title: Between-limb kinematic asymmetry during gait in unilateral and bilateral mild to moderate knee osteoarthritis.
abstract: OBJECTIVE
  To compare lower-limb kinematic asymmetries during gait in individuals with unilateral and bilateral symptomatic osteoarthritis and controls.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Participants (N=54) had symptomatic unilateral (n=18) or bilateral (n=18) knee osteoarthritis. Healthy controls were sex- and age-matched and similar in height and weight to osteoarthritis groups (n=18).
  
  
  METHODS
  Three-dimensional motion analysis was conducted while participants walked on a treadmill at 1.1m/s.
  
  
  METHODS
  Maximum joint angles and velocities of the knee and hip during stance, knee flexion, knee adduction, and hip adduction at initial contact, pelvic drop, stride length, and average toe out.
  
  
  RESULTS
  There was a significant limb effect for knee flexion at initial contact (P=.01). The bilateral osteoarthritis group demonstrated the largest between-limb asymmetry (2.83°; 95% confidence interval, .88-4.78; effect size [ES]=.67). The bilateral osteoarthritis group also displayed tendencies toward between-limb asymmetry in hip adduction at initial contact and peak knee adduction during stance; ESs were small (ES=.33 and .48). Lower-limb kinematics was symmetrical in the control and unilateral knee osteoarthritis groups.
  
  
  CONCLUSIONS
  Between-limb asymmetries are present even at mild to moderate stages of knee osteoarthritis. During this stage, between-limb asymmetry appears to be more prevalent in patients with bilateral symptomatic disease, suggesting that patients with unilateral disease maintain kinematic symmetry for longer in the knee osteoarthritis process. Further, early treatment strategies should target the restoration of gait symmetry and involve kinematics changes in both lower limbs. Future research is needed to determine the efficacy of such strategies with respect to kinematic asymmetry, pain, and disease progression.
authors.affiliation: Running Injury Clinic, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Mills
authors.forename: Blayne A
authors.initials: BA
authors.lastname: Hettinga
authors.forename: Michael B
authors.initials: MB
authors.lastname: Pohl
authors.forename: Reed
authors.initials: R
authors.lastname: Ferber
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009568:Nitrendipine; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000534:rehabilitation
chemical_list: D009568:Nitrendipine
keywords: 3-dimensional; 3D; Biomechanics; CI; ES; IC; KOOS; Knee; Knee Osteoarthritis Outcome Survey; OA; Osteoarthritis; Rehabilitation; VAS; Walking; confidence interval; effect size; initial contact; osteoarthritis; visual analog scale