The Cun Measurement System: An Investigation into Its Suitability in Current Practice

The Chinese anatomical inch (cun) measurement system is an essential component of traditional point location methods used in acupuncture. This study used the cun system to investigate any variation between the traditional measurements and the sample means for selected finger measurements, and for the forearm and lower leg lengths obtained from 50 volunteer subjects randomly selected from staff and students of the College of Traditional Chinese Medicine, University of Technology, Sydney. Subjects were seated while the finger and arm measurements were recorded, and were standing for leg measurement. Data were converted to ratios for analysis, with the one cun measurement for the thumb designated as the standard.

There were significant differences between the traditional measurements and the sample means for all hand and leg measurements in the sample. The results were generally the same for gender and the age groups studied. The authors conclude that the cun measurement system does not provide accurate estimates for contemporary Australian adults with respect to hand and lower leg measurements nor, to a lesser extent, with respect to measurements of the forearm. Consequently, it is recommended that methods of point location that are less reliant on the cun measurements (such as the proportional method) should be used in preference to the cundependent directional method.