Normative data and inter-examiner reliability of the upper quarter Y-balance test

Abstract

Background/Aims Physical performance measures, such as the lower quarter Y-balance test, can be used to determine performance ability or functional limitations. The aim of this study was to establish a normative data set for the upper quarter Y-balance test and evaluate inter-rater reliability. Methods Healthy participants, with no current upper extremity complaint or balance issues, were recruited. Participants undertook the upper quarter Y-balance test by reaching in three directions: medial; superolateral; and inferolateral. Each participant completed three reaches on each side. The mean of the second and third reach distances was used for the analysis and reach distance was normalised to limb length. Results Mean participant age was 24.3 (± 5.6) years. Statistically significant differences between males and females were observed for all reach directions (both raw and normalised data), with large to very large effect sizes (P<0.001, effect size (r)=0.82–1.92). Results showed statistically significant differences between left- and right-hand dominance with left inferolateral reach (P=0.038, z=−2.076, r=0.21). Inter-rater reliability was excellent, with an intraclass correlation coefficient (3,1) of 0.98. Conclusions The results suggest that males have a statistically significantly larger reach in all directions and that participants reach significantly further when testing the dominant arm versus the non-dominant arm. The data presented here provide researchers with a substantive normative data set that will allow for comparison with symptomatic populations.