Muscle activity was bilaterally tested with needle electromyography at rest status, targeting at myofascial trigger points (MTrPs) in the frontal, temporal, sternocleidomastoid (SCM), splenius capitis, splenius cervicis and trapezius of each subject.

It was evaluated with EMG/EP equipment(9031A070 KEYPOINT Dantec) and the matching disposable needle electrode(Specification: 25mm*0.3mm, 30G) with a sampling frequency of 125 Hz and a measuring range of 0.2mv.The spontaneous electric activity of each pericranial muscle was recorded as 0 to 4 scores: 0 score= no repeatable spontaneous electric activity, 1 score=a single, repeatable string of spontaneous electric activity, 2 scores= obvious spontaneous electric activity in two or more areas of the muscle, 3 scores= obvious spontaneous electric activity in any area of the muscle, 4 scores= a lot of spontaneous electric activity over the whole record screen. The maximum scores of a participant was 48(6*2*4［insertion(frontal, temporal, sternocleidomastoid, splenius capitis, splenius cervicis and trapezius) *right or left* maximum scores of a muscle]).

This scale included three parts:Pain Rating Index (PRI), a 10cm-visual analogue scale(VAS) and Present Pain Intensity (PPI).PRI included 15 items to describe the characteristics of the pain(like nature and emotional problems) and each item was assessed with 0-3 scores.The higher scores respresented more serious condition.Total points of PRI was 0-15*3.VAS relefected their average intensity of the headache during the last month and was recorded as 0-10 scores according to the length.The higher scores respresented more serious average pain;PPI was recorded as 0-5 scores and the higher scores respresented more serious present pain(0 point=no pain;1 point=a little uncomfortable;2 points=uncomfortable;3 points=obvious headache;4 points=serious headache;5 points=unbearable headache).Total scores of SF-MPQ= PRI +VAS +PPI.