Nm) and knee adduction moment impulse (Nm∙s). Linear regressions examined these relationships while controlling for body size (height and mass) and walking speed.
  
  
  RESULTS
  Positive relationships existed between non-normalized hip abductor strength and hip and knee adduction moments (r=0.28 and 0.37, respectively, p<0.01) as well as the knee adduction moment impulse (r=0.47, p<0.01). However, after controlling for body size and walking speed, hip abductor strength was not a significant predictor of hip or knee adduction moments (B=-0.08, and 0.04, respectively, p>0.05) but was a significant predictor of knee adduction moment impulse (B=0.05, p=0.005), explaining 6% of the variance.
  
  
  CONCLUSIONS
  While a significant relationship between hip abductor strength and knee adduction moment impulse was noted, hip abductor strength only explained a small amount of variance in the impulse. Our findings support previous research of healthy individuals and those with mild to moderate knee osteoarthritis and suggests hip abductor strength has little influence on hip and knee adduction moments during gait.
authors.affiliation: School of Medical and Applied Sciences, CQUniversity, Rockhampton, Queensland, Australia; Centre for Health, Exercise and Sports Medicine (CHESM), Department of Physiotherapy, The University of Melbourne, Victoria, Australia. Electronic address: c.kean@cqu.edu.au.
authors.forename: Crystal O
authors.initials: CO
authors.lastname: Kean
authors.affiliation: Centre for Health, Exercise and Sports Medicine (CHESM), Department of Physiotherapy, The University of Melbourne, Victoria, Australia.
authors.forename: Kim L
authors.initials: KL
authors.lastname: Bennell
authors.affiliation: Centre for Health, Exercise and Sports Medicine (CHESM), Department of Physiotherapy, The University of Melbourne, Victoria, Australia.
authors.forename: Tim V
authors.initials: TV
authors.lastname: Wrigley
authors.affiliation: Centre for Health, Exercise and Sports Medicine (CHESM), Department of Physiotherapy, The University of Melbourne, Victoria, Australia.
authors.forename: Rana S
authors.initials: RS
authors.lastname: Hinman
mesh_terms: D049628:Body Size; D005260:Female; D005684:Gait / Q000502:physiology; D006615:Hip / Q000503:physiopathology*; D006801:Humans; D007717:Knee / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D016138:Walking
keywords: Adduction moment; Hip; Knee; Muscle strength; Osteoarthritis