title: Associations between changes in knee pain location and clinical symptoms in people with medial knee osteoarthritis using footwear for self-management: an exploratory study.
abstract: To examine whether change in pain location is associated with clinically-relevant improvements in walking pain severity and physical dysfunction in people with medial tibiofemoral osteoarthritis (OA) using footwear for self-management.
  
  
  
  We analysed a sub-set of 91 participants pooled from both arms of a 6-month randomised controlled trial of footwear for knee OA. The Photographic Knee Pain Map was self-administered to generate changes in the number of painful zones ('unchanged', 'increased', 'decreased') and anatomical patterns of pain ('unchanged', 'no longer diffuse', 'becoming diffuse', 'other pattern changes'). Improvement in symptoms was determined using the minimum clinically important differences (MCIDs) in pain severity on a numeric rating scale, and function with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Fisher's exact tests examined differences in symptom improvement across categories of change and odds ratios (ORs, 95% CI) were calculated (adjusted for treatment allocation).
  
  
  
  Seventy-four percent (n = 67) of participants reported a change in pain location, and 46-50% (n = 42-45) reported clinically-relevant improvements in pain and function respectively. Fewer participants 'becoming diffuse' reported improved pain (n = 0, 0%) when compared to the other pattern change categories (P = 0.012). Participants with 'no longer diffuse' (OR (95% CI) = 0.3 (0.1-0.9) or 'becoming diffuse' (OR (95% CI) = 0.0 (0.0-0.4) pain patterns had significantly lower odds of improved function than those with 'other pattern changes'.
  
  
  
  Participants either developing into, or changing from, diffuse pain patterns were less likely to experience improvement in pain and/or function when self-managing with footwear.
authors.affiliation: Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, University of Melbourne, Victoria, Australia. Electronic address: ansvg@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Van Ginckel
authors.affiliation: Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, University of Melbourne, Victoria, Australia. Electronic address: k.bennell@unimelb.edu.au.
authors.forename: K L
authors.initials: KL
authors.lastname: Bennell
authors.affiliation: Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, University of Melbourne, Victoria, Australia. Electronic address: penelope.campbell@unimelb.edu.au.
authors.forename: P K
authors.initials: PK
authors.lastname: Campbell
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Victoria, Australia. Electronic address: jessica.kasza@monash.edu.
authors.forename: J
authors.initials: J
authors.lastname: Kasza
authors.affiliation: Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, University of Melbourne, Victoria, Australia. Electronic address: timw@unimelb.edu.au.
authors.forename: T V
authors.initials: TV
authors.lastname: Wrigley
authors.affiliation: Department of Rheumatology, Royal North Shore Hospital, New South Wales, Australia; Institute of Bone and Joint Research, Kolling Institute of Medical Research, The University of Sydney, New South Wales, Australia. Electronic address: david.hunter@sydney.edu.au.
authors.forename: D J
authors.initials: DJ
authors.lastname: Hunter
authors.affiliation: Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, School of Health Sciences, University of Melbourne, Victoria, Australia. Electronic address: ranash@unimelb.edu.au.
authors.forename: R S
authors.initials: RS
authors.lastname: Hinman
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000628:therapy*; D010147:Pain Measurement / Q000379:methods; D000073278:Self-Management / Q000379:methods*; D012775:Shoes; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology
keywords: Clinically-relevant improvement; Function; Pain; Pain location change; Pain map