Abdominal Muscle Performance as Measured by the Double Leg-Lowering Test

Abstract

Krause DA, Youdas JW, Hollman JH, Smith J. Abdominal muscle performance as measured by the double leg-lowering test. Objective To describe abdominal muscle performance as measured by the double leg-lowering test (DLLT) in healthy subjects. Design Repeated measures. Setting Academic laboratory. Participants A sample of 100 healthy volunteers (50 men, 50 women; age range, 18–29y). Interventions Not applicable. Main Outcome Measures Repeat measurements of the DLLT to determine reliability and performance standards and to identify variables that predict performance. Results The intraclass correlation coefficient (ICC 3,1) for repeated measures of the DLLT was .98. The mean value ± standard error of the mean for abdominal performance for men was 15.4°±2.3° from a horizontal reference, and for women it was 36.9°±3.4°. A significant difference was found between men and women on performance of the DLLT ( t 98=−5.3, P<.001). A linear regression model found sex ( t=−3.2, P=.002) and age ( t=−4.6, P<.001) to be significant predictors of performance on the DLLT. Conclusions The DLLT has excellent intratester reliability. We also found a sex difference in the performance of the DLLT.