The shoulder and arm Flashcards
Descending
Part of
Trapezius
Origin: External occipital protuberance and
superior nuchal line of occipital bone,
nuchal ligament, spinous process of C7 vertebra.
Insertion: Posterior aspect of lateral one
third of clavicle, acromion of scapula.
Action: Elevates, retracts, and upwardly rotates the pectoral (shoulder) girdle at
acromioclavicular and sternoclavicular
joints; extends and laterally flexes head and neck.
Innervation: Accessory nerve, anterior rami
of third and fourth cervical nerves
Transverse
Part of
Trapezius
Origin: Spinous processes of C7-T4 vertebrae.
Insertion: Acronion of scapula, medial half of spine of scapula.
Action: Retracts the pectoral (shoulder)
girdle at acromioclavicular and sternoclavicular joints.
Innervation: Accessory nerve, anterior rami
of third and fourth cervical nerves
Ascending Part
of Trapezius
Origin: Spinous processes of T5-T12 vertebrae.
Insertion: Medial half of spine of scapula.
Action: Depresses, retracts, and upwardly rotates the pectoral (shoulder) girdle at
acromioclavicular and sternoclavicular joints.
Innervation: Accessory nerve, anterior rami
of third and fourth cervical nerves.
Levator
Scapulae
Origin: Transverse processes of C1-C4 vertebrae
Insertion: Superior angle of scapula, medial
border of scapula superior to spine of scapula.
Action: Elevates and downwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints; extends and laterally flexes neck
Innervation: Anterior rami of third and fourth cervical nerves, dorsal scapular nerve(C5).
Rhomboid
Minor + Major
Origin: Nuchal ligament and spinous
processes of C7-T5 vertebrae.
Insertion: Medial border of scapula.
Action: Retracts and downwardly rotates
pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.
Innervation: Dorsal scapular nerve (C4-C5).
Serratus
Anterior
Origin: External surfaces of first to ninth ribs.
Insertion: Medial border of scapula.
Action: Protracts and upwardly rotates
pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.
Innervation: Long thoracic nerve (C5-C7).
Subclavius
Origin: Superior surface of costal of end of
first rib and adjacent first costal cartilage.
Insertion: Inferior surface of the middle one third of clavicle.
Action: Stabilizes clavicle.
Innervation: Nerve to subclavius muscle (C5-C6).
Pectoralis
Minor Muscle
Origin: Anterior ends of third to fifth ribs
Insertion: Coracoid process of scapula.
Action: Protracts and downwardly rotates
pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints.
Innervation: Medial and lateral pectoral
nerves (C5-T1)
Pectoralis
Major
Origin: Clavicular head: anterior aspects of
medial half of clavicle; Sternocostal head:
manubrium, sternal body, the true ribs and
their costal cartilages; Abdominal part:
external abdominal oblique aponeurosis
Insertion: Crest of greater tubercle of humerus OR lateral lip of bicipital groove.
Action: Adducts, medially rotates, and
transversely adducts arm at glenohumeral
(shoulder) joint; depresses pectoral
(shoulder) girdle at acromioclavicular and sternoclavicular joints.
Innervation: Medial and lateral pectoral
nerves (C5-T1).
Latissimus
Dorsi
Origin: Spinous processes of T7-L5 via thoracolumbar fascia, ninth to twelfth ribs, iliac crest.
Insertion: Floor of intertubercular sulcus of humerus.
Action: Adducts. medially rotates, and extends arm at glenohumeral (shoulder) joint.
Innervation: Thoracodorsal nerve (C6-C8).
Teres Major
Origin: Posterior aspect of inferior angle of scapula.
Insertion: Crest of lesser tubercle of humerus.
Action: Adducts and medially rotates arm
at glenohumeral (shoulder) joint.
Innervation: Lower subscapular nerve (C5-C7).
Subscapularis
Origin: Subscapular fossa of scapula. Insertion: Lesser tubercle of humerus. Action: Medially rotates and stabilizes arm at glenohumeral (shoulder) joint. Innervation: Upper and lower subscapular nerves (C5-C7).
Supraspinatus
Origin: Supraspinous fossa of scapula. Insertion: Greater tubercle of humerus. Action: Abducts and stabilizes arm at glenohumeral (shoulder) joint. Innervation: Suprascapular nerve (C5-C6).
Infraspinatus
Origin: Infraspinous fossa of scapula. Insertion: Greater tubercle of humerus. Action: Laterally rotates, transversely abducts and stabilizes arm at glenohumeral (shoulder) joint. Innervation: Suprascapular Nerve (C5-C6).
Teres Minor
Origin: Posterior aspect of superior half of lateral border of scapula. Insertion: Greater tubercle of humerus. Action: Laterally rotates, transversely abducts and stabilizes arm at glenohumeral (shoulder) joint. Innervation: Axillary nerve (C5-C6).