Contribution of the dorsolateral prefrontal cortex activation, ankle muscle activities, and coactivation during dual-tasks to postural steadiness: a pilot study

Abstract

[Purpose] To examine the influence of dorsolateral prefrontal cortex (DLPFC) activation, ankle muscle activities, and coactivation on postural steadiness during dual-tasks. [Participants and Methods] A total of 14 participants (8 males, 6 females) were included. The participants stood straight on the force plate, and performed 3 different tasks: 1) a quiet standing (single-task), 2) a repetition of a number (dual-task 1: DT1), and 3) a serial subtraction (dual-task 2: DT2). We divided the participants into 2 groups (S and L group) according to whether their center of pressure paths in the dual-tasks were shorter or longer than those in the single-task. The EMG activity of the gastrocnemius lateralis and tibialis anterior were measured; the oxygenated hemoglobin (oxy-Hb) level in the DLPFC were measured using fNIRS. [Results] The results revealed that oxy-Hb in the left DLPFC increased significantly in all participants during DT2 compared to a single-task. Further, we found that the S group exhibited a higher rate of tibialis anterior activity and ankle muscle coactivation than the L group during DT2. [Conclusion] We concluded that the increase of the DLPFC activation varied with the dual-tasks; moreover, younger individuals modulate their standing posture using different strategies for posture steadiness during posture-calculating task.

Muscular and Prefrontal Cortex Activity during Dual-Task Performing in Young Adults

“…Some similar studies to ours corroborate our results [ 5 , 15 ], but others do not [ 12 ]. For example, a study that assessed the influence of ankle muscle activities, coactivation, and dorsolateral prefrontal cortex activity on postural stability during the dual-task showed a higher tibialis anterior muscle activity and tibialis anterior–gastrocnemius lateralis coactivation in the shorter sway path length group than the longer group.…”

“…For example, a study that assessed the influence of ankle muscle activities, coactivation, and dorsolateral prefrontal cortex activity on postural stability during the dual-task showed a higher tibialis anterior muscle activity and tibialis anterior–gastrocnemius lateralis coactivation in the shorter sway path length group than the longer group. Furthermore, the left dorsolateral prefrontal cortex activity was superior during the performance of the dual-task (performing calculations while standing still) than the single task [ 15 ]. Another study showed a decline in gastrocnemius and tibialis anterior muscle activity during the cognitive dual-task in young and older adults, suggesting a less attentional processing capacity available to the balance control under dual-task conditions [ 5 ].…”

“…On the other hand, studies that assess the cortical activity during a dual-task have been growing in recent years. The prefrontal cortex can play a role in selecting the appropriate motor responses according to various conditions in maintaining balance [ 15 ]. Functional near-infrared spectroscopy (fNIRS) is one of the neuroimage techniques used to analyze the prefrontal cortex activity by measuring the hemodynamic responses of neuronal cortical tissues [ 16 ].…”

“…Therefore, understanding the functional connectivity of the brain and muscle activity during dual-task performance can be a valuable tool for assessing the neuromotor performance of healthy and diseased individuals. Furthermore, to the best of our knowledge, limited studies have compared the EMG of lower-limb musculature during single- and dual-task results [ 5 , 12 ], and fewer combined EMG analyses and prefrontal cortex activity [ 15 ].…”

Effect of transcranial magnetic stimulation on postural control of individuals with major depressive disorder: A case report

“…Although the dorsolateral prefrontal cortex (DLPFC) is primarily associated with executive functions, its role in the control of posture, particularly during cognitively demanding and complex sensory tasks, is well established. [13][14][15][16] Cognitive impairments are shown to impact posture negatively by changing several variables of postural steadiness (e.g. sway velocity) and increasing the risk of accidental falls.…”