Muscle Anatomy and Functions of the Upper Limb

What is the function of the supraspinatus muscle?

Initiates abduction of the humerus up to 15º at the glenohumeral joint.

Where does the supraspinatus muscle originate?

Supraspinous fossa of the scapula.

Where does the supraspinatus muscle insert?

greater tubercle of humerus

What nerve innervates the supraspinatus muscle?

Suprascapular nerve.

What is the function of the infraspinatus muscle?

Laterally rotates the arm at the glenohumeral joint.

Where does the infraspinatus muscle insert?

Greater tubercle of the humerus.

where does the infraspinatus muscle originate?

infraspinous fossa of scapula

What nerve innervates the infraspinatus muscle?

Suprascapular nerve.

What is the function of the teres minor muscle?

Laterally rotates the arm at the glenohumeral joint when the arm is adducted.

Where does the teres minor muscle originate?

Dorsal surface of the scapula along the lateral margin.

where does the teres minor muscle insert?

greater tubercle of humerus

What nerve innervates the teres minor muscle?

Axillary nerve.

What is the function of the subscapularis muscle?

Medially rotates the arm at the glenohumeral joint.

Where does the subscapularis muscle originate?

Subscapular fossa of the scapula.

Where does the subscapularis muscle insert?

lesser tubercle of humerus

What nerves innervate the subscapularis muscle?

Upper and lower subscapular nerves.

What is the function of the teres major muscle?

Medially rotates and extends the arm at the glenohumeral joint.

Where does the teres major muscle originate?

Inferior angle of the scapula.

Where does the teres major muscle insert?

Medial border of intertubercular sulcus of humerus

What nerve innervates the teres major muscle?

Lower subscapular nerve.

What is the primary function of the deltoid muscle?

Abducts the arm beyond the initial 15º, flexes the arm (clavicular fibers), and extends the arm (posterior fibers) at the glenohumeral joint.

Where does the deltoid muscle insert?

Deltoid tuberosity of the humerus.

Where does the deltoid muscle originate?

anterior border of lateral 1/3 of clavicle, acromion and spine of scapula

What nerve innervates the deltoid muscle?

axillary nerve

What is the function of the coracobrachialis muscle?

Flexes and adducts the arm at the glenohumeral joint.

Where does the coracobrachialis muscle originate?

Tip of the coracoid process of the scapula.

Where does the coracobrachialis muscle insert?

Medial side of humerus on the midshaft

What nerve innervates the coracobrachialis muscle?

Musculocutaneous nerve.

What is the function of the brachialis muscle?

Flexes the forearm at the elbow joint.

Where does the brachialis muscle insert?

Tuberosity of the ulna.

Where does the brachialis muscle originate?

anterior aspect of humerus

What nerve innervates the brachialis muscle?

Musculocutaneous nerve.

What is the function of the pectoralis major muscle?

Flexion, adduction, and medial rotation at the glenohumeral joint, flexion of extended arm at GH (clavicular head), extension of flexed arm at GH (sternocostal head)

Where does the pectoralis major muscle insert?

lateral border of intertubercular sulcus of humerus

Where does the pectoralis major muscle originate?

Medial half of the anterior surface of the clavicle (clavicular head); anterior surface of the sternum, costal cartilages 1-7, and 6th rib (sternocostal head).

What nerves innervate the pectoralis major muscle?

Medial and lateral pectoral nerves.

What is the function of the pectoralis minor muscle?

Abducts (protracts) the scapula and depresses the lateral angle of the scapula.

Where does the pectoralis minor muscle originate?

Anterior surface of ribs 3-5.

Where does the pectoralis minor muscle insert?

coracoid process of scapula

What nerve innervates the pectoralis minor muscle?

Medial pectoral nerve.

What is the function of the serratus anterior muscle?

Abducts (protracts), rotates, and fixes the scapula.

Where does the serratus anterior muscle insert?

Medial border of the scapula on the anterior surface.

Where does the serratus anterior muscle originate?

lateral surfaces of ribs 1-8/9

What nerve innervates the serratus anterior muscle?

Long thoracic nerve.

What is the function of the latissimus dorsi muscle?

Extends, adducts, and medially rotates the humerus at the glenohumeral joint.

Where does the latissimus dorsi muscle originate?

Spinous processes of T7-sacrum, iliac crest, ribs 10-12.

Where does the latissimus dorsi muscle insert?

floor of intertubercular sulcus of humerus

What nerve innervates the latissimus dorsi muscle?

Thoracodorsal nerve.

What is the function of the long head of the biceps brachii muscle?

Flexes forearm at the elbow joint, supinates forearm, and aids flexion at the glenohumeral joint.

Where does the long head of the biceps brachii muscle originate?

