Reactive Strength Index Modified Differentiates Starters and Non-Starters in Female Volleyball National Team Players
Year: 2025
Type: article
Study design: Observational Study
Abstract: Jumping ability is crucial in volleyball, where both jump height and execution speed significantly influence performance. Previous research has yielded mixed findings on the role of jump force-time characteristics in determining starting status among female volleyball players. This study examined the relationship between countermovement jump (CMJ) force-time metrics and starting status in elite female volleyball players to identify key performance indicators. Nine national team athletes (five starters, four non-starters) performed CMJs on a force platform. Force-time variables from distinct jump phases were analyzed. Reactive strength index modified (RSImod)—the ratio of jump height to time to take-off—was used to assess lower-body explosiveness and reactive strength. Starters demonstrated significantly higher RSImod scores and relative propulsive mean force, indicating superior ability to generate force rapidly. Moderate-to-large effect sizes favoring greater relative strength (force and power normalized to body mass) were observed but were not statistically significant. Reactive strength, as reflected by RSImod, is a key differentiator of starting status in elite female volleyball players. Relative strength also appears to contribute to performance but requires further exploration. Training programs should prioritize lower-body power and reactive strength through targeted plyometric and resistance exercises to enhance volleyball performance.
DOI: 10.54392/ijpefs2514
Authors: Idan Harat, Nadav Lanesman
Institutions: Wingate Institute, Ariel University
Language: English
Subfield: Orthopedics and Sports Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4408631483