Relationships between Isometric Force-Time Characteristics and Dynamic Performance.

Paul Comfort,Thomas Dos’Santos,John McMahon,Christopher Thomas,Paul Jones

doi:10.3390/sports5030068

Abstract

The purpose of this study was to explore the relationships between isometric mid-thigh pull (IMTP) force-time characteristics (peak force and time-specific force vales (100–250 ms)) and dynamic performance and compare dynamic performance between stronger and weaker athletes. Forty-three athletes from different sports (rowing, soccer, bicycle motocross, and hockey) performed three trials of the squat jump (SJ), countermovement jump (CMJ), and IMTP, and performed a one repetition maximum power clean (PC). Reactive strength index modified (RSImod) was also calculated from the CMJ. Statistically significant large correlations between IMTP force-time characteristics and PC (ρ = 0.569–0.674, p < 0.001), and moderate correlations between IMTP force-time characteristics (excluding force at 100 ms) and RSImod (ρ = 0.389–0.449, p = 0.013–0.050) were observed. Only force at 250 ms demonstrated a statistically significant moderate correlation with CMJ height (ρ = 0.346, p = 0.016) and no statistically significant associations were observed between IMTP force-time characteristics and SJ height. Stronger athletes (top 10) demonstrated statistically significantly greater CMJ heights, RSImods, and PCs (p ≤ 0.004, g = 1.32–1.89) compared to weaker (bottom 10) athletes, but no differences in SJ height were observed (p = 0.871, g = 0.06). These findings highlight that the ability to apply rapidly high levels of force in short time intervals is integral for PC, CMJ height, and reactive strength.

Highlights

Maximum strength is an integral quality unpinning athletic performance [1,2,3], assessing and monitoring the maximum force production qualities of athletes is of great importance to sports scientists and strength and conditioning coaches
The investigation was approved by the institutional ethics review board (HSCR16/36), and all subjects were informed of the benefits and risks of the investigation prior to signing an institutionally approved consent document to participate in the study
The results from this study revealed isometric mid-thigh pull (IMTP) force-time characteristics were statistically significantly correlated to 1RM power clean (PC)

Summary

Introduction

Maximum strength is an integral quality unpinning athletic performance [1,2,3], assessing and monitoring the maximum force production qualities of athletes is of great importance to sports scientists and strength and conditioning coaches. One repetition maximum testing (1RM) of exercises such as the back squat, deadlift, and power clean (PC) are commonly used by practitioners to assess the maximum strength capabilities in athletic populations [2,4,5] and are used to monitor the effectiveness of training and inform future training. The maximal loads lifted are often used as a reference to prescribe training loads for future training, several limitations exist including duration of testing, technical competency, fatigue, and risk of injury [9,10]. An assessment which reduces these limitations and provides greater insight into the maximal and rapid force production capabilities of athletes is the isometric mid-thigh pull (IMTP). PF has been shown to be highly reliable within and between sessions [8,11,14,15,16] and may offer a surrogate to 1RM testing due to its strong associations with 1RM back squat [2,12,17,18,19], PC [17,18,20], deadlift [9], and weightlifting

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Conclusion