Nerves of the Upper Extremity:
Nerve
Musculocutaneous
Median
Radial
Ulnar
Axillary
Dorsal Scapular
Suprascapular
Subscapular
Innervation
All muscles in anterior
compartment of arm (Biceps
brachii, Coracobrachialis,
Brachialis)
“ 2LOAF” Most flexors of forearm,
thenar muscles in hand (Palmaris
longus, Flexor carpi radialis,
Pronator teres, Flexor digitorum
superficialis, lateral half of Flexor
digitorum profundus, Flexor
pollicis longus, Pronator
quadrates)
All muscles in posterior
compartments of arm and
forearm (Triceps brachii,
Brachioradialis, Extensor carpi
radialis longus and brevis,
Aconeus, Supinator)
As posterior interosseous nerve:
Abductor pollicis longus, Extensor
pollicis brevis and longus, Extensor
indicis, Extensor digitorum,
Extensor digiti minimi, Extensor
carpi ulnaris
Most intrinsic hand muscles
(hypothenars (OAFs), lumbricals,
interossei, Palmaris brevis,
adductor pollicis), flexor carpi
ulnaris, medial half of flexor
digitorum profundus
Deltoid, Teres minor
Injury
Weakness of flexion of arm
Carpal Tunnel: weakness of
thenar muscles (trouble
with opposition), pain and
tingling in palmar surface of
lateral 3 ½ digits and lateral
side of palm and middle of
wrist
Midshaft humerus fracture:
wrist drop due to failure of
extensor muscles, and
sensory changes in dorsum
of hand
Fracture of medial
epicondyle of humerus:
clawed hand, loss of
sensation in medial 1 ½
digits
Fracture of surgical neck of
humerus: loss of arm
abduction at shoulder
Rotator Cuff: shoulder joint
instability, weakness in
lateral rotation
Levator scapulae, Rhomboid major Scapula drifts laterally, loss
and minor
of elevation
Supraspinatus, Infraspinatus
Rotator Cuff muscles:
instability of shoulder joint,
weakness in lateral rotation
Teres Major (Inf. Ss), Subscapularis Weakness in medial
(Inf. and Sup. Ss)
rotation
Thoracodorsal
Latissimus dorsi
Long Thoracic
Serratus anterior
Medial Pectoral
Pectoralis major and minor
Lateral Pectoral
Pectoralis Major
Weakness in adduction,
medial rotation, and
extension of humerus at
shoulder joint
Winged Scapula, loss of
elevation of arm
Weakness in flexion,
adduction, and medial
rotation of arm at shoulder
and protraction of scapula
Weakness in flexion,
adduction, and medial
rotation of arm at shoulder
Special Spaces/Compartments:
Space/Compartment
Quadrangular Space
Triangular Space
Triangular Interval
Axillary Inlet
Cubital Fossa
Carpal Tunnel
Anatomical Snuffbox
Boundaries
Post: teres minor, surg. Neck of
humerus, teres major, long head
of triceps brachii
Ant: subscapularis, surg. Neck of
humerus, teres major, long head
of triceps brachii
Post: long head of triceps
brachii, teres minor, teres major
Ant: long head of triceps brachii,
teres major, subscapularis
Long head of triceps brachii,
shaft of humerus, teres major
Lateral border rib 1, posterior
surface of clavicle, superior
border of scapula
Brachioradialis and Pronator
teres, base is imaginary line
between medial and lateral
epicondyles of humerus
Pisiform, triquetrum, hamate,
capitates, trapezoid, trapezium,
and the flexor retinaculum that
spans this carpal arch
Tendons of pollicis abductor and
extensors
Contents/Significance
Axillary nerve, Posterior
circumflex humeral artery
Fracture of rib 1 or anterior
dislocation of humeral head may
compress axillary artery
(anastomoses with subclavian
artery prevent ischemia)
Circumflex scapular artery
Profunda brachii artery, radial
nerve
Axillary Artery and Vein,
Lymphatics, Axillary Nerve
Biceps brachii tendon, brachial
artery, median nerve, median
cubital vein
Median nerve, tendons of flexor
digitorum profundus and
superficialis, and tendon of
flexor pollicis longus
Carpal Tunnel Syndrome
Radial artery and nerve, cephalic
vein