Some sources locate SP-21 in which intercostal space?

• A. Seventh intercostal space
• B. Sixth intercostal space
• C. Fifth intercostal space
• D. Eighth intercostal space

Answer: (B)

SP-21 sits on the lateral chest in the sixth intercostal space along the mid-axillary line. This spot is the great Luo point of the Spleen channel, aligning with the chest area that the Spleen meridian reaches. Because the sixth space is the standard reference for this point, it’s chosen as the location in most charts and texts. Moving higher to the fifth space places you nearer the upper chest near the nipple region, while lower spaces like the seventh or eighth place you further down the chest. So the sixth intercostal space is the correct reference for SP-21.