Table 1 Treatment details for each group

Jin acupuncture

I. Stress concentration points

a. In the midpoint of the connection between BL9 and BL10

b. In the midpoint of the connection between GB20 and SJ17

II. Positive reaction points

c. GB8

d. In the midpoint of temporomandibular joint

III. Nerve stimulation points

e. The sensitive point of occipital protuberance of upper line of posterior occipital region

f. Sensitive points on the posterior border of the upper third of the sternocleidomastoid muscle

g. Sensitive spots in intertubercular sulcus of the second transverse process

a, b, f, g and GB34: Perpendicular insertion with 1.2 cun

c: Oblique insertion with 0.8 cun toward the ipsilateral body

d, e: Oblique insertion with 0.5 cun down

Retaining needles for 25 min Lifting-thrusting, twirling, and rotating for de qi sensation

Matching point: GB34

Pseudo acupuncture

5 cm away from a, b, c, d, e, f, and g; 8 points in total

Retaining needles for 25 min only, pricking skin with no manipulation to avoid de qi sensation