David Burke

TL;DR: This chapter will review studies performed in human subjects demonstrating that a voluntary contraction can have profound effects on the excitability of the active axons and on their ability to transmit impulses.

TL;DR: Impalement of the nerve fibre by the microelectrode impairs the ability of the axon to conduct impulses across the site of injury, but impulse transmission can be secure even when the conduction time across individual internodes is prolonged to 500 μs.

TL;DR: It is concluded that subthreshold superexcitability in human motor axons is mainly due to the passive electrotonic effects of the stimulating current, but this is supplemented by an active component (about 12% of suprath threshold superezcitability), due to a local response of voltage‐dependent sodium channels.

TL;DR: The results suggest that there is a homogeneous group of motor units in ADM (with respect to contraction time) and that this group contains what are probable fast twitch fatigue sensitive and fatigue resistant motor units.

TL;DR: In ALS, there was significantly greater reduction of MUNE and CMAP amplitude recorded from plantar flexors when compared to dorsiflexors, suggesting preferential involvement of plantarflexor muscles, underpinning a ‘split leg’ appearance.