Estimation of impulse response between electromyogram signals for use in conduction delay distribution estimation.

The time delay between two surface electromyograms (EMGs) acquired along the conduction path is used to estimate mean action potential conduction velocity. Modeling the linear impulse response between "upstream" and "downstream" EMG signals permits an estimate of the distribution of velocities, providing more information. In this work, we analyzed EMG from bipolar electrodes placed on the tibialis anterior of 36 subjects, using an inter-electrode distance of 10 mm.

Modeling the impulse response between pairs of EMG signals to estimate conduction delay distribution.

Mean electromyogram (EMG) conduction delay is often estimated as the average time delay between two surface EMG recordings arranged along the conduction path. It has previously been shown that the complete distribution of conduction delays can be estimated from the impulse response relating the "upstream" EMG recording to the "downstream" recording. In this work, we examined regularized least squares methods for estimating the impulse response, namely the pseudo-inverse with small singular values discarded and post hoc lowpass filtering.

Reliability of a simple method for determining muscle fiber conduction velocity.

Introduction: This study evaluated the reliability of muscle fiber conduction velocity (MFCV) measurement.

Methods: Forty healthy, young participants performed isometric dorsiflexion of the foot on 3 non-consecutive days. The reliability of force, root-mean-square (RMS) amplitude of the surface electromyographic (sEMG) signal, and MFCV were evaluated using the intraclass correlational analysis of variance technique.