Background

Reactive strength index (RSI) is used frequently in the testing and monitoring of athletes. Associations with sports performance measures may vary dependent on the task but a literature synthesis has not been performed.

Objectives

The aim of this meta-analysis was to examine associations between RSI measured during rebound jumping tasks and measures of strength, linear and change of direction speed, and endurance performance.

Methods

A systematic literature search with meta-analysis was conducted using databases PubMed, SPORTDiscus, Web of Science, and Ovid. Inclusion criteria required studies to (1) examine the relationship between RSI and an independent measure of physical or sporting performance for at least one variable; and (2) provide rebound test instructions to minimise ground contact time and maximise displacement of the jump. Methodological quality was assessed using a modified version of the Downs and Black Quality Index tool. Heterogeneity was examined via the Q statistic and I². Pooled effect sizes were calculated using a random-effects model, with Egger’s regression test used to assess small study bias (inclusive of publication bias).

Results

Of the 1320 citations reviewed, a total of 32 studies were included in this meta-analysis. RSI was significantly and moderately associated with strength (isometric: r = 0.356 [95% CI 0.209–0.504]; isotonic: r = 0.365 [0.075–0.654]; pooled strength measures: r = 0.339 [0.209–0.469]) and endurance performance (r = 0.401 [0.173–0.629]). Significant moderate and negative associations were indicated for acceleration (r = − 0.426 [− 0.562 to − 0.290]), top speed (r = − 0.326 [− 0.502 to − 0.151]), and significant large negative associations were noted for change of direction speed (r = − 0.565 [− 0.726 to − 0.404]). Heterogeneity was trivial to moderate across all measures (I² = 0–66%), and significant for isotonic strength and change of direction speed (p < 0.1). Evidence of small study bias was apparent for both acceleration and change of direction speed (p < 0.05).

Conclusions

We identified primarily moderate associations between RSI and independent measures of physical and sporting performance, and the strength of these relationships varied based on the task and physical quality assessed. The findings from this meta-analysis can help practitioners to develop more targeted testing and monitoring processes. Future research may wish to examine if associations are stronger in tasks that display greater specificity.

中文翻译：

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反应强度指数及其与身体和运动表现测量的关联：荟萃分析的系统评价

背景

反应强度指数 (RSI) 经常用于运动员的测试和监测。与运动表现测量的关联可能因任务而异，但尚未进行文献综合。

目标

这项荟萃分析的目的是检查在反弹跳跃任务期间测量的 RSI 与力量、线性和方向速度变化以及耐力表现的测量之间的关联。

方法

使用数据库 PubMed、SPORTDiscus、Web of Science 和 Ovid 进行了系统的文献检索和荟萃分析。纳入标准要求研究 (1) 检查 RSI 与至少一个变量的身体或运动表现的独立测量之间的关系；(2) 提供回弹测试说明，以尽量减少与地面的接触时间并最大限度地增加跳跃的位移。使用唐斯和布莱克质量指数工具的修改版本评估方法学质量。通过 Q 统计量和I ²检查异质性。使用随机效应模型计算合并效应量，使用 Egger 回归检验评估小型研究偏倚（包括发表偏倚）。

结果

在审查的 1320 篇引文中，共有 32 项研究被纳入该荟萃分析。RSI 与力量（等长： r  = 0.356 [95% CI 0.209–0.504]；等渗：r  = 0.365 [0.075–0.654]；综合力量测量：r  = 0.339 [0.209–0.469]）和耐力表现显着和中度相关( r  = 0.401 [0.173–0.629])。加速度（ r  = - 0.426 [- 0.562 至 - 0.290]）、最高速度（r = - 0.326 [- 0.502 至 - 0.151]）显示出显着的中度和负相关 性，并注意到方向变化显着的大负相关性速度（r = - 0.565 [- 0.726 至 - 0.404]）。在所有测量中，异质性都是微不足道的（I ²  = 0-66%），并且对于等渗强度和方向速度的变化具有显着性（p  < 0.1）。对于加速度和方向速度的变化，小的研究偏差的证据是明显的（p  < 0.05）。

结论

我们主要确定了 RSI 与身体和运动表现的独立测量之间的中度关联，并且这些关系的强度因任务和评估的身体质量而异。这项荟萃分析的结果可以帮助从业者开发更有针对性的测试和监控流程。未来的研究可能希望检查关联是否在表现出更大特异性的任务中更强。