Longitudinal changing relationships between growth tempo and vertical stiffness in movement across maturation.

ABSTRACT

PURPOSE: To determine whether average growth tempo influenced longitudinal relationships between maturity status and coordination capability using a 15-s hopping task (Aim 1). To investigate how differences in absolute growth tempo were associated with change in coordination capability within and across peak growth (Aim 2). METHODS: Participants were N1 = 110 (Aim 1) and N2 = 71 (Aim 2) Australian male competitive swimmers, aged 10-15 years, exposed to repeated-measures tracking (2-years, and 12-months respectively) of maturity status, growth tempo and movement coordination capability. Coordination capability was estimated via vertical stiffness (KV) in a hopping task, reflected by participant mean KV and between-jump coefficient of variation (CV). RESULTS: For Aim 1, log-linear mixed model trends identified maturity status and growth tempo were significantly associated with KV mean and KV CV. For a given maturity status, mean KV was 9% lower in the 'High' average growth tempo group than the 'Low' average tempo group. For Aim 2, mixed repeated-measures analyses of variance identified how time points of increased growth tempo were significantly associated with 7-11% reductions in mean KV, with similar mean KV decrements irrespective of growth tempo group. Meanwhile, KVCV only illustrated progressive longitudinal reductions. CONCLUSIONS: Within maturational progression, short-term accelerations in growth tempo corresponded with short-term decreases in KV mean, suggesting temporary disruptions to movement coordination capability. Measuring growth tempo and applying hopping tasks in specific movement contexts could help consistently identify disturbances in motor coordination.