Applying high-density surface EMG to the study of neuromuscular disorders: a systematic review

Abstract

Objective: High-density surface electromyography (HD-sEMG) is a non-invasive and quantitative tool for studying neuromuscular disorders, enabling assessments of muscle excitation, motor unit (MU) characteristics and firing patterns. This systematic review reports the published evidence on the clinical applications of HD-sEMG across neuromuscular disorders, identifying the range of disorders studied, indexes utilized, and gaps in the literature. Methods: Systematic searches in PubMed and Scopus identified 200 studies, of which 55 met the inclusion criteria. The included articles were grouped into anterior horn cell disorders, muscle disorders and peripheral neuropathies. Results: Commonly studied muscles included the biceps brachii, tibialis anterior, vastus lateralis and the thenar muscles. In anterior horn cell disorders, HD-sEMG has studied fasciculation potentials, MU firing patterns and motor neuron excitability. For peripheral neuropathies, HD-sEMG revealed altered MU recruitment patterns and muscle fibre conduction velocity. In muscle disorders, HD-sEMG demonstrated disrupted MU propagation and reduced MU amplitudes. Conclusions: Our systematic review demonstrated that HD-sEMG is a promising tool in assessing neuromuscular disorders as it can effectively distinguish individuals with neuromuscular disorders from healthy subjects. Significance: However, the adoption of HD-sEMG in clinical practice is hindered by the lack of standardized protocols, complex data analysis and limited research on underexplored conditions.