The Validity of the Modified Star Excursion Balance Test as a Predictor of Knee Extensor and Hip Abductor Strength

Abstract

Objectives:To test the construct validity of the modified Star Excursion Balance Test (SEBT) in predicting the strength of knee extensors and hip abductors and to compare performance between dominant and non-dominant legs.Strength, as measured using hand held dynamometry, has been used as one of a variety of measures in order to subgroup patients with patellofemoral pain. This method is not well received in clinical practice due to time constraints and cost. In contrast, the SEBT is a quick and simple functional measure of dynamic stability. This study examined the validity of the SEBT as an alternate strength measure.Design: Within subject correlation. Each participant recorded maximum isometric contractions for hip abduction and knee extension using a HHD and performed the modified SEBT, on both legs, within one test period. Paired t tests were used to compare dominant and non-dominant legs and Pearson's correlation analyses were used to explore for associations. Setting: Non-clinical environment,Participants: Eighteen healthy male amateur runner's between 18 and 39 years old (mean age 36.1 years). Main outcome measures:Knee and hip moments normalised for leg length (Nm/m) for the HHD and percent of leg length reach score for each SEBT reach as well as a composite of all three.Results: There was no significant difference between dominant and non-dominant legs for all the tests (knee extension p = 0.72, hip abduction p = 0.90, SEBT composite p = 0.86) therefore data was combined into one set. There was no significant relationship between either hip abduction strength (r = 0.28, p = 0.11), or knee extension strength (r= 0.16, p = 0.17), with any combination of the SEBT. A moderate relationship (r = 0.52, p = 0.38) between hip abduction and SEBT posterolateral reach was seen, however, this was not statistically significant. Conclusion:There was no statistically significant association between either knee extension or hip abduction strength with the modified SEBT. This suggests that strength is unlikely to be a primary construct of the test and the SEBT is not a useful replacement for the HHD when testing strength.

The Influence of Fatigue on Star Excursion Balance Test Performance in Dancers

“…The percentage contribution of limb length was calculated as the sum of the three distances for non-dominant and dominant limb, respectively, divided by 3. 28 A paired samples t-test was used to analyze the difference between both RPE and heart rate at stages 1 and 5. The percentage change was calculated between stages 1 and 5, and means, standard deviations, and confidence intervals were recorded.…”

“…Foot length (cm) was measured and the distance reached was normalized to limb length by the following calculation: excursion distance ÷ limb length x 100 = percentage maximized reach distance. 28…”

The relationship between the functional movement screen, star excursion balance test and the Beighton score in dancers

“…The distance reached was normalised to limb length by the following calculation: excursion distance ÷ limb length x 100 = Percentage maximised reach distance [34]. SEBT percentage composite scores was calculated by the sum of the three distances for non-dominant and dominant limb respectively divided by 3 and multiplied by 100 [36]. The performance of the SEBT has been found to stabilise by the 4th practice trial 17 and therefore reach distance was recorded on the 5 th trial.…”