Do the characteristics of concurrent task influence the dual-task interference during functional mobility in young adults with intellectual disability?

Objectives Daily activities require managing various dual-task (DT) situations. The aim of this study was to explore DT (DTI) during functional mobility in adults with intellectual disability (ID) and to investigate whether the nature of the secondary tasks modulates the degree and pattern of this interference.Methods Twelve male adults with ID (IDG) and ten male controls (CG) performed the Timed Up and Go Test (TUGT) under single-task (ST), DT motor (DT-motor), and three DT cognitive conditions: verbal fluency (DT-VF), forward digit recall (DT-FD), and backward digit recall (DT-BD). Performances in secondary tasks were also assessed under ST conditions, and DT-costs (DTC) were calculated.Results The TUGT and the secondary task performances deteriorated (p < 0.001) in all DT conditions compared to ST for both groups. The IDG exhibited higher (p < 0.001) DTC compared to the CG. In the IDG, DTC was higher during DT-motor than during DT-VF and DT-FD (p < 0.001), but it did not differ from DT-BD (p = 0.36). In the CG, DTC was higher during DT-BD compared to DT-motor and DT-FD (p < 0.001), but similar to DT-VF (p = 0.45).Conclusions A mutual DTI was observed in both groups, with the amount dependent on the secondary task. Heightened DTI in individuals with ID underscores the need for task-specific strategies in DT assessments and interventions.