Influence of Reach Direction During Performance of the Upper Quarter Y-Balance Test in Collegiate Softball Players

Softball is a sport of repetitive overhand throwing motions. As in most overhead throwing sports, the supporting structures around the shoulder experience high forces that cause microtrauma to the ligaments and muscles which can eventually lead to tendinitis, impingement, lesions, and instability.1 PURPOSE:The purpose of this study was to determine if there is a difference in strength and stability between throwing and non-throwing arms for collegiate softball players. Also, to determine if the sequence of reaches in the upper quarter Y-balance test (YBT-UQ) influences performance. METHODS: Twenty-two collegiate softball players (14 varsity, 8 club; 19.95 ± 1.52 yo) were recruited. IRB approved the study and participants granted informed consent. On the first day each subject was assigned one of two reach sequences either: 1) medial, 2) superolateral, 3)inferolateral (MSI) or 1)inferolateral, 2) superolateral, 3)medial (ISM). When participants returned for the second day of testing, they performed the opposite reach sequence. Paired sample t-tests with a significance cut-off point at pRESULTS: There were significant differences found between the right and left arms for MSI inferolateral reach (p=0.038) and MSI composite score (p=0.017). Significant differences were also found between ISM and MSI for medial reach (p=0.006), inferolateral reach (p=0.024), and composite score (p=9.2E-5) for the left arm. No significant differences found in any of the comparisons of ISM vs MSI for the right arm or in left vs right arm for ISM sequence. CONCLUSION:It is possible that the sequence of reaches can impact the scores for this assessment and may lead to incorrect interpretation of throwing vs non-throwing arms in the subject’s performance. The lack of difference in the throwing arm for ISM vs MSI indicates that it is less affected by the reach direction and change of sequence than the non-throwing arm