Muscles of Upper Limb: Pectoral Girdle Flashcards
Trapezius
moves scapula
actions: elevates, retracts, depresses, and rotates scapula
Origin: C1-T12 vertebrae
Insertion: scapular spine, clavicle
Serratus Anterior
moves scapula
actions: protracts and rotates scapula; holds scapula flat against ribcage
Origin: scapula
Insertion: anterior ribs
Pectoralis Major
moves glenohumeral joint
action: adducts, flexes, and medially rotates arm
Origin: sternum, clavicle, ribs
Insertion: humerus
Latissimus Dorsi
moves glenohumeral joint
action: adduct, extend, and medially rotate arm
Origin: lower back
Insertion: humerus
Teres Major
moves glenohumeral joint
action: adduct, extend, and medially rotate arm
Origin: scapula
Insertion: humerus
Deltoid
shoulder muscle
action: abducts, flexes, extends arm; flexion and rotation of arm, extension and rotation of arm
Origin: scapular spine, clavicle
Insertion: humerus
Rotator Cuff Muscles (SITS)
shoulder muscles
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Supraspinatus
shoulder muscle
action: initiates abduction of arm
Origin: scapula suprapsinous fossa
Insertion: humeral tuberosities
Infraspinatus
shoulder muscle
action: laterally rotates arm
Origin: scapula infraspinous fossa
Insertion: humeral tuberosities
Teres Minor
shoulder muscle
action: laterally rotates arm
Origin: scapula infraspinous fossa
Insertion: humeral tuberosities
Subscapularis (located on anterior side of scapula!)
shoulder muscle
action: medially rotates arm
Origin: scapula subscapular fossa
Insertion: humeral tuberosities
Rotator Cuff Muscles in Action and Injuries
Rotator cuff injuries are common, esp. from repetitive use or trauma
–ex: baseball pitchers
Usually supraspinatus muscle injured
