title: High Incidence of Infraspinatus Muscle Atrophy in Elite Professional Female Tennis Players.
abstract: BACKGROUND
  Isolated infraspinatus muscle atrophy is common in overhead athletes, who place significant and repetitive stresses across their dominant shoulders. Studies on volleyball and baseball players report infraspinatus atrophy in 4% to 34% of players; however, the prevalence of infraspinatus atrophy in professional tennis players has not been reported.
  
  
  OBJECTIVE
  To investigate the incidence of isolated infraspinatus atrophy in professional tennis players and to identify any correlations with other physical examination findings, ranking performance, and concurrent shoulder injuries.
  
  
  METHODS
  Cross-sectional study; Level of evidence, 3.
  
  
  METHODS
  A total of 125 professional female tennis players underwent a comprehensive preparticipation physical health status examination. Two orthopaedic surgeons examined the shoulders of all players and obtained digital goniometric measurements of range of motion (ROM). Infraspinatus atrophy was defined as loss of soft tissue bulk in the infraspinatus scapula fossa (and increased prominence of dorsal scapular bony anatomy) of the dominant shoulder with clear asymmetry when compared with the contralateral side. Correlations were examined between infraspinatus atrophy and concurrent shoulder disorders, clinical examination findings, ROM, glenohumeral internal rotation deficit, singles tennis ranking, and age.
  
  
  RESULTS
  There were 65 players (52%) with evidence of infraspinatus atrophy in their dominant shoulders. No wasting was noted in the nondominant shoulder of any player. No statistically significant differences were seen in mean age, left- or right-hand dominance, height, weight, or body mass index for players with or without atrophy. Of the 77 players ranked in the top 100, 58% had clinical infraspinatus atrophy, compared with 40% of players ranked outside the top 100. No associations were found with static physical examination findings (scapular dyskinesis, ROM glenohumeral internal rotation deficit, postural abnormalities), concurrent shoulder disorders, or compromised performance when measured by singles ranking.
  
  
  CONCLUSIONS
  This study reports a high level of clinical infraspinatus atrophy in the dominant shoulder of elite female tennis players. Infraspinatus atrophy was associated with a higher performance ranking, and no functional deficits or associations with concurrent shoulder disorders were found. Team physicians can be reassured that infraspinatus atrophy is a common finding in high-performing tennis players and, if asymptomatic, does not appear to significantly compromise performance.
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: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D009133:Muscular Atrophy / Q000453:epidemiology* / Q000503:physiopathology; D010808:Physical Examination; D016059:Range of Motion, Articular / Q000502:physiology; D012399:Rotation; D017006:Rotator Cuff / Q000503:physiopathology; D012782:Shoulder / Q000503:physiopathology; D000070599:Shoulder Injuries; D013715:Tennis / Q000293:injuries*; D055815:Young Adult
keywords: infraspinatus atrophy; shoulder clinical examination; shoulder muscle atrophy; tennis players