Jian Zhong is a point on the Large Intestine Channel. It is located on the center of the deltoid muscle 2.5 cun distal to LI 15, on the line between Li 15 and Li 11.*
To locate this point properly, the arm must be bent! You can’t get the right alignment without that and you can’t find the epicondyle at the shoulder.
Palpation is the key! This is easier in a slight person, but the more muscular or fat the body is, the harder you have to press. Jian Zhong is just below the epicondyle of the humerus. Palpate with your fingertip first, then palpate the same area with your fingernail to locate the margin of the bone.
Slide the acupuncture needle right next to the bone.
*You can also use your 3 cun measurement down from Li 15 first, then up ½ cun.