The Effectiveness of the Y Balance Test Compared to the Star Excursion Balance Test: A Critically Appraised Topic

Heidi Krueger, Nikki German, PhD, ATC

North Dakota State University

Department of Health, Nutrition and Exercise Sciences, Fargo ND, USA

Abstract

Clinical Question

Characteristics of Included Studies

Two studies in this CAT evaluated the differences between the Star Excursion Balance Test and the Y Balance Test on physically active males and females. Both studies found that the anterior reach direction had a significant difference between the two tests. There was no significant difference between the other two reach directions. Therefore, the two tests cannot be used interchangeably. The other two studies evaluated the reliability for the two balance tests. The Star Excursion Balance Test was shown to have good reliability as long as the tester has been trained and practiced administering the test. The Y Balance Test was shown to have good to excellent reliability due standardized protocol and testing instrument. However, all four studies have limited quality, and as such, conclusions should be interpreted with caution. Each study suggested that both the Star Excursion Balance Test and the Y Balance Test were effective and reliable. There are positives and negatives for both balance tests, but evidence has found that the two tests cannot be used interchangeably. Choosing one test is the best way to compare dynamic neuromuscular control deficiencies for prevention, or improvements after injury. The Star Excursion Balance Test has eight original reach directions, a varying start position, and varying protocols.1,3,4 The Y Balance Test has three reach directions, a clear starting position, a clear, standardized protocol; and a commercially crafted testing kit to improve reliability and repeatability.1,2,4 Athletic Trainers and other health care providers value quality information in a short amount of time. Y Balance can test dynamic neuromuscular control and unilateral balance for preventing injury and also returning patients to activity quickly and effectively. The conclusion from the four studies in this CAT is that the Y Balance Test was designed to improve the limitations of the Star Excursion Balance Test. It is noteworthy that three of the four studies were not conducted within the United States; therefore, it may limit the ability to generalize the outcomes and recommendations. The four studies contained 20, 29, 15, and 15 participants making it difficult to generalize with a limited number of studies conducted. All of the studies were conducted using university participants suggesting that they were physically active. However, it is unclear how the results translate to other age ranges regardless of physical activity level. Future research should include determining which balance test is more clinically appropriate when looking at the entire scope of determining injury risk, return to play, and possibly concussion protocol. Longitudinal studies would provide data on the usefulness of neuromuscular control screening before participation to address the issues to decrease injuries and return to physical activity decisions making. In addition, studies that include a greater sample of sports and age range would increase external validity and overall ability to generalize the outcomes. Additionally, this CAT should be reviewed in two years to determine whether additional best evidence has been published that may change the clinical bottom line for this specific clinical question.

Clinical Scenario: Dynamic neuromuscular control and unilateral balance are important requirements for sports and essential daily living activities as we age. Evaluating these components has been a way many clinicians are able to identify individuals at a greater risk for injury.1- 4 The Star Excursion Balance Test incorporates eight reach directions while standing on each foot separately. The intra rater reliability of the Star Excursion Balance Test is found to be moderate to good, while the inter rate reliability is found to be poor to good.3 The Y Balance Test was developed to improve the Star Excursion Balance Test by defining questionable variables of the Star Excursion Balance Test. More evidence is needed to ensure that the new instrument assesses dynamic neuromuscular control and unilateral balance is effective and useful in the clinical setting. Summary of Search, “Best Evidence” Appraised and Key Findings: The literature was searched for studies of level 3 evidence or higher that investigated the effectiveness of the Y Balance Test compared to the Star Excursion Balance Test in physically active males and females. The literature search resulted in two articles comparing the tests and two articles concerning test reliability. All four quality articles were included.

Inclusion • Studies that compared Y Balance Test and Star Excursion Test • Limited to English language • Limited to humans • Limited to the last ten years (2006 – 2016) • Level 3 evidence or higher Exclusion • If not Y Balance Test • If not Star Excursion Balance Test • Non-physically-active subjects

Implications for Practice, Education and Future Research

1. Coughlan GF, Fullam K, Delahunt E, Gissane C, Caulfield BM. A comparison between performance on selected directions of the star excursion balance test and the Y balance test. J Athl Train. 2012;47(4):366-71.

