Postural Control in Dual-Task Situations: Does Whole-Body Fatigue Matter?

Area of Science:

• Human movement science
• Neuroscience
• Exercise physiology

Background:

• Postural control is vital for daily activities.
• Attentional demand and fatigue are known to negatively impact postural control in young adults.
• The combined effects of fatigue and attentional demand on postural control remain unclear.

Purpose of the Study:

• To investigate the combined effects of physical fatigue and attentional demand on postural control.
• To compare postural control under single-task (ST) and dual-task (DT) conditions in both fatigued and non-fatigued states.

Main Methods:

• Twenty young adults underwent an incremental treadmill test to induce fatigue.
• One-legged stance balance was assessed using a force platform under ST and DT conditions (serial subtractions).
• Balance tasks were performed in both fatigued and non-fatigued (control) states on separate days.

Main Results:

• Fatigue significantly increased heart rate, lactate, and ventilation.
• Postural sway and sway velocity were significantly higher in DT compared to ST, and in the fatigued state compared to the non-fatigued state.
• Postural control progressively worsened with increasing fatigue levels during the treadmill protocol.
• The addition of an attentional task did not further impair balance performance when fatigued.

Conclusions:

• Both attentional demand and physical fatigue independently impair postural control.
• No synergistic (overadditive) effect was observed; fatigue-related decrements in postural control were similar under ST and DT conditions.
• Attentional resources appear sufficient to manage dual-tasking demands even under conditions of physical fatigue in young adults.