Electrodes’ Configuration Influences the Agreement Between Surface EMG and B-Mode Ultrasound Detection of Motor Unit Fasciculation

Muscle fasciculations, resulting from the spontaneous activation of motor neurons, may be associated with neurological disorders, and are often assessed intramuscular electromyography (EMG). Recently, however, both ultrasound (US) imaging multichannel surface EMG have been shown to more sensitive fasciculations. In this study we combined these two techniques compare their detection sensitivity fasciculations occurring in different muscle regions investigate effect electrodes' configuration on agreement. Monopolar EMGs were collected medial gastrocnemius soleus an array 32 electrodes (10 mm Inter-Electrode Distance, IED) simultaneously b-mode US images detected alongside either proximal, central or distal groups. Fasciculation potentials (FP) identified single differential 10 (SD1), 20 (SD2) 30 (SD3) IEDs, fasciculation events (FE) image sequences. The number, location, size FEs FPs healthy participants analyzed. Overall, showed similar sensitivities was equally FE proximal calf regions, while number FP revealed by increased significantly IED larger distally, where depth decreased. agreement between relatively low, a percentage classified as common ranging 22% for smallest 68% largest IED. relevant uniquely is discussed terms spatial US, which suggest that combination US-EMG likely maximise