Investigation of acute effects of dual tasks in lower extremity amputees

This study aimed to examine the acute effects of dual-task in individuals with lower limb amputation and to compare the outcomes with healthy controls. A total of 32 volunteers participated in the study, including 16 individuals with lower limb amputation and 16 healthy participants selected with similar demographic characteristics. Functional assessment was conducted using the 2-Minute Walk Test (2MWT), Timed Up and Go Test (TUG), and Functional Reach Test (FRT), while cognitive performance was evaluated using the Stroop Test TBAG Form (ST), Trail Making Test (TMT), and Nelson Hand Reaction Test. Autonomic nervous system measurements were obtained using the POLAR H10 device. Participants performed the 2MWT as the primary task and executed simultaneous cognitive and motor tasks as the secondary task. All assessments were administered both before and after the dual-task intervention, and the results were compared. Statistical analyses were conducted using SPSS v.26 (SPSS Inc., USA). Categorical variables were analyzed using the χ² test. For non-normally distributed or ordinal data, the Wilcoxon test was used for within-group comparisons and the Mann–Whitney U test for between-group comparisons. For normally distributed numerical variables, paired samples t-test was used for within-group comparisons, and independent samples t-test was applied for between-group comparisons. Statistical significance was set at p<0.05. In the amputee group, a statistically significant decrease in TUG duration and a significant increase in FRT distance were observed following the dual-task intervention. In cognitive assessments, significant reductions were found in ST-1, ST-3, and TMT A1 durations, whereas a significant increase was noted in ST-3 correction counts. Regarding autonomic responses, the SNS index reflecting sympathetic activity showed a significant increase, while the PNS index indicating parasympathetic activity decreased significantly. In the control group, post-intervention analysis revealed a statistically significant reduction in TUG duration and an increase in FRT distance. Significant decreases were observed in ST sections 1, 3, 4, and 5, as well as in TMT A1, A2, B1, and B2 durations; additionally, a significant reduction was found in the B Form – A Form time difference. However, no statistically significant differences were detected in autonomic nervous system parameters between pre- and post-task measurements. Although both groups showed statistically significant improvements in balance parameters, between-group comparisons revealed a significant difference only in TUG duration in favor of the amputee group. This suggests that the dual-task intervention had a more pronounced effect on dynamic balance. The findings indicated that dual-task practice acutely enhanced attention and executive functions in both groups. However, as inhibition demands increased in the Stroop Test, the tendency to make errors rose among amputee participants, and cognitive gains remained limited. Between-group comparisons revealed a significant difference only in the TMT A1 duration in favor of the amputee group and in the PNS index in favor of the control group. These findings suggest that dual-task interventions may improve basic-level cognitive speed and visuomotor processing skills, but individuals with amputation may have difficulty maintaining parasympathetic balance in response to short-term stress. Overall, the results highlight the necessity of integrative rehabilitation approaches in lower limb amputees that not only target motor skills but also support cognitive functions and autonomic nervous system regulation.