Deficits in Glenohumeral Passive Range of Motion Increase Risk of Shoulder Injury in Professional Baseball Pitchers: A Prospective Study.
BACKGROUND
Shoulder injuries from repetitive baseball pitching continue to be a serious, common problem.


OBJECTIVE
To determine whether passive range of motion of the glenohumeral joint was predictive of shoulder injury or shoulder surgery in professional baseball pitchers.


METHODS
Cohort study; Level of evidence, 2.


METHODS
Passive range of motion of the glenohumeral joint was assessed with a bubble goniometer during spring training for all major and minor league pitchers of a single professional baseball organization over a period of 8 successive seasons (2005-2012). Investigators performed a total of 505 examinations on 296 professional pitchers. Glenohumeral external and internal rotation was assessed with the pitcher supine and the arm abducted to 90° in the scapular plane with the scapula stabilized anteriorly at the coracoid process. Total rotation was defined as the sum of internal and external glenohumeral rotation. Passive shoulder flexion was measured with the pitcher supine and the lateral border of the scapula manually stabilized. After examination, shoulder injuries and injury durations were recorded by each pitcher's respective baseball organization and reported to the league as an injury transaction as each player was placed on the disabled list.


RESULTS
Highly significant side-to-side differences were noted within subjects for each range of motion measurement. There were 75 shoulder injuries and 20 surgeries recorded among 51 pitchers, resulting in 5570 total days on the disabled list. Glenohumeral internal rotation deficit, total rotation deficit, and flexion deficit were not significantly related to shoulder injury or surgery. Pitchers with insufficient external rotation (<5° greater external rotation in the throwing shoulder) were 2.2 times more likely to be placed on the disabled list for a shoulder injury (P = .014; 95% CI, 1.2-4.1) and were 4.0 times more likely to require shoulder surgery (P = .009; 95% CI, 1.5-12.6).


CONCLUSIONS
Insufficient shoulder external rotation on the throwing side increased the likelihood of shoulder injury and shoulder surgery. Sports medicine clinicians should be aware of these findings and develop a preventive plan that addresses this study's findings to reduce pitchers' risk of shoulder injury and surgery.
Champion Sports Medicine, Birmingham, Alabama, USA American Sports Medicine Institute, Birmingham, Alabama, USA kwilkpt@hotmail.com.
Kevin E
KE
Wilk
Champion Physical Therapy & Performance, Waltham, Massachusetts, USA.
Leonard C
LC
Macrina
American Sports Medicine Institute, Birmingham, Alabama, USA.
Glenn S
GS
Fleisig
American Sports Medicine Institute, Birmingham, Alabama, USA.
Kyle T
KT
Aune
Tampa Bay Rays Baseball Organization, Tampa, Florida, USA.
Ron A
RA
Porterfield
Tampa Bay Rays Baseball Organization, Tampa, Florida, USA.
Paul
P
Harker
American Sports Medicine Institute, Birmingham, Alabama, USA.
Timothy J
TJ
Evans
American Sports Medicine Institute, Birmingham, Alabama, USA.
James R
JR
Andrews
D000328:Adult; D001265:Athletic Injuries / Q000503:physiopathology* / Q000601:surgery; D001484:Baseball / Q000293:injuries*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000503:physiopathology / Q000601:surgery
external rotation; glenohumeral internal rotation deficit; labral repair; rotator cuff repair; total rotational motion