EXPLORATION OF THE Y-BALANCE TEST FOR ASSESSMENT OF UPPER QUARTER CLOSED KINETIC CHAIN PERFORMANCE

Currently, there is very little evidence supporting clinically important UE functional testing for return to sport.  One that is used often is the UE Y-Balance Test.  In this study, the purpose was to determine reliability of the UQYBT in a college aged population.  Additionally, these authors sought to determine how the UQYBT related to specific components of the test, as well as evaluate how arm dominance effects performance on the UQYBT.  This study was an interesting read and gives us some additional support for this test.  While there are many limitations, it was a good starting point for future studies.  

AUTHORS:  
- Richard B Westrick, PT, DPT, DSc, OCS, SCS
- Joseph M Miller, PT, DPT, DSc, OCS, SCS
- Scott D Carow, PT, DPT, DSc, OCS
- J. Parry Gerber, PT, PhD, SCS, ATC

Design:  30 healthy, college aged subjects from United States Military Academy at West Point.  
Exclusion Criteria:  UE or spine pain or injury within past 6 months, hx of shoulder surgery, or current illness or disease affecting performance.  

Testing:  

In this study the authors tested the UQYBT and 7 other tests (Closed Kinetic Chain UE Stability Test, Shoulder AROM & Isometric Strength Testing, Shoulder Mobility Reach Test, Trunk Rotation Test, Lateral Trunk Endurance Test, Trunk Extensor Endurance Test, and Trunk Flexor Endurance Test).  Each of these tests were given 2 mins rest in between and randomized for sequence.  

Findings:  

** The UQYBT test re-test reliability values were SIMILAR for both dominant and non-dominant.
** There was a significant relationship between UQYBT and core stability measures and UE CKC performance measures.
** There was NO statistically significant difference between dominant and non-dominant limbs on any of the measures, however performance in each direction was greater when non-dominant UE was stabilizing.
** NO statistical difference in gender (although 24 males to 6 females may be a limitation)

Limitations:  

- Small sample size
- Healthy population only
- A single tester collected all the data including reliability measures. So what do these results mean?  

WHAT SHOULD I TAKE AWAY FROM THIS? 

Well, you could potentially make the argument that since there was symmetry between limbs you could use the non-injured limb as a baseline when assessing the injured limb.  Additionally, we have some additional evidence to support that the UQYBT is reliable in assessing unilateral UE dynamic function in a CKC position.  It is also worth noting that the CKCUEST has been reported as reliable for UE performance, as this study reminds us of.  I think the important thing to remember is that like many studies, this was done with healthy population.  Also, this study was not focusing on any specific sport which I think would be a great study because I would imagine baseball players. for example, would potentially show differences in dominant vs non-dominant limbs for the UQYBT.  We just don't know.  However, creating reliable tests in different sports is important for us as clinicians so that we can make more relevant decisions in what criteria we use for return to sport in each UE injury.  

Please feel free to comment on what UE return to sport tests you use in the clinic or what tests you think may be relevant for each sport in UE injuries.  It would be interesting to generate discussion/debate on this topic.

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