Does Dual Motor Tasks Provokes Posture Adaptations in Healthy Young Adults? A Cross-sectional Study

Introduction: Most studies on postural deviations during single and dual tasks have been extensively studied in neuromuscular and older adult populations. Nevertheless, further research is warranted to identify whether such tasks can impose postural adaptations in young, healthy adults without sensory impairments. Aim: To assess postural stability modifications in young adults during single tasks and dual motor tasks (holding a cup filled with water) while concomitantly challenging the sensory systems. Materials and Methods: This was the cross-sectional study on 82 young adults (18-45 years old) from Texas Woman's University (TWU) Health Science Center in Dallas, Texas, and surrounding areas. Standing postural control was measured by collecting total sway, direction of sway and velocity in the Anterior-Posterior (AP) and Medial-Lateral (ML) directions during different balance tasks. For single and dual tasks, the tests were performed with a bipedal stance on foam involving challenging the sensory input via Eyes Open (EO), Eyes Closed (EC), and head movements with eyes open (EO HUD) and closed (EC HUD). The dual motor tasks were similar to the single tasks with the addition of holding a cup full of water to split attention. Data were placed into the Statistical Package for Social Sciences (SPSS) Data Analysis 25.0 system and were analysed for repeated measures Analysis of Variance (ANOVA) analysis. Results: Eighty-two healthy young adults participated in this study (mean age of 24.6 +/- 2.7 years, 13 males and 69 females). An ANOVA analysis revealed that postural stability was considerably altered during motor tasks. Sway in the Antero-Posterior (AP) direction, and velocity of sway increased as the complexity of the tasks intensified. A substantial difference in total sway during single tasks when eyes were closed compared to eyes open (p-value <0.01) was noted. There was a significant difference in total sway (AP and ML) during eyes open (EOM) to eyes closed (ECM) and during eyes open with head moving up and down (EOM HUD) (p-value 0.001). There were significant differences in mean AP velocity during EO (0.11 +/- 0.12) compared to EC HUD (0.19 +/- 0.15), and when comparing EOM (0.07 +/- 0.04) to ECM HUD (0.13 +/- 0.08) (p=0.01) Conclusion: This study identified postural changes when comparing single and dual tasks in healthy young adults, and the outcomes of this study showed definite distinctions in postural responses during single and dual motor tasks.