Studies of needling depth in acupuncture treatment

To investigate safety and De-qi (obtaining of needling sensation) depth of acupoint and their relation to therapeutic effect, and to electric resistance.

1) We plotted the graph to compare the differences of each acupoint depth between modern and ancient acupuncture writings; 2) 80 cadavers, and 240 subjects with computer tomography of chest to study the safety depth of acupoint were used, and their correlation to the length of the second phalanx of middle finger as Tong Shen Cun's standard; 3) 300 subjects were divided according to their body height and weight into normal-weight, over-weight and under-weight groups of 100 subjects to study the De-qi depth of acupoint; 4) using the 120 subjects which accepted acupuncture treatment due to pain symptom to study the relation between De-qi depth and therapeutic effect; 5) 107 subjects of different sizes were used to study the relation between De-qi depth and thickness of body, and electric resistance.

Acupoint depth was greater in modern acupuncture writings than in ancient writings. The safety depth of each acupoint in chest and in back was different, and they had high correlation to Tong Shen Cun's standard in adults, but not in newborns. The safety depths in chest acupoints were greater in female than in male, but not in back, and they related to body size. The De-qi depth was correlated with their therapeutic effects, corresponding to body thickness, but not related to their electric resistance.

Safety and De-qi depth of acupoint are related to body thickness. The length of the second phalanx of middle finger may be used as Tong Shen Cun's standard in adults, but not in newborns.