title: Hip joint motion and gluteal muscle activation differences between healthy controls and those with varying degrees of hip osteoarthritis during walking.
abstract: OBJECTIVE
  Compare gluteal muscle activation patterns and three-dimensional hip joint movements among those with severe hip osteoarthritis (OA), moderate OA and a healthy group during walking.
  
  
  METHODS
  20 individuals with severe OA, 20 with moderate OA and 20 healthy individuals were recruited. Three-dimensional hip motion and surface electromyograms from gluteus maximus and medius were collected during treadmill walking at a self-selected speed. Angular displacement characteristics were calculated for three-dimensional hip motions. Principal component analysis extracted amplitude and temporal features from electromyographic waveforms. Analysis of Variance models and student t-tests using Bonferroni corrections determined between group differences in these gait features (α = 0.05).
  
  
  CONCLUSIONS
  Sagittal plane hip range of motion was significantly reduced with increasing severity of OA (p < 0.05) where as frontal and transverse plane range of motion was reduced in the severe OA group only (p < 0.05). Activation patterns of gluteus medius and maximus did not differ between the healthy group and those with moderate hip OA (p > 0.05). Individuals with severe OA walking with more prolonged gluteus maximus activation and prolonged and less dynamic gluteus medius activation compared to the other two groups (p < 0.05). This study highlights the changing function of the hip joint during walking with increasing hip OA severity.
authors.affiliation: School of Physiotherapy, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada; School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada; School of Biomedical Engineering, Faculty of Engineering, Dalhousie University, Halifax, NS, Canada. Electronic address: djr@dal.ca.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Rutherford
authors.affiliation: School of Physiotherapy, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada; School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada. Electronic address: jmoreside@dal.ca.
authors.forename: Janice
authors.initials: J
authors.lastname: Moreside
authors.affiliation: School of Physiotherapy, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada; School of Health and Human Performance, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada; Department of Surgery, Division of Orthopaedics, Dalhousie University, Halifax, NS, Canada. Electronic address: iw@drivanwong.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Wong
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006621:Hip Joint / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D015207:Osteoarthritis, Hip / Q000503:physiopathology*; D016059:Range of Motion, Articular; D016138:Walking
keywords: Electromyography; Gait analysis; Gluteus maximus; Gluteus medius; Hip osteoarthritis; Principal component analysis; Range of motion