Shoulder Region Muscles Flashcards
Action of Brachialis
Flexion of forearm in all positions
Action of Deltoid
Anterior part: flexes and medially rotates arm Middle part: abducts arm Posterior part: extends and laterally rotates arm
Action of Coracobrachialis
Helps flex and adduct arm; resists dislocation of shoulder
Action of Latissimus Dorsi
Extends, adducts and medially rotates humerus Raises body towards arms during climbing
Action of Levator Scapulae
Elevates and inferior rotates scapula
Action of Pectoralis Major
Adducts, internal rotation of humerus, draws scapula anteriorly and inferiorly, flexion of humerus at clavicular head, extension of humerus from a flexed position at sternocostal head
Action of Pectoralis Minor
Stabilizes scapula by drawing it inferior and anterior along the thoracic wall
Action of Rhomboid Major
Retracts scapula and rotates to depress glenoid cavity, fix scapula to thoracic wall
Action of Rhomboid Minor
Retracts scapula and rotates to depress glenoid cavity, fix scapula to thoracic wall
Action of Subclavius
Anchors and depresses clavicle
Action of Serratus Anterior
Protraction and superior rotation of scapula
Action of Subscapularis
Medial Rotation and adduction of the Humerus
Action of Teres Major
Adducts and medially rotates the arm
Action of Teres Minor
Lateral rotation of the humerus, helps hold humers in glenoid cavity of the scapula
Action of the Anconeous
Assists triceps in extending forearm, stabilizes elbow joint; may abduct ulna during pronation
Action of the Biceps Brachii
Supination of the forearm, flexion of the forearm when supinated Short head of the Biceps Brachii resists dislocation of the shoulder
Action of the Infraspinatus
Lateral rotation of the humerus, helps hold humerus in glenoid cavity of the scapula
Action of the Supraspinatus
Initiates and assists the deltoid for horizontal abduction of the humerus
Action of Trapezius
Descending part: Elevates scapula Ascending part: Depresses Scapula Middle part: Retracts scapula Rotates glenoid superiorly
Innervation of Brachialis
Musculocutaneous nerve (C5, C6)
Action of Triceps Brachii
Chief extensor of Forearm, long head resists dislocation of the humerus (important during abduction of the arm)
Innervation of Coracobrachialis
Musculocutaenous nerve (C5, C6)
Innervation of Deltoid
Axillary nerve (C5-C6)
Innervation of Latissimus Dorsi
Thoracodorsal nerve (C6, C7, C8)
Innervation of Levator Scapulae
Dorsal Scapular (C5) and Cervical Spinal Nerves (C3-C4)
Innervation of Pectoralis Major
Lateral and Medial pectoral nerves
Innervation of Pectoralis Minor
Medial pectoral nerve
Innervation of Rhomboid Minor
Dorsal Scapular nerve (C4-C5)
Innervation of Rhomboid Major
Dorsal Scapular nerve (C4-C5)
Innervation of Serratus Anterior
Long Thoracic Nerve (C5,C6,C7)
Innervation of Subclavius
Nerve to Subclavius
Innervation of Subscapularis
Upper and Lower Subscapular nerves (C5, C6, C7)
Innervation of Teres Major
Lower Scapular Nerve (C5, C6)
Innervation of Teres Minor
Axillary Nerve (C5, C6)
Innervation of the Anconeous
Radial Nerve (C7, C8, T1)
Innervation of the Biceps Brachii
Musculocutaneous nerve (C5, C6)
Innervation of the Infraspinatus
Suprascapular nerve (C5, C6)
Innervation of the Supraspinatus
Suprascapular nerve (C4, C5, C6)
Innervation of Trapezius
Accessory nerve and C3 and C4 spinal nerves
Innervation of Triceps Brachii
Radial Nerve, (C6, C7, C8)
Insertion of Biceps Brachii
Radial Tuberosity and fascia of the forearm via Bicipital aponeurosis

Insertion of Brachialis
Coronoid process and ulnar tuberosity

Insertion of Coracobrachialis
Middle 1/3 of medial surface of humerus

Insertion of Deltoid
Deltoid tuberosity of humerus

Insertion of Latissimus Dorsi
Floor of intertubercular groove of humerus

Insertion of Levator Scapulae
Medial border of scapular superior to root of spine

Insertion of Pectoralis Major
Lateral Lip of intertubercular groove of humerus

Insertion of Pectoralis Minor
Medial border of superior surface of the corocoid process

Insertion of Rhomboid Major
Medial border of scapula from level of spine to inferior angle

Insertion of Rhomboid Minor
Smooth triangular area at medial end of scapular spine

Insertion of Serratus Anterior
Anterior surface of medial border of scapula

Insertion of Subclavius
Inferior surface of middle 1/3 clavicle

Insertion of Subscapularis
Lesser tubercle of Humerus

Insertion of Teres Major
Medial lip of intertubercular groove of humerus

Insertion of Teres Minor
Inferior facet of the greater tubercle of the humerus

Insertion of the Anconeous
Lateral surface of olecranon and superior part of posterior surface of ulna

Insertion of the Infraspinatus
Middle facet of the greater tubercle of humerus

Insertion of the Supraspinatus
Superior facet of greater tubercle of humerus
Insertion of Trapezius
Lateral 1/3 of clavicle, acromion and spine of scapula

Insertion of Triceps Brachii
Olecranon process and fascia of forearm

Origin of Anconeous
Lateral epicondyle of humerus

Origin of Biceps Brachii
Short Head: Tip of Corocoid Process of scapula Long Head: Supraglenoid tubercle of Scapula

Origin of Brachialis
Distal Half of Anterior surface of Humerus

Origin of Coracobrachialis
Tip of coracoid process of scapula

Origin of Deltoid
Lateral 1/3 of clavicle, acromion, and spine of scapula

Origin of Latissimus Dorsi
Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs

Origin of Levator Scapulae
Posterior tubercles of transverse processes C1-C4 vertebrae

Origin of Pectoralis Major
Clavicular Head: Anterior Surfaces of medial 1/2 of clavicle
Sternocostal head: Anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscles

Origin of Pectoralis Minor
3rd-5th ribs near their costal cartilages

Origin of Rhomboid Major
Spinous processes of T2-T5

Origin of Rhomboid Minor
Nuchal Ligament, spinous processes of C7 and T1 vertebrae

Origin of Subclavius
Junction of 1st rib and its costal cartilages

Origin of Serratus Anterior
External surfaces of lateral ribs 1-8

Origin of Supraspinatus
Supraspinous fossa of the scapula
Origin of Subscapularis
Subscapular Fossa

Origin of Teres Major
Posterior surface of inferior angle of scapula

Origin of Teres Minor
Middle part of lateral border of scapula

Origin of Infraspinatus
Infraspinous fossa of the scapula

Origin of Trapezius
Medial 1/3 of superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes C7-T12

Origin of Triceps Brachii
Long Head: Infraglenoid tubercle of the scapula Lateral Head: Posterior surface of humerus above radial groove Medial Head: Posterior surface of humerus below radial groove
