Effects of Cognitive Fatigue on Gait

Change in self-reported mental fatigue from baseline (PRE) to immediately after the mental fatigue induction task (POST), measured using the Visual Analog Scale for Fatigue (VAS). The VAS is a single-item, self-report scale ranging from 0 to 10, where 0 indicates "not tired at all" and 10 indicates "extremely tired." Higher scores indicate greater self-reported mental fatigue.

Change in mean reaction time on the Psychomotor Vigilance Task from PRE to POST TloadDback, used as a behavioral indicator of mental fatigue-related vigilance decrement. Slower reaction time in the POST, compared to PRE, means more mentally fatigued.

Change in gait velocity (meters/second), comparing baseline (PRE) walking trials to post-task (POST) walking trials, measured using inertial measurement units and pressure-sensing insoles. Here, there is no clear pattern; however, we expect participants to slow their gait spede after the fatigue intervention.

Change in gait cadence (steps/minute), comparing baseline (PRE) walking trials to post-task (POST) walking trials, measured using inertial measurement units and pressure-sensing insoles. There is no clear pattern here; however, we are expecting the cadence (steps/minute) to decrease after the fatigue intervention.

Change in stance phase duration and swing phase duration, each expressed as a percentage of the gait cycle, comparing baseline (PRE) walking trials to post-task (POST) walking trials, measured using inertial measurement units and pressure-sensing insoles. Stance phase refers to the portion of the gait cycle when the foot is in contact with the ground, while swing phase refers to the portion when the foot is off the ground and advancing forward. An increase in stance phase duration (with a corresponding decrease in swing phase duration) is generally associated with a more cautious, conservative gait pattern. A decrease in stance phase duration (with a corresponding increase in swing phase) may reflect a faster, less guarded walking pattern.

Change in peak hip, knee, and ankle joint angles (degrees) during walking, comparing baseline (PRE) walking trials to post-task (Post) walking trials, measured using inertial measurement units. Joint angles reflect the range of motion at each joint during the gait cycle. A reduction in joint angle range (i.e., smaller peak flexion/extension excursions) is commonly interpreted in the literature as a more restricted or cautious movement strategy, sometimes associated with reduced motor control.

Gait velocity (meters/second), measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how walking speed changes as participants rest and recover from mental fatigue. Values will be reported separately for each timepoint. We will be expecting the gait velocity to increase after resting.

Gait cadence (steps/minute), measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how stepping rate changes as participants rest and recover from mental fatigue. Values will be reported separately for each time point.

Stance phase duration and swing phase duration, each expressed as a percentage of the gait cycle, measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how the distribution of gait phases changes as participants rest and recover from mental fatigue. Values will be reported separately for stance and swing phase at each timepoint. Stance phase is the gait phase where the foot is on the ground, while swing phase is the gait phase where the foot is moving forward (off the ground).

Peak hip, knee, and ankle joint angles (degrees) during walking, measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how the joint range of motion changes as participants rest and recover from mental fatigue. Values will be reported separately for hip, knee, and ankle at each time point.

Self-reported mental fatigue, measured using the Visual Analog Scale for Fatigue (VAS), at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how perceived fatigue changes as participants rest and recover. The VAS ranges from 0 to 10, where 0 indicates "not tired at all" and 10 indicates "extremely tired"; higher scores indicate greater fatigue. Values will be reported separately for each time point.

Change in relative electroencephalography (EEG) spectral power (%) in theta and alpha frequency bands, recorded during the TloadDback task, providing physiological confirmation of mental fatigue induction. Increases in theta and alpha power, particularly over central and posterior regions, are commonly reported in the literature as indicators of cognitive fatigue accumulation. Values will be reported separately for each frequency band.

Change in pupil diameter (millimeters), recorded during the TloadDback task using eye-tracking, providing physiological confirmation of mental fatigue induction. A decrease in pupil diameter over the course of the task is commonly reported in the literature as an indicator of increasing mental fatigue.

Change in blink rate (blinks per minute), recorded during the TloadDback task using eye-tracking, providing physiological confirmation of mental fatigue induction. An increase in blink rate over the course of the task is commonly reported in the literature as an indicator of increasing mental fatigue.