Validity and reliability of upper extremity star excursion balance test in adolescent swimmers

Upper limb balance is one of the important physical fitness parameters for all populations, especially overhead athletes like swimmers. Upper extremity star excursion balance test (UESEBT) is a comprehensive dynamic balance assessment, this study aims to explore the reliability and validity of UESEBT among adolescent swimmers.

This cross-sectional study recruited 70 adolescent swimmers. All participants were required to complete UESEBT, upper quarter Y-balance test (UQYBT), maximal isometric strength (MIS) tests in upper limb, closed kinetic chain upper extremity stability test (CKCUEST), trunk flexor endurance test (TFET) and lateral trunk endurance test (LTET). The intra- and inter-operator reliability and the correlation of UESEBT with other physical performances were conducted.

For reliability, the intra- and inter-operator reliability of all directions and composite score were high-to-excellent (ICC = 0.706-1.000) among all participants. For validity, the UESEBT has a moderate-to-strong correlation with UQYBT (r = 0.42-0.72, p < 0.001), and a weak-to moderate one with CKCUEST (r = 0.25-0.42, p < 0.05). Furthermore, the UESEBT performance showed weak-to-moderate correlations with MIS (r = 0.24-0.44, p < 0.05). UESEBT was correlated to LTET (r = 0.24-0.33, p < 0.05) whereas no relationship was found with TFET.

UESEBT was a reliable and valid tool to screen upper extremity dynamic balance among adolescent swimmers. UESEBT provides more detailed information in eight directions to assess the upper limb sport performance. Further study should explore the prediction ability of UESEBT for injury.