Effects of Electrical Stimulation Applied to Paraspinal Tissues on Peripheral Blood Circulation.

To investigate effects of electrical stimulation on the peripheral blood circulation being remote from the stimulated site, human paraspinal tissues were stimulated, and finger skin temperature, acceleration plethymogram (APG) in finger, and finger blood flow (estimate by vein width) were examined. With some appropriate electrical stimuli (1Hz strong, 3Hz strong, 5Hz soft) at the paraspinal tissues of 7^ cervical vertebral level, skin temperature, the value of APG b/a (blood vessel distensibility) and APG amplitude (magnitude of acceleration plethysmogram) in finger significantly rose, and with 3Hz strong stimuli, finger vein width significantly increased, but any effect was not found with 10Hz soft or 30Hz soft stimuli. The thermograph imaging showed that the skin temperature of hand and ulnar forearm rose during the stimuli at 7^ cervical vertebral level, but not at 3^<rd> thoracic vertebral level. These findings suggest that through somato-sympathetic reflex, appropriate electrical stimuli to the paraspinal tissues improved peripheral blood circulation of the same dermatome region being remote from the stimulated site. Besides, even with stimuli conditions that none of the subject experienced any pain or discomfort, electrical stimuli could improve the local peripheral blood circulation being remote from the stimulated site. The similar methods to the electrical stimuli examined in the present study might be useful as a clinical measure, especially at the acute stages of clinical cases in which the direct approaches to injury site are difficult due to a pain with inflammation or insertion of cast brace.