Psychophysical ratings. A: The averaged index of subjective pain experienced by all participants (n = 18); only five sensations were listed with mean scale above zero (meaning that at least one subject experienced this sensation). Significant difference of verum acupuncture stimulation compared to the sham stimulation condition was observed in soreness, fullness and sharp pain level. Error bars were based on 95% Confidence Interval. B: The frequency of the sensations occurred among all the subjects. Error bars were based on 95% Confidence Interval. Although the sensations such as soreness, numbness and fullness occurred at higher rates among the subjects under acupuncture intervention as compared to sham stimulation, no significant difference in the overall frequency of experience was found between acupuncture and sham conditions using Fisher's test (P > 0.05).