Which needle direction will puncture the lung when needling HE-1 (jiquan)?

When needling HE-1 (jiquan), understanding the anatomy of the shoulder and the location of the lung is essential. HE-1 is situated in the axilla, which is quite close to the lung's apex. The correct choice of needle direction is critical to avoid potential complications, as incorrect direction could introduce a risk of pneumothorax (accidental puncture of the lung).

Puncturing the lung would occur during a medial insertion of the needle. This is because a medial insertion aims towards the center of the chest, directly parallel to the direction the lung extends. When the needle is directed medially, it has a higher likelihood of penetrating the visceral pleura surrounding the lung.

In contrast, if the needle is inserted laterally, superiorly, or inferiorly, it is directed away from the lung's location in relation to the point, significantly reducing the risk of puncturing the lung. Lateral insertion would direct the needle outward toward the arm, superior insertion would direct it toward the structures above, and inferior insertion generally follows the direction downwards, toward the humerus or axillary fat.

Given the proximity of HE-1 to the lung and the anatomical alignment of structures in the axilla, it's crucial to recognize