Observer-Blind Randomized Crossover Trial of Yamamoto New Scalp Acupuncture in Diagnosis and Treatment Points for Neck Pain and Shoulder Stiffness in Healthy Participants.

Background: Yamamoto New Scalp Acupuncture (YNSA) uses microsystems in the body for various treatments. In YNSA diagnosis, Hoku is important for determining the treatment side. The A-point is used for treating neck and shoulder symptoms, and the D-point for low back pain; however, no studies support this. Aim: To investigate the site specificity of stimulation at the A-point and the usefulness of Hoku diagnosis. Methods: Nineteen healthy adults with no previous acupuncture experience were included. Participants randomly received three sessions of A-point, D-point, or no stimulation, followed by a 1-week minimum washout period. The visual analog scale (VAS) of shoulder stiffness, pressure pain threshold (PPT), and muscle hardness were evaluated at the bilateral shoulder region before, during, and 20 min after the stimulation, with the observer blinded to group allocation. Results: No significant differences were found in PPT between the three groups. Significant differences in VAS were observed between the three groups and in the comparison between the A-point and the control group. Intragroup analysis showed a significant improvement in the A-point and none in the D-point group. In subjects who had tenderness and induration on the right side of Hoku, the VAS score was significantly improved between the groups and multiple comparisons between the A-point and the control. The effect size was greater when limited by the Hoku diagnosis. Conclusion: The stimulation point selected according to the diagnosis point information might be more effective in YNSA. However, the results of this study were based on healthy adults, so the effect size was small. In the future, large-scale studies on patients with symptoms are needed.