SP-21 is located in which location?

• A. In the depression at the centre of the axilla
• B. On the mid-axillary line
• C. On the anterior chest wall
• D. On the posterior chest wall

Answer: (A)

SP-21 is the Great Luo-Connecting point of the Spleen, and its traditional location is in the depression at the centre of the axilla. This spot sits right in the armpit hollow, aligning with the chest region where the Spleen’s Luo-Connecting pathway travels to connect with the chest. Knowing this helps you place the point accurately when palpating the axillary area and understanding its use for issues involving the lateral chest, axilla, or chest qi disturbances. The other landmarks—mid-axillary line, or the anterior or posterior chest wall—do not correspond to SP-21’s classical location.