Oscillations in motor unit discharge are reflected in the low-frequency component of rectified surface EMG and the rate of change in force.

摘要: Common drive to a motor unit (MU) pool manifests as low-frequency oscillations in MU discharge rate, producing fluctuations muscle force. The aim of the study was examine temporal correlation between instantaneous rate and rectified EMG low frequencies. Additionally, we attempted whether there is first derivative force (dF/dt). Healthy young subjects produced steady submaximal with their right finger single task or while maintaining pinch-grip left hand dual task. Surface fine-wire potentials were recorded from dorsal interosseous hand. band-pass filtered (5–1,000 Hz) full-wave rectified. Rectified surface MUs smoothed by Hann-window 400 ms duration (equivalent 2 Hz low-pass filtering). In each identified MUs, positively correlated rectified-and-smoothed confirmed distinct peak cross-correlation function greater values compared temporally dF/dt more than EMG. results indicated that component provide information on rate.