Exploring the Relationships between Phase-Specific Change of Direction Performance and Anterior Cruciate Ligament Injury Risk: A Pilot Study: A cross-sectional study assessing elite and sub-elite female handball players in the modified 505 test

Abstract

Background: Change of direction (CoD) ability is vital for elite performance in multidirectional sports (MDS). A CoD in its´simplest form (i.e., one turn) consist of distinct subphases (initial acceleration, deceleration, re-acceleration) that impose different demands often overlooked in traditional CoD tests as they quantify overall time. Of concern, decelerations and CoDs are closely associated with non-contact ACL injuries. As practitioners, we have a dual responsibility to optimize performance and concomitantly minimize injury risks. While research traditionally has emphasized CoD biomechanics of injury risk and performance independently, recent findings underscore the significance of examining them concurrently. Presently, our understanding of the relationship between phase-specific CoD performance and knee joint loading is limited. It is particularly important to explore the role of deceleration ability, which serves as a critical subphase influencing both CoD performance and knee joint loading. Given the current gaps in our knowledge, conducting further research in this area becomes imperative. Purpose: Investigate relationships between phase-specific CoD performance and knee joint injury risk during the modified 505 test (m505 test).

Methods: Seventy-seven elite and sub-elite female handball players were tested in the m505 CoD test. Kinematic and kinetic data were recorded with a motorized resistance device (MRD), force platforms, and infrared Opus cameras. Knee abduction moment (KAM) was calculated as a proxy of knee joint injury risk. Subphases (initial acceleration, deceleration, early and late deceleration, and re-acceleration) of the m505 test were analyzed. Performance variables included time, distance, velocity, acceleration, force, power, and impulse. Relationships between KAM and outcome measurements were determined using correlational analysis and a linear backward regression analysis. Furthermore, group comparison based on a median split between High vs. Low KAM and Fast vs. Slow CoD was explored using independent samples t-test or Mann-Whitney U test. Cohen’s d effect sizes were calculated to evaluate the magnitude of differences between groups.

Results: Moderate to trivial correlations were observed between KAM and phase-specific CoD performance variables (r  0.41). Total, entry and phase-specific times did not correlate with KAM (r < 0.3). A combination of phase-specific CoD performance variables could explain 22,6 % of the variance in KAM. There were no differences in entry and overall CoD times between the High and Low KAM groups. Moderate effect size differences were observed between the groups in maximal entry velocity and variables of deceleration performance, with greater values demonstrated by the High KAM group. The Fast and Slow groups exhibited similar KAMs, while the faster athletes achieved quicker CoD times primarily due to their superior initial acceleration and late deceleration performance.

Conclusion: There is no significant relationship between KAM and faster CoD times in the m505 test. Greater entry velocity and deceleration performance are moderately in conflict with lower KAMs. Phase-specific CoD performance variables contribute to the understanding of KAM; however, these variables cannot accurately predict KAM independently. These findings suggest that additional variables should be assessed when investigating knee joint injury risk during 180° cutting.