Retrospective study using MRI to measure depths of acupuncture points in neck and shoulder region

Objectives: There are safety issues associated with acupuncture treatment. Previous studies regarding needling depth of acupuncture points revealed inconsistent results due to vague depth definition, acupuncture point localisation and measuring tools. The objective of this study is to find and compare the differences of the mean depths of 11 acupuncture points in the neck and shoulder region between subjects, with variables including gender and body mass index (BMI). Setting: This study was conducted at a single medical center in Taiwan. Participants: Three hundred and ninety-four participants were included in this study. Participants were grouped according to gender and BMI. Acupuncture points were localised by WHO standard and measured by MRI. Outcome measures: The distance from the needle insertion point (surface of the skin) to any tissues that would cause possible/severe complications. Results: Mean depths of 11 points were obtained in groups of different BMI and gender. Mean depths of all participants regardless of BMI and gender are as follows, in centimetres: GB21=5.6, SI14=5.2, SI15=8.8, GV15=4.9, GV16=4.6, GB20=5.0, ST9=1.6, SI16=1.8, SI17=2.4, TE16=3.1, LI18=1.3. Participants with higher BMI had greater measured depths in both gender groups. Male participants had larger mean depths than female participants regardless of BMI except in SI17 and LI18. When taking BMI into consideration, depths in male participants are greater than in female participants in most of the points except the following: GB21, TE16 in obesity group; ST9 in underweight and obesity group; SI16 in ideal body weight, overweight and obesity group; SI17, LI18 in each group. Conclusions: Participants with higher BMI had greater measured depths and males tended to have greater depths in most of the points. Clinical practitioners are recommended to consider this information to prevent complications when applying acupuncture treatment to their patients.