Effect of transcutaneous electrical nerve stimulation on the pressor response to static handgrip exercise.
OBJECTIVE
A proposed mechanism for the pain-relieving properties of transcutaneous electrical nerve stimulation (TENS) is gating of impulses carried by group III and IV afferent nerve fibers. The purpose of this study was to determine the effects of TENS on the pressor response to static exercise, a response mediated by group III and IV muscle afferents.


METHODS
Sixteen subjects (9 men, 7 women) with no known history of cardiovascular, neurologic, or musculoskeletal disease participated.


METHODS
We measured arterial pressure, heart rate, and sympathetic activity during sustained, 25% maximal handgrip exercise. Each subject performed the handgrip exercise with and without conventional TENS applied to the ipsilateral forearm and, in a separate trial, to the contralateral leg.


RESULTS
The sympathetically mediated pressor response to handgrip exercise was blunted when TENS was applied to the ipsilateral forearm, but not when TENS was applied to the contralateral leg.


CONCLUSIONS
These data support the concept that central transmission of neural impulses traveling in group III and IV fibers can be modulated by other afferent inputs converging on the same spinal level.
Hollman
J E
JE
University of Wisconsin Hospital and Clinics, Madison 53792, USA.
Morgan
B J
BJ
D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D005542:Forearm / Q000294:innervation; D018737:Hand Strength / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D007866:Leg / Q000294:innervation; D008297:Male; D008875:Middle Aged; D009475:Neurons, Afferent / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology; D004561:Transcutaneous Electric Nerve Stimulation