Je. Hollman et Bj. Morgan, EFFECT OF TRANSCUTANEOUS ELECTRICAL NERVE-STIMULATION ON THE PRESSOR-RESPONSE TO STATIC HANDGRIP EXERCISE, Physical therapy, 77(1), 1997, pp. 28-36
Background and Purpose. A proposed mechanism for the pain-relieving pr
operties of transcutaneous electrical nerve stimulation (TENS) is gati
ng 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 pres
ser response to static exercise, a response mediated by group III and
IV muscle afferents. Subjects. Sixteen subjects (9 men, 7 women) with
no known history of cardiovascular, neurologic, or musculoskeletal dis
ease participated. Methods. Mie measured arterial pressure, heart rate
, and sympathetic activity during sustained, 25% maximal handgrip exer
cise. Each subject performed the handgrip exercise with and without co
nventional TENS applied to the ipsilateral forearm and, in a separate
trial, to the contralateral leg. Results. The sympathetically mediated
presser response to handgrip exercise was blunted when TENS was appli
ed to che ipsilateral forearm, but not when TENS was applied to the co
ntralateral leg. Conclusion and Discussion. These data support the con
cept that central transmission of neural impulses traveling in group I
II and IV fibers can be modulated by other afferent inputs converging
on the same spinal level.