PEDS100 Chapter Notes -Latissimus Dorsi Muscle, Scapula, Deltoid Tuberosity
Document Summary
Muscles that move the arm: 2 muscles originate from axial skeleton: pectoralis major and latissimus dorsi, 7 muscles originate from scapula: coracobrachialis, deltoid, supraspinatus, infraspinatus, subscapularis, teres major, teres minor. Coracobrachialis: along with pectoralis major and latissimus dorsi adductors of shoulder. Deltoid:multi-pennate, opposite fibers do opposing actions in same muscle. A: whole muscle: abduction of shoulder; anterior fibers: flexion and medial rotation of humerus; posterior fibers: extension and lateral rotation of humerus. : supraspinatus, infraspinatus, teres minor, and subscapularis: rotator cuff (sits) all but subscapularis originate from posterior side of scapula. Supraspinatus: most commonly injured part of shoulder, can"t palpate. A: initiates abduction at shoulder, first 20-30 degrees of abduction, then deltoid abducts. Subscapularis: serratus anterior+subscapularis are only 2 muscles that attach to anterior side of scapula, can"t palpate. I: medial lip of intertubercular groove of humerus. Latissimus dorsi: largest muscle in body, deep to trapezius.