39, 41 We may assume that the effect of EA on spasticity may also be related to the stimulation at the motor point of the affected muscle.
The motor point of the muscle were found by means of electrical stimulation and that point, with the lowest stimulation threshold providing the highest muscle contraction, visually registered, was chosen for the stimulation protocol.
The amplitude of a 30 Hz stimulation train administered at the TA motor point was varied sinusoidally, thus changing the number of the recruited motor units, and hence the tension at the tendon, in the same fashion.
The electrical neuromuscular stimulation, it is the application of electrical stimulation of sufficient intensity to produce a visible muscle contraction which is applied to the motor point of the muscle, in order to promote muscle strengthening.
The motor point was defined as the location that corresponded to the lowest possible threshold current, and the motor threshold current was defined as the lowest train stimulation current that resulted in visible muscle contraction.
The ability to induce interpolated twitches, by surface stimulation over muscle motor points, requires intact function of terminal efferents, neuromuscular junctions, and muscle membranes.
After a rest period of 10 min, peripheral and central fatigue will be measured during a 2 min sustained MVC of the biceps brachii muscle.[ 18] During these 2 min, electrical endplate stimulation over the motor points of the medial and lateral head of the biceps brachii muscle will be applied every 15 s, leading to superimposed force responses.
In this study the locations of the motor points were confirmed using peripheral nerve electrical stimulation (PNS) (SY-708A, Tianrui, China).
The basis of this is that, if a muscle is being submaximally activated voluntarily, further activation is possible by superimposing electrical stimulation via surface electrodes applied over the motor nerve or over the muscle motor points.
In regard to point (1), laser pain was not significantly modified by motor cortex stimulation in normal subjects or migraine patients, despite a significant reduction of the evoked responses recorded from the vertex.
