Lower-limb biomechanical alterations across movement tasks in individuals with chronic ankle instability: An umbrella review of systematic reviews and meta-analyses.

Chronic ankle instability (CAI) may reflect altered regulation of mechanical loading and neuromuscular control across the lower limb, but review-level evidence remains fragmented by task and outcome. This umbrella review synthesised systematic reviews and meta-analyses on biomechanical and neuromuscular alterations during movement tasks in individuals with CAI, functional or mechanical ankle instability, recurrent ankle sprain, or ankle-sprain copers. PubMed/MEDLINE, Scopus, Web of Science Core Collection, selected EBSCOhost databases, the Cochrane Library, and ScienceDirect were searched; 18 reviews were included, of which 17 informed the main synthesis and one contributed supplementary dual-task evidence. Evidence was most concentrated for landing and jump-landing tasks, where reduced pre-landing peroneal activation, greater or faster vertical loading, and stiffer sagittal-plane landing mechanics were commonly reported. Walking evidence suggested greater ankle inversion, hip adduction, and knee valgus moment, whereas perturbation landing evidence suggested delayed peroneus longus activation and greater inversion mechanics. Coper comparisons may suggest more preserved task-specific movement profiles after ankle sprain. Overall, the evidence base is sufficient to identify recurring patterns of altered lower limb biomechanics in CAI, but insufficient to support highly definitive conclusions for most task outcome domains. Protocol registration: PROSPERO CRD420261454010.