Assessment of Inspiratory Muscle Function and Glenohumeral Motion in the Throwing Arm of Division I Collegiate Baseball Players

This study investigated the relationships between inspiratory performance (IP) and glenohumeral rotation in Division 1 Collegiate baseball players (D1CBP). Thirty D1CBP were recruited. The Test of Incremental Respiratory Endurance (TIRE) provides maximal inspiratory pressure (MIP), sustained maximal inspiratory pressure (SMIP), and inspiratory duration (ID). Right and left glenohumeral internal and external rotation (RGHIR, RGHER, LGHIR, and LGHER, respectively) were measured with the shoulder in 90 degrees(d) of abduction. Significant differences between position groups were observed. IP of the entire group was significantly correlated to height, weight, and negatively correlated to right total rotational motion (RTRM) (r = −0.41; p < 0.05). The IP of all pitchers was significantly negatively correlated to both RTRM and LTRM (r = −0.56 to −0.61; p < 0.05). IP of right-handed pitchers was significantly correlated negatively to RGHER (r = −0.83 to −0.93; p < 0.05). IP of left-handed pitchers was significantly correlated negatively to LGHER (r = −0.82; p = 0.04). GH motions are significantly related to the IP of D1CBP. This association may be explained by the involvement of overstretched internal rotators, which act as accessory inspiratory muscles.