Large Intestine 15 (Jian Yu) is one of the most commonly used local acupuncture points for shoulder pathologies. Anatomically, this point provides access to several possible targets including the supraspinatus and bicipital tendon. When needling LI 15, the position of the patient’s humerus plays an important role in biasing either of the two aforementioned tendons.
The “Ins”: Supraspinatus Tendon
When the patient’s humerus is internally rotated, LI 15 is more specific for accessing the supraspinatus tendon. When the patient lies supine, this position is achieved by having the patient place the palm of their hand over their abdomen. The supraspinatus tendon attachment at the greater tubercle will now be under the practitioner’s finger when palpating LI 15 anterior and inferior to the acromion. A majority of the tendon will be inaccessible as it passes under the acromion process.
The "Outs": Bicipital Tendon
When the patient's humerus is externally rotated, LI 15 is more specific for accessing the bicipital tendon as it courses through the intertubercular groove making it's way toward the glenoid labrum and supraglenoid tubercle. With the patient laying supine, position their arm by their side with the forearm supinated (palm facing upwards). The intertubercular groove will now be facing anteriorly at the location of LI 15. The tendon may be difficult to differentiate between the overlying deltoid although the intertubercular groove is easily located.
How to Locate the Intertubercular Groove:
Begin by palpating LI 15 with the glenohumeral joint internally rotated which places your finger tip on the greater tubercle. Slowly externally rotate the humerus and notice how your palpating finger sinks into a depression. This depression is the intertubercular groove. If you continue to externally rotate the shoulder the palpating finger will encounter another bony protuberance which is the location of the lesser tubercle.