Muscles of the Shoulder

Deltoid M. (anterior) Origin

clavicle, lateral third

Deltoid M. (anterior) insertion

deltoid tuberosity

Deltoid M. (anterior) Action

shoulder flexuib and medial shoulder rotation

Deltoid M. (anterior) Innervation

axillary nerve

Deltoid M. (posterior) Origin

spine of scapula

Deltoid M. (posterior) Insertion

deltoid tuberosity

Deltoid M. (posterior) action

pull humerus posteriorly

lateral shoulder rotation

Deltoid M. (posterior) Innervation

axillary nerve

Supraspinatus M. Origin

supraspinous fossa of the scapula

Supraspinatus M. insertion

greater tubercle of the hummerus

Supraspinatus M. Action

shoulder stabilization and abductuon

Supraspinatus M. Innervation

suprascapular nerve

Infraspinatus M Origin

infraspinous fossa of the scapula

Infraspinatus M Insertion

greater tubercle of the humerus

Infraspinatus M Action

shoulder stabilization

lateral rotation

Infraspinatus M Innervation

suprascapular nerve

Teres Minor M. Origin

posterolateral scapula

Teres Minor M. Insertion

greater tubercle of the humerus

Teres Minor M. Action

shoulder stabilization and lateral rotation

Teres Minor M. Innervation

axillar nerve

Teres Major M. Origin

inferior angle of the scapula

Teres Major M. Insertion

• intertubercular groove/sulcus of the humerus

Teres Major M. Action

shoulder extension

medial rotation

Teres Major M. Innervation

subscapular nerve

Subscapularis M. Origin

subscapular fossa

Subscapularis M. Insertion

lesser tubercle of the humerus

Subscapularis M. Action

shoulder stabilization

medial rotation

Subscapularis M. Innervation

Subscapular Nerve

Latissimus Dorsi M. Origin

T7-L5, lower ribs, iliac crest, thoracolumbar fascia

Latissimus Dorsi M. Insertion

intertubecular sulcus/ groove of humerus

Latissimus Dorsi M. Action

Shoulder extension

shoulder ADDuction

medial rotation

Latissimus Dorsi M. Innervation

thoracodorsal nerve

Pectoralis Major Origin

clavicle, sternum, and ribs 1-7

Pectoralis Major Insertion

intertubecular sulcus of the humerus

Pectoralis Major Action

shoulder flexion (up to 90 degrees)

ADDuction

medial rotation

Pectoralis Major Innervation

pectoral nerves

Pectoralis Minor Origin

ribs 3-5

Pectoralis Minor Insertion

coracoid process of the scapula

Pectoralis Minor Action

ABDuction

downward rotation of the scapula

depression of scapula

Pectoralis Minor Innervation

pectoralis nerves