title: Hip range of motion and association with injury in female professional tennis players.
abstract: BACKGROUND
  Adequate hip range of motion is required for the transfer of energy from the lower to the upper extremity along the kinetic chain. Repetitive rotational stresses in the lower extremities during tennis may lead to sport-specific range of motion adaptations, which may increase the risk of injury to other joints along the kinetic chain.
  
  
  OBJECTIVE
  To assess whether such range of motion adaptations occur in the hip, and if so, to identify whether they are associated with injury.
  
  
  METHODS
  Cross-sectional study; Level of evidence, 3.
  
  
  METHODS
  A total of 125 female professional tennis players, the majority of whom were ranked in the top 200 World Tennis Association singles rankings, underwent a comprehensive preparticipation physical health status examination. Hip range of motion was assessed using a digital inclinometer and side-to-side differences in rotational parameters calculated, and associations with previous injuries were identified.
  
  
  RESULTS
  A history of an abdominal strain was reported by 10% of players, and there was an association between abdominal strains and the presence of hip flexion contractures (odds ratio, 6.1; P = .006). Hip flexion contractures were bilateral in 85% of those found, affected only the nondominant side in 9%, and affected only the dominant side in 6%. We were unable to identify any specific side-to-side rotational adaptations in the dominant or nondominant hips, and no association between loss of hip range of motion and shoulder, lower back, hip, knee, or ankle injuries was found.
  
  
  CONCLUSIONS
  We report an association in female professional tennis players between abdominal strains and flexion contractures of the hip with iliopsoas tightness. We did not find evidence of specific hip adaptations in rotational range of motion. If hip flexion contractures are found on clinical examination, a stretching program may be indicated. Further studies are required to assess whether such a program can reduce the risk of abdominal injury.
authors.affiliation: Department of Orthopaedic Surgery, North Shore Hospital, University of Auckland, Auckland, New Zealand.
authors.forename: Simon W
authors.initials: SW
authors.lastname: Young
authors.affiliation: Sport Sciences and Medicine, Women's Tennis Association Tour, St Petersburg, Florida, USA.
authors.forename: Jodie
authors.initials: J
authors.lastname: Dakic
authors.affiliation: Sport Sciences and Medicine, Women's Tennis Association Tour, St Petersburg, Florida, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Stroia
authors.affiliation: Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Nguyen
authors.affiliation: Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Alex H S
authors.initials: AH
authors.lastname: Harris
authors.affiliation: Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California, USA msafran@stanford.edu.
authors.forename: Marc R
authors.initials: MR
authors.lastname: Safran
mesh_terms: D000009:Abdominal Muscles / Q000293:injuries; D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D004735:Energy Transfer / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006616:Hip Contracture / Q000209:etiology*; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D016059:Range of Motion, Articular; D012399:Rotation / Q000009:adverse effects; D013180:Sprains and Strains / Q000209:etiology*; D013715:Tennis / Q000293:injuries*; D055815:Young Adult
keywords: abdominal strains; hip clinical examination; hip range of motion; tennis players