Single-Task vs. Dual-Task: Age Differences in Balance and Cognition

Introduction In many everyday situations, motor and cognitive tasks are managed as a dual-task (DT). Studies show performance losses in DT compared to single-task (ST). Against this background, the question arises as to what role age plays. This study examined differences in balance and cognitive performance between ST and DT as well as changes with age. Material and Methods 32 healthy adults (16 each aged 18–30 and 55–67 years) participated in the experimental cross-sectional study. Conditions and pathologies that significantly impair balance were considered exclusion criteria. Three tests were carried out, each lasting 30 seconds with a two-minute break. The ST tasks consisted of a standardized single-leg stand (eyes open) and serial-seven calculations. The third test combined both tasks into a DT task. The number of correctly solved arithmetic problems served as the outcome of the cognitive task. The Moticon OpenGo sensor insole system recorded balance during the motor task using Centre-of-Pressure path length (PL) and sway velocity (SV). The assumption of normal distribution of the data was checked using the Shapiro-Wilk test. Depending on the distribution, effect sizes and their significance were calculated using the t-test or – if the normal distribution was not met – the Mann-Whitney U or Wilcoxon test. Results An analysis of the total sample showed no significant difference with a small effect size between ST and DT in PL (3.44±1.06m to 3.55±0.94m; p=0.161; d=0.25) and SV (119.37±33.96m/s to 122.54±36.12m/s; p=0.117; r=0.277). The changes (DT minus ST) of younger and older adults showed no significant deviations in PL (0.07±0.35m to 0.16±0.53m; p=0.836; r=0.037) and SV (2.34±11.49m/s to 4.01±30.54m/s; p=0.865; r=0.030). There were no significant differences in cognitive arithmetic performance, either in the total sample or specific to age groups. Summary From a clinical perspective, the combination of single-leg stance and the cognitive task difficulty in the present study—analogous to the results of comparable studies—represented a moderate requirement that did not cause significant cognitive-motor interference in healthy adults of different ages.