title: An acute throwing episode decreases shoulder internal rotation.
abstract: BACKGROUND
  Glenohumeral internal rotation (GIR) and total arc of motion (TAM) decrease, whereas external rotation (GER) may increase in throwing. Although decreased GIR has been documented after throwing, its time course for recovery and the effect of pitching role have not.
  
  
  OBJECTIVE
  We therefore asked (1) how much rotational change occurs after a single throwing episode; (2) do these changes return to baseline by the next throwing episode; and (3) does pitching role affect the amount of change that occurs?
  
  
  METHODS
  Forty-five pitchers, starters and relievers, were examined. GIR and GER measurements were taken at five time points (TP): before throwing (TP1); immediately after throwing (TP2); and 24 (TP3), 48 (TP4), and 72 (TP5) hours later. TAM was calculated as the combination of GIR and GER.
  
  
  RESULTS
  GIR decreased from TP1 to TP5 and did not return to baseline. GER changed very little and TAM decreased at TP5. Relievers had greater GIR, GER, and TAM across all time points, but the amount of change over all time points was not different between groups.
  
  
  CONCLUSIONS
  GIR was most affected over one 4-day throwing cycle after an acute throwing episode and was less than baseline 72 hours later. Pitching role did not affect the short-term changes.
  
  
  CONCLUSIONS
  GIR changes should be expected after an acute throwing episode and conditioning and recovery programs should be used to modify the changes. Because GIR is dynamic, studies on GIR should specifically state when during the pitching cycle the measurement was obtained.
authors.affiliation: Shoulder Center of Kentucky, 700 Bob-O-Link Drive, Lexington, KY 40504, USA. wkibler@aol.com
authors.forename: W Ben
authors.initials: WB
authors.lastname: Kibler
authors.forename: Aaron
authors.initials: A
authors.lastname: Sciascia
authors.forename: Stephanie
authors.initials: S
authors.lastname: Moore
mesh_terms: D000328:Adult; D001484:Baseball / Q000502:physiology*; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular; D012540:Scapula / Q000502:physiology; D012785:Shoulder Joint / Q000502:physiology*; D055815:Young Adult