Different Surface Electromyography of Propagated Sensation along Meridians Produced by Acupuncturing Quchi Acupoint (LI11) or Control Points

This study investigated the propagated sensation along meridians (PSM) produced respectively by acupuncture at a specific acupoint of right-side Quchi (LI11), a nonacupoint on meridian (control meridian point), and neither meridian nor acupoint (control point). All the stimulated points were on the right brachioradialis along the large intestine meridian of hand Yangming. Surface electromyography (sEMG) was used to reflect the activity of the brachioradialis along the large intestine meridian of hand Yangming. The PSM rate of LI11 (59.21%) and the control meridian point (53.95%) were significantly higher than the control point (38.16%) (P < 0.05). After acupuncture, the brachioradialis sEMG amplitude was 5.08 ± 2.93 uV at LI11, 3.08 ± 1.18 uV at the control point, and 2.77 ± 1.36 uV at the control meridian point. The amplitude of LI11 was significantly higher than both the control meridian point and the control point (P < 0.05). When the sEMG activity of brachioradialis returned to the stable base line, brachioradialis sEMG duration at LI11 (265 ± 87.87 s) was significantly longer than that at the control meridian point (91.69 ± 42.98 s) and the control point (83.31 ± 32.76 s) (P < 0.05). In conclusion, acupuncture activated PSM at all points but showed an acupoint specificity at LI11 and a meridian specificity at the control meridian point.