Author(s): SEYNAEVE, M., MANTINI, D., VANWANSEELE, B., DE BEUKELAAR, T.T., Institution: KU LEUVEN, Country: BELGIUM, Abstract-ID: 1397

INTRODUCTION:
In modern society insufficient sleep is increasingly prevalent, with one in three adults being chronically sleep-deprived. While the effect of this chronic sleep restriction (CSR) on cognitive functioning is well-established, the effects on motor control remain less clear. Some studies suggest a negative effect of insufficient sleep on tasks requiring higher sensorimotor control, such as balance tasks or submaximal contractions. However, we are still not able to pinpoint the exact underlying neural mechanisms behind this phenomenon. Therefore, this study aimed (i) to examine the effect of CSR on the ability to sustain submaximal plantarflexion (PF) and dorsiflexion (DF) contractions and (ii) to identify the underlying neural mechanisms using high-density electroencephalography (hdEEG) and electromyography (EMG).
METHODS:
Using actigraphy, we monitored the sleep pattern of healthy, young male participants for 15 consecutive nights. Motor control was evaluated after four different sleep periods: a baseline period consisting of three nights of habitual sleep (M1), a control period of four nights with normal sleep duration (M2), a period of CSR lasting four nights during which participants slept for only five hours per night (M3), and a recovery sleep period spanning three nights (M4). Motor control assessments consisted of a series of submaximal DF and PF contractions. More specifically, participants performed 6 DF and 6 PF contractions of one minute at 40% of the maximal voluntary contraction (MVC) and 1 submaximal DF and PF contraction until failure. During these contractions, brain activity was measured using hdEEG, and muscle activity of soleus, gastrocnemius, and tibialis anterior muscle using EMG. Complexity and variability of the torque and EMG signals, co-contraction ratios, time until failure, and power in different EEG bands were statistically analyzed using a repeated-measures ANOVA design.
RESULTS:
Data is currently being collected and analyzed. We hypothesize that participants ability to resist fatigue will be diminished after the period of CSR. Therefore, markers of fatigue will manifest earlier and to a larger extent. These fatigue markers include (i) a decrease in torque complexity based on detrended fluctuation analysis and entropy measures, (ii) an increase in torque variability, (iii) a decrease in median frequency of the EMG signal, (iv) increased muscle activity co-contraction ratios, (v) decreased time until failure and (vi) increase in EEG power bands. We anticipate that these markers will return to baseline levels following three nights of recovery sleep.
CONCLUSION:
A better understanding of the effect of CSR on motor control can offer important insights for clinicians, coaches, and athletes to improve performance, injury prevention programs, and overall health.