Eighty healthy volunteers were evaluated; 40 women and 40 men divided into two equal groups of young and elderly subjects. Half of the individuals in each group were stimulated with 5 and 50Hz frequency, with pulse duration of 20, 100, 400, 1000 and 3000µs applied on the flexor muscle bellies of the wrist and fingers. The threshold of sensory perception was identified as the first sensation of increased current intensity and the threshold of motor response as the minimum muscle contraction detected.

Eighty healthy volunteers were evaluated; 40 women and 40 men divided into two equal groups of young and elderly subjects. Half of the individuals in each group were stimulated with 5 and 50Hz frequency, with pulse duration of 20, 100, 400, 1000 and 3000µs applied on the flexor muscle bellies of the wrist and fingers. The threshold of motor response as the minimum muscle contraction detected.

A pulse generator was used for data collection, with constant current intensity, and the following parameters were used for current stimulation: square biphasic wave, and pulse-width varying in 20, 50, 100, 200,300, 500, 1000 and 3000µs, at a frequency of 5 or 50Hz. During the procedure, the volunteers remained seated, with the forearm in supination, resting on a table. The tests always initiated with 20µs pulse-width, with high intensity until the threshold of sensory perception were reached. At this point, the intensity was reset and the procedure began again, followed by the next pulse duration, progressively evolving up to 3000µs and repeated three times with a 10-minute interval between the tests. The procedures were carried out with a 72 hour minimum interval for different frequencies.

A pulse generator was used for data collection, with constant current intensity, and the following parameters were used for current stimulation: square biphasic wave, and pulse-width varying in 20, 50, 100, 200,300, 500, 1000 and 3000µs, at a frequency of 5 or 50Hz. During the procedure, the volunteers remained seated, with the forearm in supination, resting on a table. The tests always initiated with 20µs pulse-width, with high intensity until the threshold of motor response were reached. At this point, the intensity was reset and the procedure began again, followed by the next pulse duration, progressively evolving up to 3000µs and repeated three times with a 10-minute interval between the tests. The procedures were carried out with a 72 hour minimum interval for different frequencies.