Muscles of the Shoulder & Back, with Pictures
Origin of deltoid?
Acromial Extremity of the clavicle and acromion and spine of scapula
Origin for pectorals major?
Clavicle, sternum, cartilages of Ribs 2-6
actions of pectoralis major?
Flexes, adducts and rotates arm medially
insertion for pectoralis major?
Greater tubercle and inter tubercle sulcus of humerus
actions of deltoid?
abducts, flexes, extends, and med/lat rotate arm.
actions of teres major?
adducts, medially rotates and extends arm at shoulder
actions of latissimus dorsi?
adducts, medially rotates and extends arm at shoulder. draws arm inferiorly and posteriorly
nerve supply for deltoid?
axillary nerve
nerve supply for teres minor?
axillary nerve
origin of coracobrachialis?
coracoid process of scapula
insertion of deltoid?
deltoid tuberosity of humerus
actions of coracobrachialis?
flexes and adducts arm at shoulder
origin for supraspinatus muscle?
from supraspinous fossa of scapula
insertion for infraspinatus muscle?
greater tubercle of humerus
insertion for supraspinatus muscle?
greater tubercle of humerus
insertion for teres minor?
greater tubercle of humerus
actions of supraspinatus muscle?
helps deltoid to abduct arm at shoulder
origin for teres major?
inferior angle of scapula
origin for infraspinatus muscle?
infraspinous fossa of scapula
insertion for latissimus dorsi?
intertubercular sulcus of humerus
insertion of teres major?
intertubercular sulcus of humerus
nerve supply for pectoralis major?
lateral & medial pectoral nerves
actions of infraspinatus muscle?
laterally rotates arm at shoulder, adducts arm
actions of teres minor?
laterally rotates, extends, and adducts arm
insertion of subscapularis ?
lesser tubercle of humerus
nerve supply for teres major?
lower subscapular nerve
actions of subscapularis?
medially rotates arm at shoulder
insertion of coracobrachialis?
mid-medial surface of humerus
origin for teres minor?
middle part of lateral (axillary) border of scapula
nerve supply for coracobrachialis?
musculocutaneous
origins for latissimus dorsi?
spines of lower 6 thoracic vertebrae, lumbar vertebrae, iliac crest via thoracolumbar fascia, sacrum, lower 3 or 4 ribs
Origin of subscapularis ?
subscapular fossa of scapula
nerve supply for infraspinatus muscle?
suprascapular nerve
nerve supply for supraspinatus muscle?
suprascapular nerve
nerve supply for latissimus dorsi?
thoracodorsal nerve
nerve supply for subscapularis?
upper and lower subscapular nerves