2. Gribble PA, Kelly SE, Refshauge KM, Hiller CE. Interrater reliability of the star excursion balance test. J Athl Train. 2013;48(5):621-6.

3. Plisky PJ, Gorman PP, Butler RJ, Kiesel KB, Underwood FB, Elkins B. The reliability of an instrumented device for measuring components of the star excursion balance test. N Am J Sports Phys Ther. 2009;4(2):92-9.

4. Fullam K, Caulfield B, Coughlan GF, Delahunt E. Kinematic analysis of selected reach directions of the Star Excursion Balance Test compared with the Y-Balance Test. J Sport Rehabil. 2014;23(1):27-35.

References

Summary of Search, “Best Evidence” appraised, and Key Findings Summary of Search, “Best Evidence” appraised, and Key Findings

Clinical Bottom Line

Is the Star Excursion Balance Testing data interchangeable with the Y Balance Testing data in physically active males and females?

There is moderate evidence to support the use of short-term immobilization with early motion to increase the healing process and reduce the recovery time following a surgically repaired Achilles tendon rupture.

Inclusion and Exclusion Criteria

Terms Used to Guide Search Strategy •  Patient/Client Group: Active females OR males •  Intervention (or Assessment): Y Balance Test •  Comparison: Star Excursion Balance Test •  Outcome(s): Interchangeability between test data (reach distances for all three

directions)

There is supporting evidence to indicate a significant difference between the anterior reach direction for the Star Excursion Balance Test compared to the Y Balance Test. Evidence also supports that the protocol for the Y Balance Test is more definitive. The reliability of the Y Balance Test is found to be good to excellent while the Star Excursion Balance Test is found to have good reliability. Ultimately, it is the clinicians’ choice on which test to use when evaluating dynamic neuromuscular control and unilateral balance. Based on these findings, the strength of the recommendation is listed as a grade two. Strength of Recommendation: Although all four of these studies are cohorts, two studies compare the balance tests and two studies look at the reliability of each test. Therefore, the strength of evidence is a grade two. The two studies comparing the balance tests show a significant difference in the anterior reach direction, determining the tests should not be used interchangeably.

Search Strategy

Study Design Coughlan et al. (2012)1 Cohort Study

Gribble et al. (2013)2 Cohort Study

Plisky et al. (2009)3 Cohort Study

Fullam et al. (2014)4 Cohort Study

Participants

20 healthy male participants volunteered. Inclusion criteria: required 18 – 30 years of age, and active three times a week. No history of lower limb injury, neurologic or balance disorder, or fracture in the past three months.

29 healthy participants volunteered. 10 men and 19 women 21 – 41 years old No musculoskeletal injuries or any other condition that would preclude completion of the tests.

15 male collegiate soccer players 17 – 21 years old Exclusion criteria: vestibular disorder, lack of medical clearance, injury, undergoing treatment for inner ear, sinus, upper respiratory infection or head cold, or cerebral concussion within the previous three months.

15 healthy male and 14 healthy females volunteered. Inclusion criteria: 18 – 30 years old, no history of a lower limb injury in the past three months and no history of neurological, balance disorder, or lower limb fracture.

Intervention Investigated

Participants were randomized for test, testing leg and direction each session. All testing was performed barefoot to eliminate additional stabilization and balance. Demonstration was performed for each participant. Four practice trials each direction on each leg then two minutes rest. After the rest, three test trials were conducted in each direction. Testing sessions were completed the same time to minimize the diurnal variation in postural stability.

Each rater was instructed how to perform the SEBT . A script and a standardized demonstration were used. The investigator was the model for each rater to establish proper instructing and measurements. Each participant was tested by all three of the raters on the SEBT. Test order and stance leg was randomized. A verbal and visual demonstration was given from the first rater. Four practice trials in each direction followed by three test trials for each rater in all three directions. Five minute break between each rater was given. Reach directions were anterior, posteromedial, and posterolateral. Testing was performed either barefoot or in socks.

