Muscle Origins, Insertions, and Actions

Flashcards covering the origins, insertions, and actions of key muscles in the human body.

Coracobrachialis: Origin

Coracoid process of scapula.

Coracobrachialis: Insertion

Medial surface of humerus.

Coracobrachialis: Action

Flexes, adducts upper arm; rotates upper arm medially.

Deltoid: Origin

Acromion process and spine of scapula, clavicle.

Deltoid: Insertion

Deltoid tuberosity of humerus.

Deltoid: Action

Abducts, flexes, extends upper arm.

Infraspinatus: Origin

Infraspinous fossa.

Infraspinatus: Insertion

Greater tubercle of humerus.

Infraspinatus: Action

Extends upper arm, rotates upper arm laterally.

Latissimus Dorsi: Origin

Spinous processes of lower $6$ T, all L and S vertebrae, iliac crest, ribs.

Latissimus Dorsi: Insertion

Intertubercular sulcus of humerus.

Latissimus Dorsi: Action

Adducts upper arm; rotates arm medially.

Levator Scapulae: Origin

Transverse processes of C1-C4.

Levator Scapulae: Insertion

Superior medial border of scapula.

Levator Scapulae: Action

Elevates scapula.

Pectoralis Major: Origin

Clavicle, sternum, and ribs 2-6.

Pectoralis Major: Insertion

Intertubercular sulcus of humerus.

Pectoralis Major: Action

Flexes shoulder, adducts upper arm; rotates upper arm medially.

Pectoralis Minor: Origin

Sternal end of ribs 3-5.

Pectoralis Minor: Insertion

Coracoid process of scapula.

Pectoralis Minor: Action

Depresses and protracts scapula; elevates ribs during forceful breathing.

Rhomboideus: Origin

Spinous processes C7, T1-T5.

Rhomboideus: Insertion

Medial border of scapula.

Rhomboideus: Action

Retracts and elevates scapula.

Serratus Anterior: Origin

Outer surface of first 8 or 9 ribs.

Serratus Anterior: Insertion

Ventral surface of scapula.

Serratus Anterior: Action

Protracts and rotates scapula.

Supraspinatus: Origin

Supraspinous fossa.

Supraspinatus: Insertion

Greater tubercle of humerus.

Supraspinatus: Action

Abducts upper arm.

Subscapularis: Origin

Subscapular fossa.

Subscapularis: Insertion

Lesser tubercle of humerus.

Subscapularis: Action

Extends upper arm, rotates upper arm medially.

Teres Major: Origin

Lateral and medial borders of scapula.

Teres Major: Insertion

Intertubercular sulcus and lesser tubercle of humerus.

Teres Major: Action

Extends shoulder; adducts upper arm; rotates upper arm medially.

Teres Minor: Origin

Lateral and medial borders of scapula.

Teres Minor: Insertion

Greater tubercle of humerus.

Teres Minor: Action

Rotates upper arm laterally.

Trapezius: Origin

Occipital bone, spinous processes of C and T vertebrae.

Trapezius: Insertion

Spine, acromion process of scapula; acromial end of clavicle.

Trapezius: Action

Elevates, depresses, retracts, and rotates scapula.