Long thoracic nerve supplies which of the following muscles?
Ans. a (Serratus anterior) (Ref. BDC Vol. I, 4th ed., 67)LONG THORACIC NERVE OF BELL# Derived from ventral rami of C5, C6, and C7 - close to their emergence from intervertebral foramina;# It runs downward 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;# Scapular Winging: may occur from long thoracic nerve injury or from spinal accessory nerve injury (which deinnervates the trapezius)Sr.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 phalanges and thumb# Loss of arm extension, loss of foreams extension, supination, abduction, loss of wrist extension (wrist drop), loss of proximal phalangeal extension and thumb extension.# Saturday night palsy.5.Musculocuta- neousFlexors of arm and forearm# Weak arm and forearm flexion, weak forearm supination.6.MedianWrist and hand flexors# Paralysis of flexor, pronator, and thenar muscles, inability to fully flex the index and middle fingers (Sign of benediction),# "Pointing index finger",# Labourer's nerve,# Ape-thumb deformity.7.UlnarWrist and hand flexors# Musician nerve# Inability to extend the distal and middle phalanges (Clawhand);# Loss of thumb abduction; Froment sign positive;# Tardy ulnar palsy (cubitus varus in condylar humerus fracture)Also know:Palsy of Median nerveMNEMONIC: SLAPFeaturesSign of benedictionLabourer's nerveApe-thumb deformityPointing index fingerUlnar nerveFACTFroment signAbduction of thumb lostClaw handTardy palsy due to cubitus varus
Serratus anterior
Teres minor
Supraspinatus
Infraspinatus
Upper Extremity