Spre-Pubertal Runners Demonstrate Different Temporal-Spatial Parameters Than Mid- and Post-Pubertal Runners

BACKGROUND: Temporal-spatial parameters (TSPs; e.g., cadence, step length) have been associated with running-related injuries in adult long-distance runners. However, it is unknown if TSPs are different among adolescent runners of different physical maturation stages. During sprinting, pre-pubertal runners demonstrated lower cadence and shorter step length than mid- and post-pubertal runners, but TSPs have not been investigated for adolescents of different physical maturation stages when running at submaximal speeds. HYPOTHESIS/PURPOSE: The purpose of this study was to compare TSPs among adolescent long-distance runners of different physical maturation stages. It was expected that pre-pubertal runners would demonstrate a lower cadence and shorter step length than mid- and post-pubertal runners but there would be no differences in TSPs between mid- and post-pubertal runners. METHODS: The study was a cross-sectional design with 93 adolescent long-distance runners (F=48, M=45). Participants were categorized into pre- (n=15, age=10.3±1.6 y), mid- (n=35, age=13.0±1.1 y), and post-pubertal (n=43, age=16.4±1.2 y) physical maturation groups. Participants underwent a three-dimensional running analysis at a comfortable self-selected speed. TSPs (cadence [steps/min], step length [m]) were compared among physical maturation groups using one-way ANCOVA (covariate=running speed) with Sidak pairwise comparisons when a main effect was found (P<.05). RESULTS: The average running speeds for pre-, mid-, and post-pubertal runners were 3.36±0.51 m/s, 3.49±0.71 m/s, and 3.79±0.69 m/s, respectively. ANCOVA analysis showed significant differences in cadence (P<.001) and stride length (P<.001) among physical maturation groups when controlling for running speed (Table 1.1). Pre-pubertal runners had a greater cadence (178±13 steps/min) than mid- (169±12 steps/min, P=.01) and post-pubertal runners (168±11 steps/min, P<.001). Pre-pubertal runners also had a shorter step length (1.13±0.20 m) than mid- (1.24±0.20 m, P=.01) and post-pubertal runners (1.36±0.21 m, P<.001). There were no significant differences between mid- and post-pubertal runners (P>.22). CONCLUSION: When controlling for running speed, pre-pubertal runners demonstrated a greater cadence and shorter step length than both mid- and post-pubertal runners. Lower cadence and longer stride lengths have been associated with running-related injuries in adults. If TSPs have the same association with injury in adolescents as adults, then our study suggest mid- and post-pubertal runners may be at a higher risk of sustaining a running-related injury than pre-pubertal runners due to their lower cadence and longer step lengths. However, prospective research is necessary to better understand the importance of TSPs and running-related injuries in adolescent long-distance runners.