A novel method to categorise stretch-shortening cycle performance across maturity in youth soccer players

Abstract

This study utilised a novel method to categorise stretch-shortening cycle (SSC) function during a drop jump (DJ) using the force-time curve. This method was then used to determine the effect of maturity status upon SSC function and effect of SSC function on drop jump performance. Pre-, circa- and post-peak height velocity male youth soccer players completed a pre-season 30 cm DJ onto a force plate. SSC function was categorised as poor (impact peak and not spring like), moderate (impact peak and spring like) or good (no impact peak and spring-like). Interactions between SSC function and maturity status, and SSC function and kinetic variables were explored. Youth soccer players displaying good SSC function were older and more mature than those with poor SSC function, however, 9.9% of post-PHV still displayed poor SSC function. Players with good SSC function recorded significantly shorter ground contact times, reduced time between peak landing and takeoff force, reduced centre of mass displacement and significantly greater takeoff forces than players with moderate and poor SSC function (all p < 0.05). SSC function during a standardized DJ improves with maturation, but a portion of mature players still demonstrate poor SSC function. Good SSC function was associated with improved DJ outcome measures except jump height. Tailored training interventions based upon SSC competency may be required to optimally enhance SSC function.