ARM AND CUBITAL FOSSA

POSTERIOR COMPARTMENT:

Muscles:

Triceps Brachii:

Action: Powerful extensor of the elbow joint also adduction.

Innervation: radial nerve (c7 c8)

Attachments: proximally to the scapula, humerus and Intermuscular septum (lateral and medial)

Distally - olecranon process of the ulna.

Anconeus:

Action: weak extensor of forearm.

Attachments: lateral epicondyle of humerus to the upper ulna

Innervation: Radial Nerve (c7 c8)

ANTERIOR COMPARTMENT:

Three muscles:

Biceps Brachii:

Action: powerful flexion and supinates of forearm, weak flexion and abduction at shoulder joint

Innervation: Musculocutaneous nerve from the lateral cord of the brachial plexus (c5 c6)

Attachments: proximally to the scapula, humerus and distally thru the bicipital aponeurosis and medial forearm.

Coracobrachialis:

Action: weak flexor and adductor of arm at shoulder joint

Innervation: musculocutaneous nerve (c5 c6)

Attachments: proximally to the coracoid process of the scapula

Brachialis:

Action: powerful flexion of forearm.

Innervation: musculocutaneous nerve (c5 c6) - lateral cord of the brachial plexus.

Category: Anatomy Notes