The effect of body size on countermovement jump kinetics in children aged 7-11 years

The purpose this study was to examine the effect of body size on countermovement jump (CMJ) kinetics in children. Participants (n = 160) aged 7-11 years, divided equally by sex and into primary school year groups (years 3, 4, 5 and 6), each performed one CMJ on a force platform. The variables bodyweight (BW), peak force (Fmax), in-jump minimum force (IMF), in-jump vertical force range (IFR) and basic rate of force development (BRFD) were attained from the force-time history and then subsequently scaled to account for body size. A significant age, sex and interaction effect were found for the absolute variables BW, IMF, Fmax and IFR (P