Trunk-rotation flexibility in collegiate softball players with or without a history of shoulder or elbow injury.
BACKGROUND
Throwing is a whole-body motion that requires the transfer of momentum from the lower extremity to the upper extremity via the trunk. No research to date examines the association between a history of shoulder or elbow injury and trunk flexibility in overhead athletes.


OBJECTIVE
To determine if injury history and trunk-rotation flexibility are associated and to compare trunk-rotation flexibility measured using 3 clinical tests: half-kneeling rotation test with the bar in the back, half-kneeling rotation test with the bar in the front, and seated rotation test in softball position players with or without a history of shoulder or elbow injury.


METHODS
Cross-sectional design.


METHODS
University softball facilities.


METHODS
Sixty-five female National Collegiate Athletic Association Division I softball position players.


METHODS
Trunk-rotation flexibility was measured with 3 clinical tests. Recent injury history was obtained using a questionnaire and verified by the certified athletic trainer.


METHODS
Binomial regression models were used to determine if injury history was associated with flexibility categories (high, normal, or limited tertiles) for each of the 6 (3 tests × 2 directions) trunk-rotation flexibility measures. Trunk-rotation flexibility measures from 3 clinical tests were compared between participants with and without a history of shoulder or elbow injury using analysis-of-variance models.


RESULTS
When measured using the half-kneeling rotation test with the bar in the back and the seated rotation test, injury history and forward trunk-rotation flexibility were associated. However, no mean group differences were seen in trunk-rotation flexibility between participants with and without a history of shoulder or elbow injury.


CONCLUSIONS
Limited forward trunk-rotation flexibility may be a risk factor for shoulder or elbow injuries. However, further study is needed to confirm the study finding.
Athletics Department, Duke University, Durham, NC, USA.
Veronica J
VJ
Aragon
Sakiko
S
Oyama
Scott M
SM
Oliaro
Darin A
DA
Padua
Joseph B
JB
Myers
D056352:Athletes; D001484:Baseball; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D009068:Movement; D018583:Pliability; D016059:Range of Motion, Articular / Q000502:physiology*; D012399:Rotation; D000070599:Shoulder Injuries; D011795:Surveys and Questionnaires; D060726:Torso / Q000502:physiology*; D034941:Upper Extremity / Q000502:physiology*; D000092464:Elbow Injuries