School of Biosciences and Medicine, University of Surrey, Guildford,United Kingdom.
Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff,United Kingdom.
Int J Sports Physiol Perform. 2023 Jul 27;18(9):1012-1018. doi: 10.1123/ijspp.2023-0090. Print 2023 Sep 1.
This study sought to quantify the within-individual relationships between spatiotemporal variables and initial acceleration sprint performance in elite rugby backs and to establish a normative data set of relevant strength-based measures.
First, the spatiotemporal variables, ratios of step length to step rate and of contact time to flight time, and initial acceleration performance were obtained from 35 elite male rugby backs (mean [SD] age 25 [3] y) over the first 4 steps of 3 sprints. Angular and linear kinematic aspects of technique and strength-based qualities were collected from 25 of these participants. Second, the same spatiotemporal variables were collected from 19 of the participants on 3 further occasions (12 trials in total) to determine the within-individual associations of these variables and initial acceleration performance.
Moderate to very large meaningful within-individual relationships (|r| = .43-.88) were found between spatiotemporal variables and initial acceleration performance in 17 of the 19 participants. From these relationships, a theoretically "desirable" change in whole-body kinematic strategy was individually determined for each participant, and normative strength-based measures to contextualize these were established.
Meaningful within-individual relationships are evident between sprint spatiotemporal variables and initial acceleration performance in elite rugby backs. Individualized approaches are therefore necessary to understand how aspects of technique relate to initial acceleration performance. This study provides an objective, evidence-based approach for applied practitioners to identify the initial acceleration technical needs of individual rugby backs.
本研究旨在量化个体内时空变量与精英橄榄球后卫初始加速冲刺表现之间的关系，并建立相关力量测量的规范数据集。
首先，从 35 名精英男性橄榄球后卫（平均[SD]年龄 25[3]岁）的 3 次冲刺的前 4 步中获取时空变量、步长与步频比和触地时间与腾空时间比，以及初始加速度性能。从其中 25 名参与者中收集了技术和基于力量的特征的角度和线性运动学方面的信息。其次，19 名参与者在另外 3 次（总共 12 次试验）中收集了相同的时空变量，以确定这些变量与初始加速表现的个体内相关性。
在 19 名参与者中的 17 名参与者中，时空变量与初始加速表现之间存在中度到非常大的有意义的个体内相关性（|r|=.43-.88）。从这些关系中，为每个参与者单独确定了整个身体运动学策略的理论上“理想”变化，并建立了规范的基于力量的措施来对其进行上下文化。
在精英橄榄球后卫中，冲刺时空变量与初始加速表现之间存在有意义的个体内关系。因此，有必要采用个体化方法来了解技术方面如何与初始加速表现相关。本研究为应用实践提供了一种客观、基于证据的方法，可用于确定个体橄榄球后卫的初始加速技术需求。
