Objective To investigate the effect of acupuncture in different tissue structures on deqi and the electromyography of acupoint area. Methods Twenty healthy subjects

respectively accepted 4 kinds of needling stimulation

i.e. stimulating skin at Zusanli(ST36)

stimulating ST36 with and without skin anesthesia using compound lidocaine cream

and stimulating at Dubi(ST35) without skin anesthesia. Deqi sensation of the acupuncturist and subjects were measured according to MGH Acupuncture Sensation Scale(MASS) during needling

and the myoelectricity around the acupoints was recorded simultaneously. The occurrence rate and intensity of the different deqi sensations

the relationship between the acupuncturist's and subjects' deqi sensations

and the integrated electromyogram(iEMG) were analyzed. Results Sharp pain and tingling were the main sensations during skin needling at ST36. Fullness

dull pain

soreness and acupuncturist's tightness were the main sensations during needling with or without skin anesthesia at ST36. Fullness was the main sensation during needling at ST35

while the intensity was lower than that during needling at ST36. A positive correlation in the intensity was found between subjects' fullness and acupuncturist's tightness during needling with or without skin anesthesia at ST36. The subjects' fullness appeared earlier about 5 seconds than acupuncturist's tightness. The iEMGs during subjects' fullness and acupuncturist's tightness were 2-3 times of that before needling. Conclusion Deqi sensations such as subjects' fullness

dull pain

soreness and acupuncturist's tightness are mainly related to the activity of the muscles under the acupoints. Subjects' fullness and acupuncturist's tightness always appear together. Acupuncturist's tightness may be mediated by the muscle stretch reflex induced by needling stimulation.