A competitive swimmer develops a ganglion cyst at the spinoglenoid notch of the scapula, compressing the suprascapular nerve distally. Which motor deficit results?

• A Weakness of both abduction initiation and lateral rotation of the shoulder
• B Isolated weakness of lateral rotation of the shoulder ✓
• C Isolated weakness of initiating shoulder abduction
• D Weakness of shoulder adduction and internal rotation

Explanation

The suprascapular nerve from the upper trunk (C5, C6) reaches the supraspinatus after passing the suprascapular notch, then winds around the lateral edge of the scapular spine through the spinoglenoid notch to reach infraspinatus. A cyst at the spinoglenoid notch compresses only the infraspinatus branch, giving isolated loss of lateral rotation while abduction initiation stays intact. This notch level distinction is what separates the key from option A.

Reference: Snell's Clinical Anatomy by Regions, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.