Which muscle paralysis can cause 'Winging of scapula'?

Ans. a (Serratus anterior) (Ref. Maheshwari orthopedics 4th/56)LONG THORACIC NERVE# Arises from ventral rami of C5, C6, and C7.# Descends behind the brachial plexus on the lateral surface of the serratus anterior, to which it supplies.# The serratus anterior muscle can be examined by asking patient to push against a wall with both hands. Winging of scapula will be typically noted.