BIO 310 Practical 2 Muscle Table

Trapezius Origin

Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of C7-T12

Trapezius Insertion

Lateral 1/3 of clavicle, acromion, spine of scapula

Trapezius Action

Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula

Latissimus Dorsi Origin

Spinous Processes of T7-L5, sacrum, iliac crest, and ribs 10-12

Latissimus Dorsi Insertion

Floor of intertubercular sulcus of humerus

Latissimus Dorsi Action

Extends, adducts, and medially rotates humerus

Levator Scapulae Origin

Transverse Processes of C1 to C4

Levator Scapulae Insertion

Upper portion of medial border of the scapula

Levator Scapulae Action

Elevates the scapula

Rhomboids Origin

Spinous processes of C7-T5

Rhomboids Insertion

Medial Border of scapula between the spine and inferior angle

Rhomboids Action

Retracts (adducts) and elevates scapula

Deltoid Origin

Inferior edge of the crest of the spine of the scapula, lateral margin of the acromion, anterior border of lateral 1/3 of clavicle.

Deltoid Insertion

Deltoid tuberosity of humerus

Deltoid Action

Major abductor of arm; clavicular fibers assist in flexing the arm; posterior fibers assist in extending the arm

Pectoralis Major Origin

Medial half of clavicle and anterior surface of sternum, first seven costal cartilages, aponeurosis of external oblique

Pectoralis Major Insertion

Lateral lip of intertubercular sulcus of humerus

Pectoralis Major Action

Adduction, medial rotation, and flexion of the humerus at the shoulder joint

Pectoralis Minor Origin

Anterior surfaces of the third, fourth, and fifth ribs and deep fascia overlying the related intercostal spaces

Pectoralis Minor Insertion

Coracoid process of scapula

Pectoralis Minor Action

Depresses tip of shoulder; protracts scapula

Serratus Anterior Origin

Lateral surfaces of upper 8-9 ribs and deep fascia overlying the related intercostal spaces

Serratus Anterior Insertion

Costal surface of medial border of scapula

Serratus Anterior Action

Protraction and rotation of the scapula, keeps medial border and inferior angle of scapula opposed to thoracic wall

Trapezius Innervation

Motor: accessory nerve [XI]; proprioception: C3 and C4

Latissimus Dorsi Innervation

Thoracodorsal nerve (C6 to C8)

Levator Scapulae Innervation

C3 to C4 and dorsal scapular nerve (C4, C5)

Anterior Scalene Origin

Anterior tubercles of the transverse processes of vertebrae C3 to C6

Anterior Scalene Insertion

Scalene tubercle and upper surface of rib 1

Anterior Scalene Action

Elevation of rib I

Anterior Scalene Innervation

Anterior rami of C4 to C7

Rhomboids Innervation

Dorsal scapular nerve (C4, C5)

Deltoid Innervation

Axillary nerve [C5, C6]

Pectoralis Major Innervation

Medial and lateral pectoral nerves

Pectoralis Minor Innervation

Medial pectoral nerves

Serratus Anterior Innervation

Long thoracic nerve [C5, C6, C7]

Supraspinatus Origin

 Medial 2/3s of the supraspinous fossa of the scapula and the deep fascia that covers the muscle

Supraspinatus Insertion

Most superior facet on the greater tubercle of the humerus

Supraspinatus Action

Rotator cuff muscle; participates in abduction of the glenohumeral joint; stabilization of glenohumeral joint

Supraspinatus Innervation

Suprascapular nerve [C5, C6]

Infraspinatus Origin

Medial 2/3s of the infraspinous fossa of the scapula and the deep fascia that covers the muscle

Infraspinatus Insertion

Middle facet on posterior surface of the greater tubercle of the humerus

Infraspinatus Action

Rotator cuff muscle: lateral rotation of arm at the glenohumeral joint; stabilization of glenohumeral joint

Infraspinatus Innervation

Suprascapular nerve [C5, C6]

Teres Minor Origin

Upper 2/3s of a flattened strip of bone on the posterior surface of the scapula immediately adjacent to the lateral border of the scapula

Teres Minor Insertion

Inferior facet on the posterior surface of the greater tubercle of the humerus

Teres Minor Action

Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint; stabilization of glenohumeral joint

Teres Minor Innervation

Axillary nerve [C5, C6]

Subscapularis Origin

Medial 2/3s of subscapular fossa

Subscapularis Insertion

Lesser tubercle of humerus

Subscapularis Action

Rotator cuff muscle; medial rotation of the arm at the glenohumeral joint

Subscapularis Innervation

Upper and lower subscapular nerves (C5, C6, C7)

