Unplanned movement tasks requiring rapid decision-making: a scoping review of study characteristics and methodological approaches

BACKGROUND: The integration of neurocognitive challenges into biomechanical movement tasks has gained attention due to its potential relevance for assessments of physical function, injury risk, and performance. However, a comprehensive mapping of the chosen methodological approaches, targeted populations, and applied outcome measures is still lacking. This scoping review hence aimed to synthesize the current literature on unplanned movement tasks combining cognitive decision-making and biomechanical outcome measurements. METHODS: A systematic literature search following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses-extension for scoping reviews) guidelines was performed in Web of Science (Core Collection), MEDLINE (PubMed), Cochrane Library, and Google Scholar. Included studies combined unplanned movement tasks (e.g., change-of-direction or stopping) with biomechanical assessments. Eligible articles were analysed in terms of participant characteristics, movement type, unplanned task type, reactive stimulus, and biomechanical outcome variables. RESULTS: From the total of 167 studies, the majority focused on change-of-direction tasks (82%), mostly using standardized angles of 45° and moderate approach speeds (3.9 ± 0.9 m/s). Jump (7%), land (12%), and/or stop tasks (3%) were less frequent. Most studies (83%) relied on simple visual cues (e.g., lights or symbols), whereas more ecologically valid stimuli (e.g., videos or real opponents) were rarely applied. Biomechanical analyses predominantly focused on knee angles and moments as well as ground reaction forces, while only 23% of studies included electromyography measurements. Older adults (50+ years) were not represented. CONCLUSION: Although research on unplanned biomechanical tasks is growing, significant methodological heterogeneity and limited ecological validity may constrain the interpretability and applicability of findings. Future research should aim for task designs that better reflect real-world conditions and include diverse populations and comprehensive neuromuscular assessments.