Hi guys, I have an extremely elementary question about the 'cun measurement'. I have an interest in acupressure and would like to locate acupuncture points on my body.
Now, I've tried to measure the cun standard with a ruler in centimeters. Here are the results:
1 cun (using the width of the distal inter-phalangeal joint of the thumb)= 2 cm
1 cun (using the distance between the distal and proximal inter-phalangeal joints of the middle finger) = 2 cm
1.5 cun (width of index and middle fingers, at the proximal inter-phalangeal joints) = 4 cm
2 cun (The distance from index finger's tip and the proximal interphalangeal joint) = 4.4 cm
2 cun (combined breadth of the index, middle and ring finger, at the level of the index finger`s end/tip) = 4.7 cm
3 cun (combined breadth of the 4 fingers held together, dorsal aspect, excluding thumb, at level of proximal interphalangeal joint of middle finger) = 7 cm
The results show that the cun and ruler measurements do not scale linearly. I am aware that there may be errors in my ruler measurement. However, the mismatch is a little too large and cannot be explained by measurement errors, in my opinion.
Can you please help me here. What am I overlooking?