title: Relationship between physical activity and hip pain in persons with and without cam or pincer morphology: a population-based case-control study.
abstract: The purpose of the study was to determine if physical activity (PA) is a risk factor for persistent or recurrent hip pain in young and middle-aged persons with and without radiographic findings of cam or pincer morphology (CPM).
  
  
  
  A population sample of persons aged 20-49 with (cases) and without (controls) hip pain in Metro Vancouver, Canada, was selected through random digit dialing (RDD). Self-reported PA was expressed as average energy expenditure (MET-hours) per year, over lifetime. CPM was defined as alpha angle >55°, lateral centre edge angle (LCE) >40°, or positive cross-over sign.
  
  
  
  Data were obtained for 500 subjects, 269 cases and 231 controls. Prevalence of radiographic CPM was 49% in the cases and 44% in the controls. In a logistic regression model adjusted for age, gender and CPM, total lifetime PA, including occupational, domestic and recreational activities, was significantly associated with hip pain (Odds ratio (OR) 1.30 per 1000 MET-hours, 95% CI 1.15-1.38). The effect of total PA was observed in those with CPM (1.44, 1.17-1.78) and without CPM (1.23, 1.04-1.45). For domestic activities, the association was seen only in those with CPM (significant interaction). When PA was categorized into quartiles, higher levels of PA were associated with a greater risk of pain.
  
  
  
  PA, as measured by average energy expenditure over lifetime is a risk factor for hip pain in young and middle-aged persons. For some activities, the risk is likely increased in persons with radiographic evidence of CPM.
authors.affiliation: School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada; Arthritis Research Canada, Richmond, BC, Canada. Electronic address: jkopec@arthritisresearch.ca.
authors.forename: J A
authors.initials: JA
authors.lastname: Kopec
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, BC, Canada; Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Cibere
authors.affiliation: Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada; Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: L C
authors.initials: LC
authors.lastname: Li
authors.affiliation: Department of Family Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Barber
authors.affiliation: Centre for Health Evaluation and Outcome Sciences, St. Paul's Hospital, Vancouver, BC, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Qian
authors.affiliation: School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Wong
authors.affiliation: Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Steininger
authors.affiliation: Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Prlic
authors.affiliation: York University, Toronto, ON, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Simatovic
authors.affiliation: Arthritis Centre and College of Medicine, University of Arizona, Tucson, AZ, USA.
authors.forename: C
authors.initials: C
authors.lastname: Ratzlaff
authors.affiliation: Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: E C
authors.initials: EC
authors.lastname: Sayre
authors.affiliation: Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Radiology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: B B
authors.initials: BB
authors.lastname: Forster
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, BC, Canada; Arthritis Research Canada, Richmond, BC, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: Esdaile
mesh_terms: D000328:Adult; D017677:Age Distribution; D001955:British Columbia / Q000453:epidemiology; D016022:Case-Control Studies; D059350:Chronic Pain / Q000453:epidemiology / Q000209:etiology / Q000473:pathology; D015444:Exercise / Q000502:physiology*; D005260:Female; D057925:Femoracetabular Impingement / Q000150:complications / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D012008:Recurrence; D012307:Risk Factors; D017678:Sex Distribution; D055815:Young Adult
keywords: Cam morphology; Case–control studies; Femoroacetabular impingement syndrome; Hip pain; Physical activity; Pincer morphology