Which nerve palsy can cause 'Winging of scapula'?

Ans. c (Long thoracic nerve) (Ref. BDC Vol. I 4th/pg. 67)- Scapular Winging may occur from long thoracic OR spinal accessory nerve injury (which denervates the trapezius).LONG THORACIC NERVE# Derived from ventral rami of C5, C6, and Cl - close to their emergence from intervertebral foramina;# It runs downwards and passes either in front of or behind middle scalene muscle; it reaches upper slip of serratus anterior muscle and descends on outer surface of this muscle, giving branches into it.Nerves related to upper extremitySr.NerveMuscle GroupFunctional Deficit or Sign1.Long thoracicSerratus anterior# Winging of scapula2.SuprascapularSupraspinatus and Infraspinatus# Difficulty in initiating arm abduction3.AxillaryDeltoid and Teres minor# Inability to fully abduct arm4.RadialExtensors of forearms, wrist, proximal phal anges and thumb# Loss of arm extension, loss of forearms extension, supination, abduction, wrist drop, loss of proximal phalangeal & thumb extension.# Saturday night palsy.5.MusculocutaneousFlexors of arm and forearm# Weak arm & forearm flexion, weak forearm supination.6.MedianWrist and hand flexors# Paralysis of flexor, pronator, and thenars, inability to flex index & middle fingers (sign of benediction).# "Pointing index finger"# Laborer's nerve.7.UlnarWrist and hand flexors# Claw Hand# Froment sign positive# Loss of thumb abduction# Ape-thumb# Tardy ulnar palsy (cubitus varus in condylar humerus )