Week 7 Anatomy

Clavipectoral fascia

The clavipectoral fascia (costocoracoid membrane; coracoclavicular fascia) is a strong fascia situated under cover of the clavicular portion of the pectoralis major. Clavipectoral fascia pierced by Cephalic vein, thoracoacromial artery and vein, lymphatics and lateral pectoral nerve.


Distubution of Cutaneous Nerves Upper Limb



See week 1 Anatomy


Sensory and motor innervation of the medial / ulnar / radial / musculocutaneous / axillary nerves.

See prior for median, ulna and radial

Musculocutaneous C5-C6

Motor (BBC) – brachialis, Biceps Brachii, Coracobrachialis

Sensory: lateral cutaneous nerve of forearm

Course: pierces the coracobrachialis muscle, near its point of insertion on the humerus. It then passes down the arm, anterior to the brachialis muscle but deep to the biceps brachii, innervating them both. The musculocutaneous nerve emerges laterally to the biceps tendon, and continues into the forearm as the lateral cutaneous nerve. It provides sensory innervation to the lateral aspect of the forearm .

Axillary C5, C6

Motor – Deltoid, teres minor

Sensory – superior lateral cutaneous nerve of arm –> lateral shoulder over regimental badge area

Course – Exit via quadrangular space.


Upper Limb Nerve injury patterns:

Brachial plexus

Upper brachial plexus – Erb’s palsy (C5 C6)

From difficult birth or blow to shoulder

Suprascapular, axillary, musculocutaneous, nerve to subclavius

Loss of sensation on lateral arm, arm hangs limp, medially rotated, extended at elbow, pronated


Lower brachial plexus – Klumpke palsy (T1)

From excess abduction – eg grabbing a branch when falling from tree

Motor loss in hand–> MCP extension and IP flexion

Sensory – medial side of arm



Axillary nerve

Anterior dislocation of glenohumoral joint

Fracture of humerus at surgical neck

Acutely pt cant abduct arm. In long standing case the deltoid wastes and the greater tubercle can be palpated.



Radial nerve

At axilla

From humerus dislocation, fracture of proximal humerus, excess pressure in axilla

Unable to extend at elbow, wrist or fingers. Hand is able to be supinated but has wrist drop.

Sensory loss over posterior arm, forearm, hand


At radial groove

From midshaft fracture of humerus

Unable to extend at wrist or fingers. Hand is able to be supinated but has wrist drop.

Sensory loss over posterior hand


At deep branch of radial nerve

From fracture of radial head or posterior dislocation of radial head

No sensory effect

Loss of everything in forearm except supinator and FCRL so no wrist drop.


At superficial radial nerve

From stabbing or laceration in forearm

No motor

Sensory loss in dorsum of hand




In axilla – rare

From stabbing

Loss of sensation over lateral forearm

Weakened but present shoulder flexion, elbow flexion and supination



Ulnar nerve

At elbow

Fracture of medial epicondyle

Motor – little and ring finger flexion/extension very reduced, no finger abduction/adduction, wrist flexion occurs with abduction of wrist. Fromons positive

Ulna sensory loss

At wrist

From laceration

Motor – little and ring finger extension very reduced, no finger abduction/adduction, wrist flexion normal. Fromons positive.

Ulna sensory loss – more likely palmar

Ulna claw – MCP hyperextension, IP flexion



Median nerve

At elbow

From supracondylar fracture

Loss of median nerve sensation, loss of most flexors and all pronators so hand constantly supinated

Hand of Benediction when pt tries to make fist – only ulna side work

At wrist

Carpal Tunnel syndrome/lacerations