Teres Major Origin

Elongate oval area on the posterior surface of the inferior angle of the scapula

Teres Major Insertion

Medial lip of the intertubercular sulcus on the anterior surface of the humerus

Teres Major Action

Medial rotation and extension of the arm at the glenohumeral joint; stabilization of glenohumeral joint

Teres Major Innervation

Inferior subscapular nerve [C5, C6, C7]

Biceps Brachii Origin (Long and Short head)

Long head: supraglenoid tubercle of scapula; Short head: apex of coracoid process

Biceps Brachii Insertion

Radial tuberosity

Biceps Brachii Action

Powerful flexor of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the arm at the glenohumeral joint

Biceps Brachii Innervation

Musculocutaneous nerve [C5, C6]

Coracobrachialis Origin

Apex of coracoid process

Coracobrachialis Insertion

Linear roughening on mid-shaft of humerus on medial side

Coracobrachialis Action

Flexor of the arm at the glenohumeral joint; adducts arm

Coracobrachialis Innervation

Musculocutaneous nerve [C5, C6, C7]

Brachialis Origin

Anterior aspect of humerus (medial and lateral surfaces) and adjacent intermuscular septae

Brachialis Insertion

Tuberosity of the ulna

Brachialis Action

Powerful flexor of the forearm at the elbow joint

Brachialis Innervation

Musculocutaneous nerve [C5, C6]; (small contribution by the radial nerve [C7] to lateral part of muscle)

Brachioradialis Origin

Proximal part of lateral supraepicondylar ridge of humerus and adjacent intermuscular septum

Brachioradialis Insertion

Lateral surface of distal end of radius

Brachioradialis Action

Accessory flexor of elbow joint when forearm is mid-pronated

Brachioradialis Innervation

Radial nerve [C5, C6] before division into superficial and deep branches

Triceps Brachii Origin (Long, Medial, and Lateral Head)

Long head: infraglenoid tubercle of scapula; Medial head: posterior surface of humerus; Lateral head: posterior surface of humerus

Triceps Brachii Insertion

Olecranon

Triceps Brachii Action

Extension of the forearm at the elbow joint. Long head can also extend and adduct the arm at the shoulder joint

Triceps Brachii Innervation

Radial nerve [C6, C7, C8]

Pronator Quadratus Origin

Linear ridge on distal anterior surface of ulna

Pronator Quadratus Insertion

Distal anterior surface of radius

Pronator Quadratus Action

Pronation (of forearm)

Pronator Quadratus Innervation

Median nerve (anterior interosseous nerve) [C7, C8]

Pronator Teres Origin

Humeral head: medial epicondyle and adjacent supraepicondylar ridge; Ulnar head: medial side of coronoid process

Pronator Teres Insertion

Roughening on lateral surface, mid-shaft of radius

Pronator Teres Action

Pronation (of forearm)

Pronator Teres Innervation

Median nerve [C6, C7]

Supinator Origin

Superficial layer: lateral epicondyle of humerus, radial collateral and annular ligaments; Deep layer: supinator crest of the ulna

Supinator Insertion

Lateral surface of radius superior to the anterior oblique line

Supinator Action

Supination

Supinator Innervation

Posterior interosseous nerve [C6, C7]

Flexors of the Hand and Wrist Origin

Medial epicondyle of the humerus; proximal parts of the ulna and radius

Flexors of the Hand and Wrist Insertion

Anterior aspects of the metacarpal bones, phalanges, and sometimes the carpal bones

Flexors of the Hand and Wrist Action

Flexion of the hand at the wrist

Flexors of the Hand and Action Innervation

Mostly median nerve, a couple are ulnar nerve

Extensors of the Hand and Wrist Origin

Lateral epicondyle of the humerus; posterior surfaces of the ulna and radius

Extensors of the Hand and Wrist Insertion

Posterior aspects of the metacarpal bones and phalanges

Extensors of the Hand and Wrist Action

Extension of the hand at the wrist

Extensors of the Hand and Wrist Innervation

Radial nerve

Iliacus Origin

Upper 2/3s of iliac fossa, anterior sacro-iliac and iliolumbar ligaments, and upper lateral surface of sacrum

Iliacus Insertion

Lesser trochanter of femur

Iliacus Action

Flexion of thigh at hip joint

Iliacus Innervation

Femoral nerve (L2 to L4) Anterior rami of L1 to L3