Brief posturographic test as an indicator of fatigue

Abstract

The purpose of the present paper was to analyze the efficiency of an abbreviated, albeit objective posturographic test as an indicator of fatigue. Posturography was measured in 10 healthy adults (age 18-33 years, male/female 7/3). Baseline posturographic measurements were taken for each subject. Later, a shorter (3-min) posturographic test was administered 12 times during 25 h of sleep deprivation. This was correlated with subjective assessment of fatigue using a questionnaire and cognitive performance assessed with a reaction time test (Psychomotor Vigilance Test). Although showing significant individual differences, the score of the abbreviated posturographic examination, normalized to each subject's baseline performance ('fatigue index') had a pronounced circadian pattern with a peak of instability in the early morning hours. Fatigue index was highly correlated with the cognitive test ( r = 0.80-0.90). A substantial, albeit weaker correlation was found between the fatigue index and the subjective fatigue scores ( r = 0.59-0.75). Fourier spectral analysis showed that low median sway (0.10-0.50 Hz), considered to be an expression of vestibular control, was most affected by fatigue. The study demonstrates that cognitive deterioration caused by fatigue can be objectively predicted by an abbreviated postural test of ≤ 3 min. This test is promising to be valid, reliable, and practicable, while being significantly correlated with physiological markers and validated cognitive measures of fatigue obtained by substantially more time-consuming and less convenient methods.

Deranged Dimensionality of Vestibular Re-Weighting in Multiple Chemical Sensitivity

“…Furthermore, increased body sways within the middle interval and in classical posturography parameters especially during closed eye condition tend to confirm similar findings in previous studies, and result in a decreased ability to adapt to balance perturbations under complex conditions in certain disorders affected by a lack of vigilance [45][46][47][48][49]. It has previously been noted that the integration of information from the visual, vestibular and somatosensory receptors and motor coordination are processes requiring attention and vigilance [48], especially when information from other sensory systems is not reliable [50].…”

Quantifying time awake posturographically

“…The pattern is consistent with that of the circadian sleepiness: balance correlates with physiologic- [66], manifest- [65], and perceived [64][65][66] sleepiness. These studies have recorded balance during at least 19 h of sustained wakefulness, and suggest that sleepiness impairs balance [46,[64][65][66][67][68]. Studies that have recorded balance during 8 h work shifts support this finding, by reporting that work stress and fatigue impair balance [8,69].…”

“…Balance exhibits a circadian rhythm: it has a nadir at night (6-7 am), and in the afternoon (1-4 pm) [46,65]. The pattern is consistent with that of the circadian sleepiness: balance correlates with physiologic- [66], manifest- [65], and perceived [64][65][66] sleepiness.…”

“…The reason is that static posturography can detect balance changes related to circadian variations [33,46,[64][65][66][67]69] and should therefore be able to detect homeostatic changes. Moreover, static posturography is a clinical and commercialized technique -i.e.…”

Effects of Sleep Deprivation on Human Postural Control, Subjective Fatigue Assessment and Psychomotor Performance

“…balance correlates with physiological, manifested and perceived sleepiness. 3,9,14 Disruption to circadian rhythms can upset physiological factors, such as motor activity, body temperature, sleep, wakefulness, hormonal secretions, blood pressure, and work performance and should, therefore, be an important consideration in the study of postural sway and the measurement of fatigue. 25 To avoid any confounding effects of circadian rhythm in the present study, postural sway, subjective fatigue assessment and psychomotor performance were measured at the same time before and after 24 h of sustained wakefulness.…”