Is Acupoints Sensation Necessary for Acu-TENS to Elicit Physiological Changes in Healthy Subjects?

Traditional Chinese Medicine (TCM) practitioners believe that health can be maintained if the body has a balanced ying-yang or the qi flows in correct strength and quality along the meridians.Stimulation of the acupoints such as by acupuncture can awaken and modulate qi in the channels and is able to regulate and restore yin-yang balance.However, there are some drawbacks associated with acupuncture which may limit its applications. These include transmission of infectious disease, pneumothorax and other problems associated with organ punctures, cardiac tamponade, and broken needles with remnants migrating to other locations.Studies have shown that when TENS is applied over acupoints (Acu-TENS), it is effective in reducing dyspnoea in patients with chronic obstructive pulmonary disease,facilitate early haemodynamic recovery after open-heart surgery,relieve labor pain,increase in blood β-endorphin level,reduce blood pressure changes in normal healthy subjects and decrease airway resistance.Despite these promising results, how Acu-TENS works still remain unclear.This study aimed to investigate the effects of Acu-TENS over Hegu (LI4) and Quichi (LI4) on the autonomic nervous system activities and to investigate whether the subject could experience distinct sensation as deqi.