Dynamics of brain-muscle interaction with neuromuscular fatigability: systematic review.

Introduction: Neuromuscular fatigability impairs motor performance in both healthy and neurological populations. Corticomuscular coherence (CMC), derived from EEG and EMG recordings, reflects the brain-muscle interaction during movement. However, the impact of neuromuscular fatigability on CMC in healthy and neurological populations remains unclear. Methods: A systematic search of PubMed, Web of Science, and Embase was conducted up to 02/02/2026. Eligible studies investigated CMC changes related to fatiguing tasks in healthy or neurological participants. Two reviewers independently screened, extracted data, and assessed the risk of bias. Results: Fifteen non-randomized experimental studies were included, comprising predominantly neurologically healthy adults (n= 174) and a limited number of individuals with neurological conditions (n= 14). Fatiguing tasks varied widely in muscle group, contraction type, mode, and intensity. Across studies, neuromuscular fatigability was associated with heterogeneous changes in CMC, most commonly involving reductions in beta band coherence as fatigue progressed. However, preserved or increased beta band CMC was also reported in both upper- and lower-limb tasks, particularly during sustained or low- to moderate-intensity contractions. Alpha and gamma band CMC were less reported across the included studies. No consistent or limb-specific pattern of CMC modulation emerged, with observed responses depending on task demands, contraction intensity, muscle group, and stage of fatigue. Evidence from neurological populations was sparse but suggested generally lower CMC magnitude and greater disruption during fatiguing tasks compared with healthy controls. Discussion: These findings indicate that fatigue-related changes in CMC do not reflect a uniform loss of corticomuscular coupling but rather task- and context-dependent adaptations in brain-muscle communication. Reductions in CMC may reflect diminished efficacy of corticospinal synchronization, whereas preserved or increased coherence may represent stabilization to maintain motor output with fatigue. By synthesizing how neuromuscular fatigability reshapes CMC across different experimental contexts and highlighting key methodological limitations, this review provides a framework to inform the design of future rehabilitation or neuromodulation trials targeting fatigability in both healthy and neurological populations.