Inter-limb differences in upper quarter mobility/stability are not associated with performance in competitive swimmers

The Y Balance Test-Upper Quarter (YBT-UQ) is a cost-effective, well-established, closed kinetic chain test to assess inter-limb asymmetries in the upper quarter that could negatively affect swimming performance. Thus, the aim of the present study was to determine YBT-UQ performances and inter-limb differences as well as its association with swimming performance in athletes with diverging levels of expertise. Forty female and male competitive swimmers (age range: 10-22 years) with different expertise levels (A-squad: = 9, B-squad: = 12, C-squad: = 19) were tested (reach distances for the YBT-UQ) and swimming performance was calculated using the ratio of individual to world best time. YBT-UQ performances (i.e., inferolateral reach direction for the dominant arm: = .027, = .12 and the non-dominant arm: = .031, = .17) but not YBT-UQ inter-limb differences significantly differed between groups and were largest in swimmers with the lowest expertise level (i.e., C-squad). Further, YBT-UQ performances (i.e., inferolateral reach direction [ = -.68 to -.70, both