[Location] Localized in the erect sitting position and with arm holddown unforcedly. Posterior and inferior to the shoulder joint, when the arm is adducted, the point is 1.0 cun above the posterior end of the axillary fossa. ( Fig.27 )
 
[Regional Anatomy] Skin→subcutaneous tissue→the back share of deltoid→triceps brachii→teres major-latissimus dorsi tendon. Superficial layer, the lateral cutaneous branches of the second intercostal nerve, and the posterior antebrachial cutaneous nerve; deep layer, the radial nerve.