title: The Gait Deviation Index Is Associated with Hip Muscle Strength and Patient-Reported Outcome in Patients with Severe Hip Osteoarthritis-A Cross-Sectional Study.
abstract: BACKGROUND
  The Gait Deviation Index summarizes overall gait 'quality', based on kinematic data from a 3-dimensional gait analysis. However, it is unknown which clinical outcomes may affect the Gait Deviation Index in patients with primary hip osteoarthritis. The aim of this study was to investigate associations between Gait Deviation Index as a measure of gait 'quality' and hip muscle strength and between Gait Deviation Index and patient-reported outcomes in patients with primary hip osteoarthritis.
  
  
  METHODS
  Forty-seven patients (34 males), aged 61.1 ± 6.7 years, with BMI 27.3 ± 3.4 (kg/m2) and with severe primary hip osteoarthritis underwent 3-dimensional gait analysis. Mean Gait Deviation Index, pain after walking and maximal isometric hip muscle strength (flexor, extensor, and abductor) were recorded. All patients completed the 'Physical Function Short-form of the Hip disability and Osteoarthritis Outcome Score (HOOS-Physical Function) and the Hip disability and Osteoarthritis Outcome Score subscales for pain (HOOS-Pain) and quality-of-life (HOOS-QOL).
  
  
  RESULTS
  Mean Gait Deviation Index was positively associated with hip abduction strength (p<0.01, r = 0.40), hip flexion strength (p = 0.01, r = 0.37), HOOS-Physical Function (p<0.01, r = 0.41) HOOS-QOL (p<0.01, r = 0.41), and negatively associated with HOOS-Pain after walking (p<0.01, r = -0.45). Adjusting the analysis for walking speed did not affect the association.
  
  
  CONCLUSIONS
  Patients with the strongest hip abductor and hip flexor muscles had the best gait 'quality'. Furthermore, patients with higher physical function, quality of life scores and lower pain levels demonstrated better gait 'quality'. These findings indicate that interventions aimed at improving hip muscle strength and pain management may to a moderate degree improve the overall gait 'quality' in patients with primary hip OA.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark.|Department of Orthopaedic Surgery and Traumatology, Køge Hospital, Køge, Denmark.
authors.forename: Signe
authors.initials: S
authors.lastname: Rosenlund
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Holsgaard-Larsen
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Overgaard
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Jensen
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait; D006615:Hip; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D015207:Osteoarthritis, Hip / Q000503:physiopathology*