Evaluation of the cun measurement system of acupuncture point location.

Locating acupuncture points reliably and reproducibly is indispensable for the scientific research of acupuncture and for assuring the best care of patients. Unreliable point location can produce confounding results for acupuncture research and clinical practice. Two traditional methods of point location are currently used, directional (F-cun) and proportional (B-cun) methods, which are collectively called the cun measurement system. Reports have been published on the validity of the cun measurement system in Australian subjects; however, as acupuncture originated in ancient East China, it is possible that anthropometric data may differ in Asian people and other races. Therefore, we measured anthropometric data according to the cun measurement system in contemporary Korean patients. The F-cun measurements were significantly different from the B-cun measurements and varied significantly according to the arbitrarily selected F-cun standard. In addition, we observed further differences of F-cun measurements in the extremities of obese subjects. We concluded that the F-cun method is unreliable and that further research should be conducted to determine a more accurate point-locating method primarily based on the B-cun method.