Instructional video was shown for demonstration and explanation. Six practice trials on each leg in all three directions. The subjects were tested within 20 minutes of practicing. All participants wore athletic shoes during the test. Three trials were performed in each direction with the right foot in the anterior direction then the left foot. Then the right foot was tested in the posteromedial direction, followed by the left foot. This repeated for the posterolateral direction. All testing was observed and scored by two raters. Once three trials were performed, the participant would move to a different direction if both raters had at least one successful trial.

Participants were randomized to perform the Star Excursion Balance Test (SEBT) or the Y Balance Test (YBT) first. Participants were instructed to reach with their non-dominant leg and test directions randomized for both tests. All testing was conducted barefoot . Test was demonstrated before the four practice trials in each direction while standing on the dominant leg, with a two minute break. Then three test trials were performed for the three directions. Kinematic data was acquired at 200 Hz using three CODA cx1 units.

Outcome Measures

The reach distances for all testing trials for the right and left legs were recorded for the three directions of the Y Balance Test and the Star Excursion Balance Test.

Normalized and non-normalized (leg length) reach distances were recorded for each leg and each reach direction for the two raters.

The greatest successful reach for each direction and each rater was used for analysis. Also, a composite score was analysis to determine overall performance.

Kinematic profiles of the sagittal plane lower limb were recorded using a 3D motion analysis system. Along with reach distances in all three directions for both tests.

Main Findings Differences were found when comparing the SEBT to the YBT in the anterior reach direction . The right leg had a P value = 0.003 while the left had a P value = 0.0002. The Bland-Altman analysis showed that the 95% limit of agreement between the two balance tests in the anterior direction—ranging from -4.69% to 14.85% for the left leg.

The inter rater reliability was excellent for all 16 measurements taken in this study. The data that was divided by the leg length, or normalized, had an intra class correlation coefficient (ICC) that ranged from 0.86 to 0.92. The data that wasn’t divided by the leg length, or the non-normalized, was stronger and had an ICC ranging from 0.89 to 0.94. The inter rater reliability of the leg length measurement was excellent.

The intra rater reliability of the YBT for one tester ranged from 0.85 to 0.91, with an anterior reach reliability of 0.9, posteromedial of 0.85, posterolateral of 0.90, and a composite score of 0.91.

Inter rater reliability between the two testers ranged from 0.99 to 1.0. The anterior, posteromedial, posterolateral, and the composite score reach were all 0.99.

Significant difference in sagittal plane hip joint angular displacement at maximum reach between the SEBT and the YBT. The SEBT angles were 20.37° ± 18.63° and YBT angles were 28.32° ± 13.19°. The Bland-Altman test showed that the 95% limit of agreement between the balance test in the anterior direction ranging from -0.35% to 14.97%.

Level of Evidence 2b 2b 2b 2b

Validity Score N/A N/A N/A N/A

Conclusion In this study, there was a difference in reach distance with the anterior direction of the test between the SEBT and the YBT. There were no differences with the posterolateral or posteromedial directions between the tests. Postural control strategies influenced the testing outcomes when completing the two tests. Since a difference was found in one direction, the reach distances are not transferrable between tests.

Multiple trained and experienced raters have shown that the SEBT is a reliable test. This is a reliable and inexpensive tool in the clinical and research settings as long as the clinician has received instruction and practice with the SEBT.

According to this study, the YBT reliability ranges from good to excellent due to the standardized equipment and methods. Now that the reliability of the test has been established, clinicians can determine deficits and asymmetries in patients more effectively and confidently. The YBT may also assist clinicians with the return to play process.

Based on the results of this study, there are differences in the anterior direction reach distance during the performance of the SEBT and the YBT. There is also a difference in the angle of the hip at maximum reach. Looking at the sagittal-plane, the angular displacement of the hip is different between the two balance tests. These differences indicate that the SEBT and the YBT cannot be used interchangeably.