title: Humeral retrotorsion in collegiate baseball pitchers with throwing-related upper extremity injury history.
abstract: BACKGROUND
  Collegiate baseball pitchers, as well as position players, exhibit increased humeral retrotorsion compared with individuals with no history of overhead sport participation. Whether the humeral retrotorsion plays a role in the development of throwing-related injuries that are prevalent in collegiate baseball pitchers is unknown.
  
  
  OBJECTIVE
  Humeral retrotorsion will be significantly different in collegiate pitchers with throwing-related shoulder or elbow injury history compared with pitchers with no injury history. Humeral retrotorsion can also discriminate participants with and without shoulder or elbow injury.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Comparisons of ultrasonographically-obtained humeral retrotorsion were made between 40 collegiate pitchers with and without history of throwing-related shoulder or elbow injury. The ability of humeral retrotorsion to discriminate injury history was determined from the receiver operating characteristic area under the curve.
  
  
  RESULTS
  Participants with an elbow injury history demonstrated a greater humeral retrotorsion limb difference (mean difference = 7.2°, P = 0.027) than participants with no history of upper extremity injury. Participants with shoulder injury history showed no differences in humeral torsion compared with participants with no history of injury. Humeral retrotorsion limb difference exhibited a fair ability (receiver operating characteristic area under the curve = 0.74) to discriminate elbow injury history.
  
  
  CONCLUSIONS
  Collegiate pitchers with a history of elbow injury exhibited a greater limb difference in humeral retrotorsion compared with pitchers with no history of injury. No differences in humeral retrotorsion variables were present in participants with and without shoulder injury history.
  
  
  CONCLUSIONS
  Baseball players with a history of elbow injury demonstrated increased humeral retrotorsion, suggesting that the amount of retrotorsion and the development of elbow injury may be associated.
authors.affiliation: Sports Medicine Laboratory and Neuromuscular Research Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina ; Department of Orthopaedics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Myers
authors.forename: Sakiko
authors.initials: S
authors.lastname: Oyama
authors.forename: Terri Jo
authors.initials: TJ
authors.lastname: Rucinski
authors.forename: R Alexander
authors.initials: RA
authors.lastname: Creighton