Examining The Relationship Between Controlled Targeted Assessments And Flying 30-meter Sprint Performances

INTRODUCTION: The analysis of human movement allows for a deeper understanding of both performance enhancement and injury risk. With the development of markerless motion capture (MMC) technologies, an increased ability to examine unimpeded dynamic athletic movements now exists. With lower financial barriers, controlled targeted assessments are commonly utilized to measure lower extremity strength and power. However, further investigation is needed to understand how these tests are related to dynamic athletic movements. PURPOSE: To determine the relationship between the peak kinetic variables that affect sprint performance and peak forces produced during controlled targeted assessments. METHODS: Ten collegiate sprinters completed a series of flying 30-meter sprints, Eccentric Nordic Hamstring (ENH), Counter Movement Jump (CMJ) and Single Leg Counter Movement Jump (SLCMJ) assessments. Peak hip extension moment (HEM), peak knee extension moment (KEM) and movement velocity were assessed for the flying 30-meter sprints between the 20 and 30-meter marks, using a MMC system synchronized with in-ground force plates. Peak hamstring eccentric force and GRF were measured during the ENH and both CMJ variations, respectively. A one-tailed Pearson correlation was used to compare the sprinting and controlled assessments' metrics. All kinetic metrics were normalized to body weight, with a significance level set at p ≤ .05. RESULTS: Movement velocity had a large correlation with HEM (r = .875 p < .001), but a nonsignificant correlation with KEM (r = .247, p = .246). The peak force produced by each leg during the ENH and SLCMJ had a moderate to large correlation with HEM (r = .425, p = .031; r = .508, p = .011). However, only the SLCMJ was co-correlated with both HEM and movement velocity (r = .695, p = .013). The absolute difference in peak force between legs during the SLCMJ assessment, did not show a statistically significant correlation with the absolute difference in HEM between legs during sprinting (r = -.403, p = .124). CONCLUSION: The peak force produced during a SLCMJ may be used as an indicator for HEM and movement velocity during sprinting. However, this controlled targeted assessment has limitations in its ability to demonstrate the same kinetic imbalances present during a sprinting task.