Muscle architecture and maturation influences sprint and jump ability in young boys: a multi-study approach

Abstract

This series of experiments examined the influence of medial gastrocnemius (GM) and vastus lateralis (VL) muscle architecture (muscle thickness, pennation angle, and fascicle length) on sprint and jump performance in pre-, circa- and post-peak height velocity (PHV) boys. In experiment 1, one-way ANOVA’s and Cohen’s d effect-sizes demonstrated that most muscle architecture measures were significantly greater in post- compared to pre-PHV boys (d = 0.77 - 1.41; p < 0.05). For the majority of sprint and jump variables, there were small to moderate differences between pre- to circa-, and circa- to post-PHV groups (d = 0.58 – 0.93; p < 0.05), and moderate to large differences between pre- and post-PHV groups (d = 1.01 - 1.47; p < 0.05). Pearson’s correlation analyses in experiment 2 determined that muscle architecture had small to moderate correlations with sprint and jump performance (r = 0.228 – 0.707, p < 0.05), with strongest associations within the post-PHV cohort. Chi squared analyses in experiment 3 identified that, over 18-months, more POST-POST responders than expected made positive changes in GM and VL muscle thickness. Significantly more PRE-POST subjects than expected displayed changes in maximal sprint speed, while significantly more POST-POST individuals than expected showed positive changes in jump height. Muscle architecture appears to be larger in more mature boys compared to their less mature peers, and likely underlies their greater performance in sprinting and jumping tasks. Boys experiencing, or having experienced, PHV make the largest increases in muscle architecture, and sprinting and jumping performance when tracked over 18-months.