Exploration of the y-balance test for assessment of upper quarter closed kinetic chain performance.

BACKGROUND: Although upper extremity (UE) closed kinetic chain (CKC) exercises have become commonplace in most rehabilitation programs, a clinically meaningful UE CKC functional test of unilateral ability has continued to be elusive.
OBJECTIVES: To examine reliability of the Upper Quarter Y-Balance Test (UQYBT), evaluate the effects of arm dominance on UQYBT performance, and to determine how the UQYBT is related to specific components of the test (trunk rotation, core stability and UE function and performance) in a college-aged population.
METHODS: A sample of healthy college students performed the UQYBT and a series of 6 additional dynamic tests designed to assess trunk rotation, core stability, and UE performance. The relationship of these tests compared to the UQYBT was assessed. The effect of upper limb dominance for the UQYBT was also explored. Finally, test re-test reliability was established for the UQYBT.
RESULTS: Thirty subjects (24 males, 6 females, mean ages 19.5 6 1.2 and 18.8 6 0.8 years) were assessed during the study. The test re-test reliability was excellent for UQYBT measurements (intraclass correlation coefficient > 0.9). A significant (p <0.05) fair to moderate association was observed between the UQYBT and several core stability and UE functional tests. There was no significant difference in UQYBT performance between dominant and non-dominant limbs. DISCUSSION: The UQYBT is a reliable UE CKC test that can be used to assess unilateral UE function in a closed chain manner. The UQYBT appears to be most related to dynamic tests involving core stability and UE performance. Similarity on the UQYBT between dominant and non-dominant limbs indicates that performance on this test using a non-injured UE may serve as a reasonable measure for "normal" when testing an injured UE. Future research is needed to determine the clinical applicability of the UQYBT. LEVEL OF EVIDENCE: 2b.