Shoulder OIA

Subscapularis Origin

Subscapularis Origin

subscapular fossa

Subscapularis Insertion

lesser tubercle of the humerus

Subscapularis Action

internal rotation, humeral head stabilization

Supraspinatus Origin

supraspinatous fossa of scapula

Supraspinatus Insertion

greater tubercle of humerus

Supraspinatus Action

abduction, humeral head stabilization

Infraspinatus Origin

infraspinatous fossa of scapula

Infraspinatus Insertion

greater tubercle of humerus

Infraspinatus Action

external rotation, humeral head stabilization

Teres Minor Origin

lateral border of scapula

Teres Minor Insertion

greater tubercle of humerus

Teres Minor Action

external rotation, humeral head stabilization

Pectoralis Major Origin

Clavicular: anterior surface of the sternal ½ clavicle

Sternal: anterior surface of the sternum and cartilages of ribs 1-6 or 7

Pectoralis Major Insertion

greater tubercle of humerus

Pectoralis Major Action

adduction, internal rotation, flexion, extension

Pectoralis Minor Origin

superior margins and outer surface ribs 3-5 near cartilages

Pectoralis Minor Insertion

coracoid process of the scapula

Pectoralis Minor Action

depression, abduction, internal rotation, downward rotation

Teres Major Origin

dorsal surface of inferior angle

Teres Major Insertion

lesser tuberosity of the humerus

Teres Major Action

shoulder adduction, extension, and internal rotation

Rhomboidus Major Origin

Spinous process of vertebrae T2-T5

Rhomboidus Major Insertion

Medial border of scapula (from inferior angle to root of spine of scapula)

Rhomboidus Major Action

Retract scapula and rotate it to depress glenoid cavity; fix scapula to thoracic wall

Rhomboidus Minor Origin

Nuchal ligament, Spinous processes of vertebrae C7-T1

Rhomboidus Minor Insertion

Root (medial end) of spine of scapula

Rhomboidus Minor Action

Retracts and rotates scapula, fixes scapula to thoracic wall

Trapezius Origin

occipital bone, ligamentum nuchae, spinous processes of c7-T12.

Trapezius Insertion

lateral clavicle, acromion process, and spine of the scapula

Trapezius Action

elevate, rotate, and adduct the scapula

Deltoid Origin

lateral third of the clavicle, acromion process, and spine of the scapula

Deltoid Insertion

Deltoid tuberosity of humerus

Deltoid Action

shoulder abduction, flexion, internal rotation, extension and external rotation

Latissimus Dorsi Origin

posterior layer of lumbodorsal fascia, then attaching to the T6-T-12, lumbar sacral vertebrae

Latissimus Dorsi Insertion

intertubercular groove (the distal aspect)

Latissimus Dorsi Action

glenohumeral adduction, extension and internal rotation

Levator Scapulae Origin

Transverse processes of vertebrae C1-C4

Levator Scapulae Insertion

Medial border of scapula (from superior angle to root of spine of scapula)

Levator Scapulae Action

scapular elevation

Serratus Anterior Origin

outer surfaces and superior border of the ribs 1-9

Serratus Anterior Insertion

ventral scapular surface on the medial border from superior angle to inferior angle

Serratus Anterior Action

protraction, upward rotation