Computed extracellular potentials of a number of muscle fibres. II. Communication. Effect of axial displacement of the muscle fibres
Dimitrov, G.V.
Electromyography and Clinical Neurophysiology 18(6): 517-526
1978
ISSN/ISBN: 0301-150X PMID: 743937 Document Number: 126863
A mathematical model is used to study the effect of axial displacement of the muscle fibers, respectively, of the motor endplates, the fiber ends and the depolarized zone, which is characteristic of muscles with inclined fibers, on the shape and magnitude of the extracellular potentials generated by them. The changes in the shape of the summated extracellular potentials, due to axial displacement, are the smallest behind the fiber ends; axial displacement has a slight effect on the terminal phases and a more significant one on the negative phase. Upon increasing the distance to the activated fiber, the effect of the axial displacement of the fibers, respectively, the motor endplates on the amplitude of the negative phase of the potential, recorded above the motor endplates decreases, and in some cases may be insignificant; axial displacement of the motor endplates enhances the negative phase duration mainly at the expense of the raising phase and decreases the negative phase amplitude decline, at not significantly great radial distances.