Single-leg Wingate Test in children: reliability and optimal braking force.

Abstract

Single-leg cycle ergometry employing the protocol of the Wingate Test (WAnT) has been used to assess unilateral muscle power and leg-dominance. The objectives of this study were to determine the reliability of the single-leg WAnT (SLWAnT) and to establish optimal braking force for the SLWAnT. Twenty female and 19 male subjects (prepubertals: 6.0-9.9 yr, 7 female and 6 male; midpubertals: 11.0-14.9 yr, 7 female and 7 male; and postpubertals: 17.0-20.9 yr, 6 female and 6 male) came to the laboratory on three occasions. On each visit, they first performed two SLWAnT after a standardized warm-up, one with each leg. Braking force for these tests was kept constant throughout all visits. On each of the following visits, subjects performed four additional SLWAnT, two with each leg, with braking force varying from test to test to determine the braking force associated with the highest performance over 30 s. Although a significant increase in performance was observed from visit to visit in some groups, intraclass correlation coefficients (which included trial-to-trial differences) of peak power and total work generated during the first two SLWAnT of each visit ranged from 0.89 to 0.98. Optimal braking force (J x rev(-1)) could be estimated from 0.4052 x body mass(1.4662) for all subjects irrespective of gender or maturity. The standard error of estimate was lowest in the prepubertals and highest in postpubertals (8.3-31.4 J x rev(-1)). SLWAnT is a highly reliable method to measure single-leg power. The above equation provides good estimates of optimal braking force. The SLWAnT can, therefore, be used to monitor changes in single-leg power and to assess leg-dominance.