Muscles of the Arm: O/I/I/A
Muscle Origin Insertion Innervation Action
Supinates
Tuberosity of
Short head: tip of the forearm, and
radius and
coracoid process of the when it is supine,
fascia of the Musculocutaneous
Biceps Brachii scapula; Long head: flexes forearm;
forearm via the nerve (C5, C6*)
supraglenoid tubercle of Short head resists
bicipital
the scapula dislocation of the
aponeurosis
shoulder
Coracoid
Distal half of the
process and Musculocutaneous Flexes forearm in
Brachialis anterior surface of the
tuberosity of the nerve (C5, C6*) all positions
humerus
ulna
Helps flex and
Middle third of
Musculocutaneous abduct arm;
Tip of the coracoid the medial
Coracobrachialis nerve (C5, C6*, resists
process of the scapula surface of the
C7*) dislocation of
humerus
shoulder
Long head:
Chief extensor of
infratubercle of scapula;
forearm; long
Lateral head: posterior
Proximal end of head resists
surface of the humerus,
olecranon of Radial nerve (C6, dislocation of
Triceps Brachii superior to radial
ulna and fascia C7*, C8*) humerus;
groove; Medial head:
of forearm especially
posterior surface of the
important during
humerus, inferior to the
abduction
radial groove
Assists triceps in
Lateral surface
extending
of olecranon
forearm;
Lateral epicondyle of and superior Radial nerve (C7,
Anconeus stabilizes elbow
humerus part of the C8, T1)
joint; may abduct
posterior surface
ulna during
of the ulna
pronation
