Measurement bias in estimates of system power during a vertical jump.

Autor: Williams, Kym J., Chapman, Dale W., Phillips, Elissa J., Ball, Nick B.
Předmět:
Zdroj: Sports Biomechanics; Feb 2022, Vol. 21 Issue 2, p226-238, 13p
Abstrakt: This investigation sought to quantify the level of measurement agreement in system force, velocity and power values derived across three commonly applied assessment techniques during a countermovement jump (CMJ). Twenty-five male national representative athletes completed three CMJs under unloaded (0%1RM) and loaded (40%1RM) jump conditions. Associated values of force, velocity and power were captured simultaneously from either a linear optical encoder (LOE) or force plate (FP) and then compared to the gold-standard reference values derived from a combined force plate and three-dimensional motion capture system (FPMC). The LOE significantly (p < 0.001) overestimated and failed to meet the minimum level of relatedness (<0.80) for measures of peak velocity, peak force, peak power and mean power across both conditions compared to the FPMC reference values. A reduction in measurement dispersion and bias was, however, evident during the loaded condition. The FP significantly (p < 0.05) underestimated mean and peak power across both conditions, yet measurement bias and dispersion remained consistent. These findings highlight a disparity in measurement agreement in force, velocity and power values across alternative assessment techniques and loads. Such variance in measurement agreement will uniquely alter derived force-velocity profiles, and thus the prescription of training loads to maximise system power during unrestricted CMJs. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index