Relation between glenohumeral internal rotation deficit and valgus laxity of the elbow in high school baseball pitchers.

Background: There are few literatures describing the association between glenohumeral internal rotation deficits (GIRD) and valgus laxity of the elbow on the throwing side of high school pitchers with and without a history of elbow symptom.

Methods: The passive range of motion of glenohumeral internal and external rotation on bilateral side shoulders was measured in 75 high-school baseball pitchers during the preseason. Using ultrasonography, the width of the ulnohumeral joint of the elbow was measured at 30° of flexion, both at rest and with valgus stress in the pitching side. Comparisons of glenohumeral internal rotation deficits and the difference between the width of ulnohumeral joint space with and without valgus stress on the throwing side were made between 75 high-school pitchers with and without a history of elbow symptom.

Results: Participants with a history of elbow symptom exhibited a greater difference between the width of ulnohumeral joint with and without valgus stress in the throwing side than participants with no history of elbow symptom (P<0.05). No difference in glenohumeral internal rotation deficits was found in participants with and without a history of elbow symptom. In all participants, significant association was found between glenohumeral internal rotation deficits on the pitching side and the difference from the width of the ulnohumeral joint with and without valgus stress (P=0.04, r=0.23).

Conclusions: Elbow valgus instability was associated with elbow joint pain in high-school pitchers. Although GIRD was not significantly different between the two groups, GIRD and elbow valgus instability might be related to the throwing side in high-school pitchers.