During objective examination, atrophy is seen in the infraspinatus fossa. Which condition is most likely?

• A. C7 radiculopathy
• B. Subscapularis tear
• C. Suprascapular nerve palsy
• D. Dorsal scapular nerve palsy

Answer: (C)

The infraspinatus sits in the infraspinous fossa and is innervated by the suprascapular nerve. When this nerve is compromised, the infraspinatus (and often the supraspinatus) wastes away, which you’d see as atrophy in the area where the infraspinatus resides. That pattern points to suprascapular nerve palsy rather than issues with other nerves or roots. Dorsal scapular nerve palsy would affect rhomboids and levator scapulae, not the infraspinatus region. A subscapularis tear would mainly affect internal rotation and adduction, not cause isolated infraspinatus atrophy. C7 radiculopathy could weaken multiple shoulder muscles, not show a selective wasting in the infraspinatus fossa. So the most likely condition is suprascapular nerve palsy.