Test--retest reliability of a modified multiple point stimulation technique for motor unit number estimation.

Objective: Multiple point stimulation (MPS) is a widely used technique to estimate the number of motor units in a muscle. Test-retest reliability must be high for the motor unit number estimates to be clinically useful. We hypothesized that the reliability of MPS can be improved by using a long stimulus pulse width (1ms), in addition to the standard 0.

Transcranial direct current stimulation of the primary motor cortex affects cortical drive to human musculature as assessed by intermuscular coherence.

Intermuscular coherence analysis can be used to assess the common drive to muscles. Coherence in the beta-frequency band (15-35 Hz) is thought to arise from common cortical sources. Intermuscular coherence analysis is a potentially attractive tool for the investigation of motor cortical excitability changes because it is non-invasive and can be done relatively quickly.