Countermovement Jump Force-Time Curve Analysis between Strength-Matched Male and Female Soccer Players.

Christopher Thomas,Thomas Dos’Santos,Paul A Jones

doi:10.3390/ijerph19063352

Abstract

The purpose of this study was to compare countermovement jump force–time measures between strength-matched male and female soccer players. Males (n = 11) and females (n = 11) were strength-matched via isometric mid-thigh pull testing, whereby peak force values were normalised to body mass. Subjects performed three maximal-effort countermovement jumps (CMJs) on a force platform from which a range of kinetic and kinematic variables were calculated via forward dynamics. Thereafter, differences in gross measures were examined via independent t-tests, while differences in force–, power–, velocity–, and displacement–time curves throughout the entire CMJ were analysed using statistical parametric mapping (SPM). Jump height, reactive strength index modified, propulsion mean force, propulsion impulse, and propulsion mean velocity were all greater for males (d = 1.50 to 3.07). Relative force– and velocity–time curves were greater for males at 86–93% (latter half of the concentric phase) and 85–100% (latter half of the concentric phase) of normalized movement time, respectively. Time to take-off, braking phase time, braking mean velocity and impulse, propulsion phase time and centre of mass displacement were similar between males and females (d = −0.23 to 0.97). This research demonstrates the strength of SPM to identify changes between entire force-time curves. Continued development and the use of SPM analysis could present the opportunity for a refined comparison of strength-matched male and female CMJ performance with the analysis of entire force–time curves.

Highlights

Accepted: 3 March 2022Vertical jump tasks, such as the countermovement jump (CMJ) have been frequently researched and are commonly used to assess and monitor the capacity of the lower body to produce impulse in team and individual sports [1–4]
Typical variables derived from CMJ testing using force platforms including jump height, peak force, peak power, peak velocity, time to take-off, and rate of force development have been used to monitor training outcomes, fatigue and overtraining potential, and readiness to train [1,6,7]
Within-session-reliability of all isometric mid-thigh pull (IMTP) and CMJ variables was good to excellent

Summary

Introduction

Accepted: 3 March 2022Vertical jump tasks, such as the countermovement jump (CMJ) have been frequently researched and are commonly used to assess and monitor the capacity of the lower body to produce impulse in team and individual sports [1–4]. The CMJ induces minimum fatigue, requires minimum familiarization, and is highly reliable [5], demonstrating its usefulness in elite sport as part of ongoing performance and monitoring assessments. Typical variables derived from CMJ testing using force platforms including jump height, peak force, peak power, peak velocity, time to take-off, and rate of force development have been used to monitor training outcomes, fatigue and overtraining potential, and readiness to train [1,6,7]. Numerous attempts have been made to identify differences in performance measures between males and females [3,4,8–10], yet it is questionable whether a lack of control or consideration of physical capacity (e.g., strength) potentially confounds much of this research [11,12]. Prior evidence suggests that males demonstrate greater jump height [9], relative peak concentric force [10], eccentric impulse [3], propulsive impulse [13], and peak power than females.

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Conclusion