Winging of the scapula is seen in several conditions, except which one?

• A. liver disease
• B. injury to the long thoracic nerve
• C. muscular dystrophy
• D. weakness of serratus anterior muscle

Answer: (A)

Winging of the scapula happens when the muscles that hold the scapula flat against the chest wall are weakened, most importantly the serratus anterior. This muscle keeps the medial border of the scapula pressed against the thoracic wall as the arm moves. If the long thoracic nerve is injured or the serratus anterior itself is weak, the scapula cannot stay closely apposed to the rib cage, causing the medial border to protrude—classic winging.

Conditions like injury to the long thoracic nerve directly impair this stabilizing muscle, leading to winging. Muscular dystrophy can also involve scapular stabilizers, producing winging due to generalized proximal weakness. On the other hand, liver disease does not affect the muscles that stabilize the scapula, so it is not a cause of scapular winging.