UNASSIGNED: The massed action potential (M-wave) elicited through nerve stimulation underpins a wide range of physiological and mechanical understanding of skeletal muscle structure and function. Although systematic approaches have evaluated the effect of different factors on the M-waves, the effect of the location and distribution of activated fibres within the muscle remains unknown. By detecting M-waves from the @entity10036 ( @entity10036 ) of twelve @entity1 with a grid of 128 electrodes, we investigate whether different populations of muscle units have different spatial organisation within @entity10036 . If populations of muscle units occupy discrete @entity10036 regions, current pulses of progressively greater intensities applied to the @entity10036 nerve branch would be expected to lead to local changes in M-wave amplitudes. Electrical pulses were therefore delivered at 2pps, with the current pulse amplitude increased every 10 stimuli to elicit different degrees of muscle activation. The localisation of @entity10036 response to increases in current intensity was determined from the spatial distribution of M-wave amplitude. Key results revealed that increases in M-wave amplitude were detected somewhat locally, by 10%-50% of the 128 electrodes. Most importantly, the electrodes detecting greatest increases in M-wave amplitude were localised at different regions in the grid, with a tendency for greater stimulation intensities to elicit M-waves in the more distal @entity10036 region. The presented results indicate that M-waves recorded locally may not provide a representative @entity10036 response, with major implications for the estimation of e.g. the maximal stimulation levels, the number of motor units and the onset and normalisation in H-reflex studies.

Spatial Variation of Compound Muscle Action Potentials across XXXX Gastrocnemius medialis.

@entity1 :: ('9606', 'Species') :: ['participants'] @entity10036 :: ('MESH:D020423', 'Disease') :: ['medial gastrocnemius', 'MG']
@entity1 :: (9606,Species) :: ['Human']
