Antagonist Muscle Prefatigue Increases the Intracortical Communication between Contralateral Motor Cortices during Elbow Extension Contraction

Abstract

To investigate the cortico-cortical coupling changes related to antagonist muscle prefatigue, we recorded EEG at FC3, C3, FC4, and C4 electrodes of twelve young male volunteers during a 30-second-long, nonfatiguing isometric elbow extension contraction with a target force level of 20% MVC before and after a sustained fatiguing elbow flexion contraction until task failure. EEG-EEG phase synchronization indices in alpha and beta frequency bands were calculated for the pre- and postfatigue elbow extension contractions. The phase synchronization index in the beta frequency band was found significantly increased between EEG of FC3-C3. The increased phase synchronization index may reflect an enhanced intracortical communication or integration of the signals between contralateral motor cortices with antagonist muscle prefatigue, which may be related to the central modulation so as to compensate for the antagonist muscle prefatigue-induced joint instability.

A Comparative Study of EMG Indices in Muscle Fatigue Evaluation Based on Grey Relational Analysis during All-Out Cycling Exercise

“…Muscle fatigue represents a complex phenomenon and encompasses a number of changes occurring at both central and peripheral level [ 35 – 38 ]. Although central and peripheral mechanisms are highly interactive, the contribution of two mechanisms may be quite different in certain conditions.…”

Resistance-induced brain activity changes during cycle ergometer exercises

“…EEG synchronization increases as the mental state of drivers shifts from alertness to fatigue [ 18 , 19 ], and shed light on the reorganization of cortico-cortical couplings during mental fatigue [ 20 , 21 ] or driving fatigue [ 22 ]. Increased cortico-cortical coupling has also been observed during the fatigue periods of elbow extension contraction [ 23 ] and cycling exercise [ 24 ]. In addition, brain network connectivity was modulated during an endurance cycling exercise [ 25 ].…”

“…In addition, brain network connectivity was modulated during an endurance cycling exercise [ 25 ]. The aforementioned exercise-induced change in cortico-cortical coupling or network connectivity is demonstrated during the sustained constant-intensity exercise [ 23 ] or the incremental graded-intensity exercise [ 24 , 25 ] which may derive from the demands that exercise and motor work make on cognitive processing.…”

“…In literatures, EEG coherence and phase synchronization as well as EEG power in alpha and beta bands are mostly used to study brain connectivity [ 23 – 25 ] and brain activation [ 10 , 15 ] during exercise. The beta rhythm is regarded as an important role in motor control, whereas the modulation of alpha rhythm is associated with different stages of exercise [ 26 ].…”

Muscle Fatigue Enhance Beta Band EMG-EMG Coupling of Antagonistic Muscles in Patients With Post-stroke Spasticity

“…Neuromuscular fatigue has the tendency to arise when performing physical activities after stroke, which has received little attention in clinical rehabilitation research ( Boudarham et al, 2014 ). It can be defined as a reversible reduction in the neuromuscular system’s capacity to generate force or power ( Vollestad, 1997 ), which encompasses a number of changes occurring at both the central and peripheral levels ( Enoka et al, 2011 ; Wang et al, 2017 ). The relationship between agonist and antagonist muscles during muscle fatigue has been focused on, and significant muscle fatigue-induced interaction changes have been reported previously ( Duchateau and Baudry, 2014 ; Arellano et al, 2016 ).…”