Introduction: Relevance and Applicability This article is highly pertinent for sport coaches and strength and conditioning (S&C) professionals due to its focus on the relationship between sprinting loads and hamstring strength, a crucial factor in injury prevention, especially in football where hamstring injuries are prevalent. Given that hamstring strains typically occur during high-velocity sprinting and are associated with reduced eccentric strength, understanding how trai

When an athlete performs a jump on a force plate, the movement can be divided into two key phases [although can be broken up into more phase]: the eccentric and concentric phases , each characterized by distinct muscular actions and force patterns. The eccentric phase involves the rapid lengthening of muscles as the body lowers , during which the force plate captures the braking forces applied to decelerate the body's descent. This phase is important for force generation and

The impetus for this study stemmed from the frequent and misleading practice in sport science to use the Reactive Strength Index (RSI) and its modified version (RSI-mod) interchangeably when assessing reactive strength and agility across athlete populations. While both terms share similar nomenclature, RSI is calculated from depth jump (DJ) performance, featuring high-impact and short ground contact times, whereas RSI-mod is derived from countermovement jump (CMJ), which invo