title: The impact of symptomatic knee osteoarthritis on overall gait pattern deviations and its association with performance-based measures and patient-reported outcomes.
abstract: BACKGROUND
  Limited knowledge exists regarding the impact of symptomatic knee osteoarthritis (OA) on the overall gait pattern; and whether gait deviations are associated with performance-based measures (PBMs) and patient-reported outcomes (PROs). This cross-sectional study evaluated overall gait patterns in patients with knee OA using the Gait Deviation Index for kinematics (GDI) and kinetics (GDI-kinetic), and explored associations between gait deviations, PBMs, and PROs.
  
  
  METHODS
  Forty patients with knee OA and 25 age and gender-matched controls underwent three-dimensional gait analysis. Participants performed the Timed Up and Go (TUG), Five Times Sit-to-Stand (5STS), and Single Limb Mini Squat (SLMS) tests and completed a disease-specific PRO. Associations between gait deviations, PBMs, and PROs were assessed by Pearson's correlation and multiple linear regression.
  
  
  RESULTS
  Patients with OA demonstrated significantly lower GDI and GDI-kinetic scores of the OA and contralateral limbs compared to controls; with GDI-kinetic scores on the contralateral limb more impacted than the OA limb. On the contralateral limb, GDI-kinetic score significantly correlated with TUG (r=-0.42) and 5STS (r=-0.33), while on the OA limb with TUG (r=-0.68), 5STS (r=-0.38), SLMS (r=-0.38), activities of daily living (r=0.35) and Knee-related Quality of Life (r=0.35). No significant associations existed between kinematic GDI scores, PBMs and PROs.
  
  
  CONCLUSIONS
  The overall gait pattern, as represented by GDI and GDI-kinetic scores, in patients with symptomatic knee OA is affected both on the painful OA limb and the contralateral limb. The GDI and GDI-kinetic scores provide different information regarding function that is not revealed by PBMs or PROs.
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet, MotorikLab, Q2:07, Karolinska University Hospital, 171 76 Stockholm, Sweden. Electronic address: josefine.naili@ki.se.
authors.forename: Josefine E
authors.initials: JE
authors.lastname: Naili
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet, MotorikLab, Q2:07, Karolinska University Hospital, 171 76 Stockholm, Sweden.
authors.forename: Anna-Clara
authors.initials: AC
authors.lastname: Esbjörnsson
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet, MotorikLab, Q2:07, Karolinska University Hospital, 171 76 Stockholm, Sweden; Department of Physical Therapy, Movement & Rehabilitation Sciences, Bouve College of Health Sciences, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA; Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Maura D
authors.initials: MD
authors.lastname: Iversen
authors.affiliation: Gillette Children's Specialty Healthcare, 200 University Avenue East, St Paul, MN 55101, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA; Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Schwartz
authors.affiliation: Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Orthopedics, Karolinska University Hospital, 141 86 Stockholm, Sweden.
authors.forename: Margareta
authors.initials: M
authors.lastname: Hedström
authors.affiliation: Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Charlotte K
authors.initials: CK
authors.lastname: Häger
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet, MotorikLab, Q2:07, Karolinska University Hospital, 171 76 Stockholm, Sweden.
authors.forename: Eva W
authors.initials: EW
authors.lastname: Broström
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D000071066:Patient Reported Outcome Measures
keywords: Biomechanics; Function; Gait; Osteoarthritis; Outcome measures