Performance and reliability of the Y-Balance Test™ in high school athletes.

BACKGROUND: Lower extremity injuries account for 32.9% of the overall injuries in high school athletes. Previous research has suggested that asymmetry greater than 4 cm using the Y-Balance Test™ Lower Quarter (YBT-LQ) in the anterior direction is predictive of non-contact injuries in adults and collegiate athletes. The prevalence of asymmetries or abnormal YBT-LQ performance is not well documented for adolescents. The primary purposes of this study are: 1) to characterize the prevalence of YBT-LQ asymmetries and performance in a cross-sectional sample of adolescents; 2) to examine possible differences in performance on the YBT-LQ between male and female adolescents; and 3) to describe the test-retest reliability of the YBT-LQ in a subsample of adolescents. METHODS: Observational cross-sectional study. High-school athletes completed the YBT-LQ as main outcome measure. RESULTS: A total of 51 male and 59 female high-school athletes participated in this study. Asymmetries greater than 4cm in the posteromedial (PM) reach direction were most prevalent for male (54.9%) and female (50.8%) participants. Females presented with slightly higher composite scores. Good reliability (ICC=0.89) was found for the anterior (ANT) direction, and moderate reliability with 0.76 for posterolateral (PL) and 0.63 for PM directions. The MDC95 for the ANT direction was 6% and 12% for both the PL and PM directions. CONCLUSIONS: The YBT-LQ performance can be beneficial in assessing recovery in an injured extremity compared to the other limb. However, due to the large MDC95, noted in the PM and PL directions, the differences between sequential testing cannot be attributed to true change in balance unless they exceed the MDC95. In this study, 79% of the athletes presented with at least one asymmetry in YBT-LQ reach distances. Moderate reliability in the PL and PM directions warrants reexamination of the definition of asymmetry in these directions.

Performance of high school male athletes on the Functional Movement Screen™.

OBJECTIVES: (1) Describe the performance of the Functional Movement Screen™ (FMS™) by reporting the proportion of adolescents with a score of ≤14 and the frequency of asymmetries in a cross-sectional sample; (2) explore associations between FMS™ to age and body mass, and explore the construct validity of the FMS™ against common postural stability measures; (3) examine the inter-rater and test-retest reliability of the FMS™ in adolescents. DESIGN: Cross-sectional. SETTING: Field-setting. PARTICIPANTS: 94 male high-school athletes. MAIN OUTCOME MEASURE: The FMS™, Y-Balance Test (YBT) and Balance Error Scoring System (BESS). RESULTS: The median FMS™ composite score was 16 (9-21), 33% of participants scored below the suggested injury risk cutoff composite score of ≤14, and 62.8% had at least one asymmetry. No relationship was observed between the FMS™ to common static/dynamic balance tests. The inter-rater reliability of the FMS™ composite score suggested good reliability (ICC = 0.88, CI 95%:0.77, 0.94) and test-retest reliability for FMS™ composite scores was good with ICC = 0.83 (CI 95%:0.56, 0.95). CONCLUSIONS: FMS™ results should be interpreted cautiously with attention to the asymmetries identified during the screen, regardless of composite score. The lack of relationship between the FMS™ and other balance measures supports the notion that multiple screening tests should be used in order to provide a comprehensive picture of the adolescent athlete.

Predictors of static balance in ambulatory persons with multiple sclerosis.

People with multiple sclerosis (MS) experience a high rate of falls and have decreased static and dynamic balance. The purpose of this study was to determine best predictors of static standing balance, as measured by a single limb stance (SLS) timed test, in ambulatory persons with MS (PwMS) from among commonly used medical and rehabilitation clinical tests. Ambulatory PwMS participated in a single test session. Medical exam data gathered included the Function System (FS) neurologic exam and Expanded Disability Status Score (EDSS). A variety of commonly administered rehabilitation clinical tests addressing static balance, dynamic balance, gait endurance, functional lower extremity strength, abdominal and respiratory muscle strength were completed. Descriptive statistics, Pearson product moment correlations, and forward step-wise linear regressions were calculated. Twenty-eight ambulatory PwMS completed this study. Mean age was 54.74 years. Mean SLS score was 14.6 s. Pyramidal, sensory, bowel/bladder, and visual FS scores and the EDSS were significantly correlated with SLS. Maximal step length scores were significantly correlated with SLS at P less than 0.05 and the Functional Stair Test (FST) and 6-min walk test were correlated with SLS at P less than 0.10. Medical exam data EDSS and FS sensory explain 72.1% of the variance in SLS scores. Rehabilitation exam data FS sensory and FST explain 68.8% of the variance. The FS sensory, EDSS, and FST together explain 73.3% of the variance.

Core muscle strength and endurance measures in ambulatory persons with multiple sclerosis: validity and reliability.

This study examined the test-retest reliability and validity of three core muscle strength tests in individuals with multiple sclerosis (MS). Twenty-one ambulatory individuals with MS completed the curl-up, flexor endurance, and pelvic tilt stabilization tests of core muscle strength. They were retested 1-2 weeks after the first test. The sit-to-stand (STS) test was also conducted on the first test. Descriptive statistics, intraclass correlation coefficients, SEM, and minimal detectable change (MDC) were calculated for each test. Pearson's correlations were calculated between all variables for the first test date. The curl-up test demonstrated excellent test-retest reliability (intraclass correlation coefficient=0.995), requiring 3.4 additional repetitions in 60 s to demonstrate a detectable change. The curl-up test was moderately correlated with the STS. The flexor endurance and pelvic tilt stabilization tests demonstrated moderate test-retest reliability, with relatively large SEMs and MDCs and only a low correlation with the STS. The curl-up test is recommended as a valid and reliable test of core muscle strength in individuals with MS. The flexor endurance test and the pelvic tilt stabilization test of core muscle strength are not recommended due to large SEM and MDC scores. Further study of core muscle strength and endurance measures is indicated to seek additional tests that are valid and reliable in the MS population.