Supraglenoid tubercle of the scapula.

Where does the long head of the biceps brachii muscle insert?

radial (bicipital) tuberosity of radius

What nerve innervates the long head of the biceps brachii muscle?

Musculocutaneous nerve.

What is the function of the short head of the biceps brachii muscle?

Flexes forearm at the elbow joint, supinates forearm.

Where does the short head of the biceps brachii muscle originate?

Coracoid process of the scapula.

Where does the short head of the biceps brachii muscle insert?

radial (bicipital) tuberosity of radius

What nerve innervates the short head of the biceps brachii muscle?

Musculocutaneous nerve.

What is the function of the long head of the triceps brachii muscle?

Extends forearm at elbow joint, extends and adducts arm at glenohumeral joint.

Where does the long head of the triceps brachii muscle originate?

Infraglenoid tubercle of the scapula.

Where does the long head of the triceps brachii muscle insert?

olecranon of ulna

What nerve innervates the long head of the triceps brachii muscle?

Radial nerve.

What is the function of the medial head of the triceps brachii muscle?

Extends forearm at elbow joint.

Where does the medial head of the triceps brachii muscle originate?

Posterior surface of the humerus on the midshaft.

Where does the medial head of the triceps brachii muscle insert?

olecranon of ulna

What nerve innervates the medial head of the triceps brachii muscle?

Radial nerve.

What is the function of the lateral head of the triceps brachii muscle?

Extends forearm at elbow joint.

Where does the lateral head of the triceps brachii muscle originate?

Posterior surface of the humerus.

Where does the lateral head of the triceps brachii muscle insert?

olecranon of ulna

What nerve innervates the lateral head of the triceps brachii muscle?

Radial nerve.

What is the function of the brachioradialis muscle?

Flexes the elbow.

Where does the brachioradialis muscle originate?

Lateral edge of the humerus above the lateral epicondyle.

Where does the brachioradialis muscle insert?

lateral side of the distal end of the radius

What nerve innervates the brachioradialis muscle?

Radial nerve.

What is the function of the pronator teres muscle?

Pronates forearm.

Where does the pronator teres muscle originate?

Medial epicondyle of the humerus (humeral head), coronoid process of the ulna (ulnar head).

Where does the pronator teres muscle insert?

lateral side of radius on the midbone

What nerve innervates the pronator teres muscle?

Median nerve.

What is the function of pronator quadratus muscle?

pronates forearm

Where does the pronator quadratus originate?

distal anterior surface of ulna

Where does the pronator quadratus insert?

distal anterior surface of radius

What is the innervation of pronator quadratus?

anterior interosseous nerve (off median nerve)

What is the function of the flexor carpi radialis muscle?

Flexes and abducts the wrist joint.

Where does the flexor carpi radialis muscle originate?

Medial epicondyle of the humerus.

Where does the flexor carpi radialis muscle insert?

palmar surface of base of metacarpals II and II

What nerve innervates the flexor carpi radialis muscle?

Median nerve.

What is the function of the flexor carpi ulnaris muscle?

Flexes and adducts the wrist joint.

Where does the flexor carpi ulnaris muscle originate?

Medial epicondyle of the humerus (humeral head), olecranon of the ulna (ulnar head).

Where does the flexor carpi ulnaris muscle insert?

pisiform, hamate, palmar surface of base of metacarpal V

What nerve innervates the flexor carpi ulnaris muscle?

Ulnar nerve.

What is the function of the palmaris longus?

flexes the wrist joint

Where does the palmaris longus originate?

medial epicondyle of humerus

Where does the palmaris longus insert?

palmar aponeurosis of hand

What nerve innervates the palmaris longus?

median nerve

What is the function of the flexor digitorum superficialis muscle?

Flexes proximal interphalangeal joints of digits 2-5, metacarpophalangeal joints, and wrist.

Where does the flexor digitorum superficialis muscle originate?

Medial epicondyle of the humerus, radius, coronoid process of the ulna.

Where does the flexor digitorum superficialis muscle insert?

4 tendons attach to palmar surfaces of middle phalanges of digits 2-5

What nerve innervates the flexor digitorum superficialis muscle?

Median nerve.

What is the function of the flexor digitorum profundus muscle?

Flexes distal interphalangeal joints of digits 2-5, metacarpophalangeal joints, and wrist.

Where does the flexor digitorum profundus muscle originate?

Anterior and medial surfaces of ulna, anterior medial half of interosseous membrane.

Where does the flexor digitorum profundus muscle insert?

4 tendons attach to palmar surfaces of distal phalanges of digits 2-5

What nerves innervate the flexor digitorum profundus muscle?

Median nerve (lateral half), ulnar nerve (medial half).