The impact of a secondary cognitive task on variables associated with ACL loading during landing: a systematic review and meta-analysis

This article aimed to perform a meta-analysis and systematic review on the effect of dual-task landing on potential ACL loading. Repeated measures assessments of landings with concurrent, unrelated cognitive tasks were included. Databases were searched (SPORTDiscus, ScienceDirect and PubMed, searched June 2023). Results were synthesised and presented using custom R code. Twenty-five articles were included, 12 eligible for the meta-analysis, involving single or double-leg landings alongside various cognitive tasks. Funnel plots, regression testing and selection modelling detected no publication bias. The systematic review identified most authors concluded dual-task landing potentially increased ACL loading, due to small, inconsistent, biomechanical impacts on the trunk and lower extremity consistent with potentially increased ACL loading. However, robust variance estimation showed no significant effect (g = -0.001, 95% CI [-0.093, 0.09], <i>p</i> = 0.97) on frontal or transverse plane knee loading, only identifying a small decrease in IC knee flexion angles (g = -0.13, <i>p</i> = 0.03). Diverse research methodologies make summarising this research area difficult. While dual-task landings can evoke mechanical changes associated with potentially increased ACL loading, this increased loading is not consistently seen. Further research with consistent methodologies is required to clarify this. This paper was registered (PROSPERO: CRD42023425191).