Anterior and Posterior Compartment of Arm (Muscles)

Anterior Compartment of Arm

(1) Biceps Brachii

Origin

The biceps muscle has two heads

(a) The short head and

Origin at the coracoid process of scapula

(b) The long head

Origin at supraglenoid tubercle of the scapula

Insertion

Inserts at radial tuberosity and bicipital aponeurosis into deep fascia on medial part of forearm

Artery Supply

Brachial artery

Nerve Supply

Musculocutaneous Nerve

Action

Flexion of Elbow

Supination of forearm

Clinical Significance

Biceps tendonitis/tendinosis/tendinopathy

(2) Coracobrachialis

Origin

Coracoid process of scapula

Insertion

Anteromedial surface of humerus distal to crest of lesser tubercle

Artery Supply

Brachial Artery

Nerve Supply

Musculocutaneous Nerve

Action

Flexion and Adduction of Arm at glenohumeral joint

Clinical Significance

Coracobrachialis Tendon Rupture

(3) Brachialis

Origin

anterior surface of the humerus, specifically at the distal half of humerus

Insertion

Coronoid Process of ulna and Ulnar Tuberosity

Artery Supply

Radial recurrent artery
Brachial artery

Nerve Supply

Musculocutaneous Nerve
Radial Nerve

Action

Flexion at elbow joint

Clinical Significance

Brachialis muscle injury (rare)

Posterior Compartment of Arm

(1) Triceps Brachii

Origin

Long head
Infraglenoid tubercle of scapula

Lateral head
Above the radial groove of humerus

Medial head
Below the radial groove of humerus

Insertion

Olecranon process of ulna

Artery Supply

Brachial Artery
Posterior Circumflex Humeral Artery

Nerve Supply

Radial Nerve
Axillary Nerve

Action

Extension of elbow joint antagonist to biceps brachii.
It us also involved in retroversion and adduction of arm.

Clinical Significance

Triceps Strain (common)
Triceps Tendon Rupture

(2) Anconeous

Origin

Lateral epicondyle of humerus

Insertion

lateral surface of the olecranon process of ulna and the superior proximal part of the posterior ulna

Artery Supply

Brachial Artery
Recurrent Interosseous Artery

Nerve Supply

Radial Nerve

Action

Extension at elbow joint

Clinical Significance

Anconeus Epitrochlearis