Role of dermatomes in the determination of therapeutic characteristics of channel acupoints: a similarity-based analysis of data compiled from literature

BACKGROUND: Analysis of the relationship between the nervous system anatomy and the therapeutic characteristics of all acupuncture points in the channel network may provide new insights on the physiological mechanisms underlying acupuncture stimulation for prevention, treatment, and rehabilitation purposes. This study investigates the association between the similarity of acupoints’ dermatomes, traditional actions, and contemporary indications. METHODS: Channel acupoints had their characteristics annotated from a literature review of four topographic atlases of Chinese medicine and one atlas of human anatomy: initials of the channel’s name (n = 14), sequential number in the channel (n = 67), acupoint’s name (n = 361), dermatomes related to perpendicular needle insertion (n = 31), traditional actions (n = 848), and contemporary indications (n = 1143). Jaccard’s similarity coefficient quantified the similarities between dual acupoints. All dual acupoints were evaluated to generate similarity matrices for each nominal variable. Cross-tables were generated by simultaneous classification of variables into levels of similarity with respect to: dermatomes versus traditional actions, dermatomes versus contemporary indications, and traditional actions versus contemporary indications. Goodman-Kruskal γ and Rousson γ*(2) were calculated based on cross-tables, bootstrap and permutated samples to evaluate the association and determination coefficient between variables, respectively. RESULTS: Significant associations were observed between levels of similarities of dermatomes and traditional actions (γ = 0.542; P < 0.001), dermatomes and contemporary indications (γ = 0.657; P < 0.001), and traditional actions and contemporary indications (γ = 0.716; P < 0.001). Similarities of dermatomes explained 16% of the variance of traditional actions and 25% of contemporary indications. Traditional actions explained 30% of the variance of contemporary indications. The association between traditional actions and contemporary indications was the highest one (γ = 0.716, 95% confidence interval (95% CI) = [0.715; 0.719]), followed by the association between dermatomes and contemporary indications (γ = 0.622, 95% CI = [0.621; 0.623]), and between dermatomes and traditional actions (γ = 0.446, 95% CI = [0.444; 0.447]), all with P < 0.001. CONCLUSIONS: The similarity of dermatomes between dual acupoints partially determined the similarity of traditional actions and contemporary indications, therefore dermatomes partially determine the therapeutic efficacy of acupuncture.