Kinematics of assisted and unassisted plyometric training of vertical jumping and rebounding in youth male football players – A six-week training study

Abstract

The purpose of this study was to compare the kinematics of assisted and unassisted plyometric training of vertical jumping and rebounding activities following a six-week training intervention. 13 youth males from a professional football academy completed six weeks of either unassisted (n = 6) or band-assisted (n = 7) plyometric training sessions twice a week during their competitive season. Pre- and post-assessments of counter-movement jump (CMJ) height, 50 cm drop-jump (DJ50) ground contact time (GCT), jump height and reactive strength index (RSI), and submaximal-hopping (SMH) GCT, jump height and RSI were compared. Pre- and post-assessment ankle angle at touch-down (TD), peak flexion (PF) and mid-flight (MF) were also analysed for the submaximal-hop test only. Following training, significant main effects of time were observed for CMJ height, DJ50 GCT and MF ankle angle (p < 0.05) and a significant effect of group was observed for DJ50 RSI (p < 0.05). These results suggest that both unassisted and assisted plyometric training may be useful for enhancing the kinematics and technical performance of plyometric activities in a youth male football population.