Limb-Specific Associations Between Isokinetic Knee and Hip Variables and Contact Time Across Sprint Phases in Elite Sprinters

Abstract

This study examined exploratory associations between isokinetic knee and hip variables and video-derived contact time across sprint acceleration. Nineteen male sprinters completed 60 m sprints; photocell timing gates recorded sprint times, and eight high-speed cameras operating at 240 frames/s provided contact and flight times. Bilateral concentric knee and hip flexion-extension were assessed at 60 degrees/s and 240 degrees/s for peak torque, relative peak torque, peak power, relative peak power, time to peak torque, and joint angle at peak torque. No statistically significant inter-limb differences were detected in the four torque/power outcomes or mean contact time. Two exploratory knee-extension comparisons at 240 degrees/s yielded nominal raw p values below 0.05 for joint angle and time to peak torque, but neither remained statistically significant after Benjamini-Hochberg correction across 16 temporal/angular comparisons. After correction within four complete correlation families, 4 of 26 sprint-time-contact-time correlations remained statistically significant, all involving non-dominant-limb contact time. None of the 832 torque-contact-time, 832 power-contact-time, or 832 time-to-peak-torque/joint-angle-at-peak-torque-contact-time correlations remained significant. The isokinetic correlation patterns are therefore exploratory and require confirmation in larger samples using contact-time methods with established reliability and adequate temporal precision.