Shoulder Flashcards
Pectoralis Major
Origin- Medial two thirds of clavical; sternum; costal cartilages 1-6
Insertion- Lateral lip of intertubercular groove (crest of greater tubercle) of humerus
Action- Adduction and medial rotation of arm; flexion and extension of arm
Innervation- Medial and lateral pectoral nerves
Pectoralis Minor
Origin- Ribs 3-5
Insertion- Coracoid process of scapula
Action- Depression of shoulder; downward rotation of scapula
Innervation- Medial pectoral nerve
Sternocleidomastoid
Origin- Tendinous head from sternum; muscular head from medial third of clavicle
Insertion- Mastoid process of skull
Action- One muscle; flexion of neck toward same side
Innervation- Accessory nerve (cranial nerve XI)
Subclavius
Origin- Rib 1
Insertion- Undersurface of clavicle
Action- Possibly depresses clavicle; maintains sternoclavicular joint
Innervation- Nerve to subclavius
Trapezius
Origin- External occipital protuberance; ligamentum nuchae; spinous processes of seventh cervical and all thoracic vertebrae
Insertion- Spine of scapula; acromion; lateral third of clavicle
Action- Elecation of scapula (upper fibers); retraction of scapula (middle fibers); depression of scapula (inferior fibers); rotation of glenoid cavity upward
Innervation- Accessory nerve (C3 and C4 sensory)
Latissimus Dorsi
Origin- Spinous processes of lower six thoracic and all lumbar and sacral vertebrae; posterior part of iliac crest
Insertion- Medial lip (crest of lesser tubercle) and floor of intertubercular groove of humerus
Action- Extension, adduction, and medial rotations of arm
Innervation- Thoracodorsal nerve
Levator scapulae
Origin- Transverse processes of upper four cervical vertebrae
Insertion- Superior angle and upper part of medial border of scapula
Action- Elevation of scapula
Innervation- C3 and C4; dorsal scapular nerve
Rhomboid Minor
Origin- Lower part of ligamentum nuchae; spinous processes of seventh cervical and first thoracic vertebrae
Insertion- Medial border of scapula at base of spine
Action- Elevation and retraction of scapula; downward rotation of glenoid cavity
Innervation- dorsal scapular nerve
Rhomboid Major
Origin- Spinous processes of second to fifth thoracic vertebrae
Insertion- Medial border of scapula below rhomboid minor
Action- Elevation and retraction of scapula; downward rotation of glenoid cavity
Innervation- Dorsal scapular nerve
Serratus anterior
Origin- Ribs 1-8 on anterolateral thoracic wall
Insertion- Medial border of scapula; heaviest insertion to inferior angle
Action- Protraction of scapula; upward rotation of glenoid cavity; holds medial border against thoracic wall
Innervation- Long thoracic nerve
Deltoid
Origin- Lateral third of clavicle; acromion; spine of scapula
Insertion- Deltoid tuberosity on the shaft of humerus
Aciton- Abduciton (middle fibers); flexion and medial rotation (anterior fibers), and extension and lateral rotation (posterior fibers) of arm
Innervation- axillary nerve
Supreaspinatus
Origin- Supraspinous fossa of scapula
Insertion- Greater tubercle of humerus
Action- Abduction of arm
Innervation- Suprascapular nerve
Infraspinatus
Origin- Infraspinous fossa of scapula
Insertion- Greater tubercle of humerus below supraspinatus
Action- Lateral rotation of arm
Innervation- Suprascapular nerve
Teres Minor
Origin- Upper two thirds of lateral border of scapula
Insertion- Greater tubercle of humerus below infraspinatus
Action- Lateral rotation of arm
Innervation- Axillary nerve
Teres major
Origin- Inferior angle of scapula
Insertion- Medial lip of intertubercular groove of humerus
Action- Adduction, medial rotation, and extension of arm
Innervation- Lower subscapular
Subscapularis
Origin- Subscapular fossa of scapula
Insertion- Lesser tubercle and crest of humerus
Action- Medial rotation of arm
Innervation- Upper and lower subscapular nerves
Pectoralis Major
Origin- medial two thirds of clavicle; sternum; costal cartilages 1-6
Insertion- lateral lip of inter tubercular groove of humerus
Action- Adduction and medial rotation of arm; flex ion (clavicular fibers) and extension (sternocostal fibers) of arm
Innervation- medial and lateral pectoral nerves
