Scapulohumeral Muscles

origin of the deltoid

anterior: lateral end of clavicle

middle: acromion process

posterior: spine of scapula

insertion of deltoid

deltoid tuberosity of humerus

innervation of deltoid

axillary nerve

action of deltoid

anterior: flexes and medially rotates

middle: adducts

posterior: extends and laterally rotates

origin of supraspinatus

supraspinous fossa of scapula

insertion of supraspinatus

greater tubercle of humerus

innervation of supraspinatus

suprascapular nerve

action of supraspinatus

abducts shoulder and stabilizes glenohumeral joint

origin of infraspinatus

infraspinous fossa of scapula

insertion of infraspinatus

greater tubercle of humerus

innervation of infraspinatus

suprascapular nerve

action of infraspinatus

laterally rotate shoulder

origin of teres minor

lateral border of scapula

insertion of teres minor

greater tubercle of humerus

innveration of teres minor

axillary nerve

action of teres minor

laterally rotate shoulder

origin of subscapularis

subscapular fossa (anterior scapula)

insertion of subscapularis

lesser tubercle of humerus

innervation of subscapularis

upper and lower subscapular nerves

action of subscapularis

medially rotates shoulder

origin of teres major

lower lateral border of scapula

insertion of teres major

medial lip of the intertubercular groove of humerus

innervation of teres major

lower subscapular nerve

action of teres major

extends, adducts, and medially rotates shoulder