Which SI point is on the posterior aspect of the shoulder, 1 cun superior to the posterior axillary crease when the arm hangs in the adducted position?

• A. SI 8
• B. SI 9
• C. SI 10
• D. SI 12

Answer: (A)

The question tests locating SI points on the posterior shoulder using surface landmarks. The SI point in this region sits in a depression on the posterior aspect of the shoulder, about 1 cun above the posterior axillary crease when the arm hangs by the side. That precise spot matches the standard description of this SI point, making it the best choice because it aligns with both the landmark (1 cun above the posterior axillary crease) and the anatomical location on the shoulder/scapula where the SI channel travels.

Other posterior scapular points sit in different positions relative to the scapular spine or axillary area, so their descriptions wouldn’t match the exact distance and landmark given. This is why the described location corresponds to the SI point in question.