title: Which factors differentiate athletes with hip/groin pain from those without? A systematic review with meta-analysis.
abstract: BACKGROUND
  Hip and groin injuries are common in many sports. Understanding the factors differentiating athletes with hip/groin pain from those without these injuries could facilitate management and prevention.
  
  
  OBJECTIVE
  Conduct a systematic review and meta-analysis of the literature on factors differentiating athletes with and without hip/groin pain.
  
  
  METHODS
  The review was registered as PROSPERO CRD42014007416 and a comprehensive, systematic search was conducted in June 2014. Inclusion criteria were: cross-sectional, cohort or case-control study designs of n>10 that examined outcome measures differentiating athletes with and without hip/groin pain. Two authors independently screened search results, assessed study quality, and performed data extraction. Methodological heterogeneity was determined and data pooled for meta-analysis when appropriate. A best evidence synthesis was performed on the remaining outcome measures.
  
  
  RESULTS
  Of 2251 titles identified, 17 articles were included of which 10 were high quality. Sixty two different outcome measures were examined, 8 underwent meta-analysis. Pooled data showed strong evidence that athletes with hip/groin pain demonstrated: pain and lower strength on the adductor squeeze test, reduced range of motion in hip internal rotation and bent knee fall out; however, hip external rotation range was equivalent to controls. Strong evidence was found that lower patient-reported outcome (PRO) scores, altered trunk muscle function, and moderate evidence of bone oedema and secondary cleft sign were associated with hip/groin pain.
  
  
  CONCLUSIONS
  PROs, pain and reduced strength on the adductor squeeze test, reduced range of motion in internal rotation and bent knee fall out are the outcome measures that best differentiate athletes with hip/groin pain from those without this pain.
authors.affiliation: Rehabilitation Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia.
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Mosler
authors.affiliation: Department of Orthopaedics, Erasmus University Medical Centre, Rotterdam, the Netherlands.
authors.forename: Rintje
authors.initials: R
authors.lastname: Agricola
authors.affiliation: Sports Groin Pain Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
authors.forename: Adam
authors.initials: A
authors.lastname: Weir
authors.affiliation: Sports Groin Pain Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Arthroscopic Center Amager, SORC-C, Copenhagen University Hospital, Amager-Hvidovre, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Hölmich
authors.affiliation: School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia School of Allied Health, La Trobe University, Victoria, Australia.
authors.forename: Kay M
authors.initials: KM
authors.lastname: Crossley
mesh_terms: D015746:Abdominal Pain / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D018771:Arthralgia / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D006119:Groin; D006621:Hip Joint; D006801:Humans; D007719:Knee Joint; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D010147:Pain Measurement; D063868:Patient Outcome Assessment; D016059:Range of Motion, Articular / Q000502:physiology; D013177:Sports / Q000502:physiology*; D060726:Torso
keywords: Athlete; Groin; Hip; Injuries; Sports