Muscles that move humerus Flashcards
Axial muscles that move humerus
Pectoralis major
latissimus dorsi
Scapular muscles that move humerus
Deltoid Subscapularis Supraspinatus Infraspinatus Teres major Teres minor Coracobrachialis
Pectoralis major
O: clavicle (head), sternum, costal cartilages of 2-6th ribs
I: greater tubercle and lateral lip of intertubercular sulcus of humerus
A: adducts, medially rotates arm at shoulder, clavicular head flexes arm, sternocostal head extends flexed arm
N: medial and lateral pectoral nerves
latissimus dorsi
O: spines of T7-L5, lumbar vertebrae, crests of sacrum and ilium, inferior four ribs via thoracolumbar fasica
I: intertubercular sulcus of humerus
A: extends, adducts, and medially rotate arm at shoulder joint, draw arm inferiorly and posteriorly RMA: elevates vertebral column and torso
N: thoracodorsal nerve
Deltoid
O: acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), spine of scapula (posterior fibers)
I: deltoid tuberoisty of humerus
A: lateral fibers abduct arm (first 15 degrees), anterior fibers flex and medially rotate, posterior fibers extend and laterally rotate
N: axillary nerve
Subscapularis
O: subscapular fossa of scapula
I: lesser tubercle of humerus
A: medially rotate
N: upper and lower subscapular nerve
Supraspinatus
O: supraspinous fossa of scapula
I: greater tubercle of humerus
A: assist deltoid in abduction (15-90 degrees)
N: suprascapular nerve
infraspinatus
O: infraspinous fossa of scapula
I: greater tubercle of humerus
A: laterally rotate
N: suprascapular nerve
teres major
O: inferior angle of scapula
I: medial lip of intertubercular sulcus of humerus
A: extend arm, adducts, medially rotates
N: lower subscapular nerve
teres minor
O: inferior lateral border of scapula
I: greater tubercle of humerus
A: laterally rotates and extends arm at shoulder joint
N: axillary nerve
coracocrachialis
O: coracoid process of scapula
I: middle of medial surface of shaft of humerus
A: flex and adduct arm
N: musculocutaneous nerve
