Glenohumeral range of motion deficits and posterior shoulder tightness in throwers with pathologic internal impingement.
BACKGROUND
Alterations in glenohumeral range of motion, including increased posterior shoulder tightness and glenohumeral internal rotation deficit that exceeds the accompanying external rotation gain, are suggested contributors to throwing-related shoulder injuries such as pathologic internal impingement. Yet these contributors have not been identified in throwers with internal impingement.


OBJECTIVE
Throwers with pathologic internal impingement will exhibit significantly increased posterior shoulder tightness and glenohumeral internal rotation deficit without significantly increased external rotation gain.


METHODS
Case control study; Level of evidence, 3.


METHODS
Eleven throwing athletes with pathologic internal impingement diagnosed using both clinical examination and a magnetic resonance arthrogram were demographically matched with 11 control throwers who had no history of upper extremity injury. Passive glenohumeral internal and external rotation were measured bilaterally with standard goniometry at 90 degrees of humeral abduction and elbow flexion. Bilateral differences in glenohumeral range of motion were used to calculate glenohumeral internal rotation deficit and external rotation gain. Posterior shoulder tightness was quantified as the bilateral difference in passive shoulder horizontal adduction with the scapula retracted and the shoulder at 90 degrees of elevation. Comparisons were made between groups with dependent t tests (P < .05).


RESULTS
The throwing athletes with internal impingement demonstrated significantly greater glenohumeral internal rotation deficit (P = .03) and posterior shoulder tightness (P = .03) compared with the control subjects. No significant differences were observed in external rotation gain between groups (P = .16).


CONCLUSIONS
These findings could indicate that a tightening of the posterior elements of the shoulder (capsule, rotator cuff) may contribute to impingement. The results suggest that management should include stretching to restore flexibility to the posterior shoulder.
Myers
Joseph B
JB
ATC, Neuromuscular Research Laboratory, UPMC Center for Sports Medicine, 3200 South Water Street, Pittsburgh, PA 15203, USA. myersjb@upmc.edu
Laudner
Kevin G
KG
Pasquale
Maria R
MR
Bradley
James P
JP
Lephart
Scott M
SM
D000328:Adult; D001484:Baseball; D016022:Case-Control Studies; D006801:Humans; D006811:Humerus / Q000503:physiopathology*; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D019534:Shoulder Impingement Syndrome / Q000503:physiopathology*; D012785:Shoulder Joint; D014481:United States