Superficial Back and Upper Extremity Flashcards
Trapezius (superior fibers)
O: External occipital protuberance, the medial portion of superior nuchal line of occiput, medial margin of ligamentum nuchae,
I: Posterior border of lateral 1/3 of the clavicle
A: Unilaterally: Elevation and upper rotation of the scapula; ipsilateral side bending (laterally flex) and contralateral rotation of the head;
Bilaterally: extend the head and neck
N: Accessory nerve (CN XI) and branches of C3, C4
Trapezius (middle fibers)
O: Inferior aspect of ligamentum nuchae, spinous proces of 7th cervical and upper thoracic
I: Medial margin of acromion process of scapula, superior lip of posterior border of spine of
scapula
A: Retraction of scapula, adduct scapula, stabilize scapula
N: CN XI and C3, C4
Trapezius (inferior fibers)
O: Spinous process of inferior thoracic vertebrae
I: Medial end of the spine of scapula
A: Depression of the scapula, upwardly rotate the scapula
N: CN XI and C3, C4
Rhomboid Major:
O: Spinous processes of T2 - T5 vertebrae
I: Posterior surface of medial border of scapula from the root of the spine of the scapula to the
inferior angle
A: Elevates and retracts the scapula, adduct the scapula, downwardly rotate the scapula
N: Dorsal scapular nerve (C4-C5)
Rhomboid Minor:
O: Lower end of ligamentum nuchae and spinous process of C7 and T1 vertebrae
I: Posterior surface of medial border of scapula at the root of the spine of the scapula
A: Elevates and retracts the scapula, adduct the scapula, downwardly rotate the scapula
N: Dorsal scapular nerve (C4-C5)
Levator Scapulae
O: Transverse processes of C1-C4 vertebrae at the posterior tubercles
I: Posterior surface of medial border of scapula from superior angle to root of spine of the scapula
A: Unilaterally: Elevates scapula; ipsilateral side bending and ipsilateral rotation of the head, downwardly rotate the scapula
Bilaterally: extend the head and neck
N: Anterior rami of C3 and C4 spinal nerves and by branches (C5) from the dorsal scapular nerve
Latissimus Dorsi
O: Spinous processes of T7-T12 and related interpinous ligaments; via the thoracolumbar fascia to
the spinous process of the lumbar vertebrae, related interspinous ligaments, and posterior iliac crest; last three or four ribs, inferior angle of the scapula
I: Floor of the intertubercular sulcus (or groove)
A: Adduction, medial rotation, and extension of the arm at glenohumeral joint,
N: Thoracodorsal nerve (C6,C7,C8)
Teres Major
O: Lower one third of lateral border of the scapula
I: Medial lip of intertubercular sulcus on the anterior surface of the humerus; crest of the lesser tubercle of the humerus
A: Medial rotation, extension of the arm, and adduction at the glenohumeral joint
N: lower subscapular nerve (C5, C6)
Deltoid (posterior fibers)
O: Inferior edge of the crest of the spine of the scapula
I: Deltoid tuberosity of the humerus
A: Abduct, extension, horizontal abduction, external rotation - humerus
N: Axillary (C5, C6)
Deltoid (middle fibers)
O: Lateral margin of the acromion
I: Deltoid tuberosity of the humerus
A: Abduction of humerus
N: Axillary (C5, C6)
Deltoid (anterior fibers)
O: Anterior border of the lateral 1/3 of clavicle
I: Deltoid tuberosity of the humerus
A: Abduct, flexion, horizontal adduction, internal rotation of the humerus
N: Axillary (C5, C6)
Pectoralis major
O: Clavicular head - anterior surface of medial half of clavicle;
Sternocostal head - anterior surface of the sternum; first seven costal cartilages; sternal end of the sixth rib; aponeurosis of external oblique
I: Lateral lip of the intertubercular sulcus of humerus; crest of greater tubercle of humerus
A: All fibers: adduction of glenohumeral (GH) joint, and medial rotation of glenohmeral joint; assist to elevate the thorax during forced inhalation with arm fixed; horizontal adduction of GH joint
Clavicular head: flexion of the extended shoulder
Sternocostal head: extension of the flexed shoulder
N: Medial and lateral pectoral nerves (C5-T1)
Clavicular head: lateral pectoral (C5, C6)
Sternocostal head: lateral and medial pectoral nerves (C7, C8, T1)
Pectoralis minor
O: Anterior surface of the superior borders of third to fifth ribs; and from deep fascia overlying the
related intercostal spaces
I: Coracoid process of scapula (medial border and upper surface)
A: Stabilization of the scapula against thoracic wall by pulling the coracoid process anteriorly,
downward rotation of the scapula; depression of the scapula, abduction of the scapula,
N: Medial pectoral nerve (C8, T1) (some with fibers from the communicating branch of the lateral pectoral nerve C6, C7,C8,T1)
Subclavius
O: First rib at junction between rib and costal cartilage
I: Groove on inferior surface of middle one-third of clavicle
A: Anchors and stabilizes the sternoclavicular joint; depresses the clavicle, draws clavicle anteriorly, elevates first rib (assisting with inhalation)
N: nerve to subclavius (i.e. subclavian nerve) (C5,C6)
Serratus anterior
O: Lateral (i.e. external) surfaces of upper 8-9 ribs and deep fascia overlying the related intercostal spaces
I: Costal (i.e. anterior) surface of medial border of scapula
A: With the origin fixed: abduct/protraction of the scapula, upwardly rotate the scapula, depresses the scapula, holds the medial and inferior borders of the scapula against the rib cage.
With the scapula fixed: may act to elevate the thorax during forced inhalation
N: long thoracic nerve (C5, C6, C7)
Coracobrachialis
O: Apex of coracoid process
I: Linear roughening on medial midshaft of humerus;
A: Flexor of the arm at the glenohumeral joint; adducts the shoulder at the GH joint
N: Musculocutaneous nerve (C5, C6, C7)
Supraspinatus
O: Medial two-third of the supraspinous fossa of scapula and deep fascia that covers the muscle
I: Most superior facet on the greater tubercle of the humerus
A: Rotator cuff muscle, assists with maintaining glenohumeral head stability; abduction of shoulder at the glenohumeral joint
N: Suprascapular nerve (C4, C5, C6)
Infraspinatus
O: Medial two-third of the infraspinous fossa of scapula and deep fascia that covers the muscle
I: Middle facet on posterior surface of the greater tubercle of the humerus
A: Rotator cuff muscle, assists with maintaining glenohumeral head stability; lateral rotation of the arm at glenohumeral joint, adduction of the shoulder at GH joint
N: Suprascapular nerve (C5, C6)
Teres Minor
O: Upper two-thirds of lateral border of scapula
I: Inferior facet on the posterior surface of the greater tubercle of the humerus
A: Rotator cuff muscle, assists with maintaining glenohumeral head stability; lateral rotation of the
arm at the glenohumeral joint, adduction of the shoulder at the GH joint
N: Axillary nerve (C5, C6)
Subscapularis
O: Medial two-thirds of subscapular fossa
I: Lesser tubercle of the humerus
A: Rotator cuff muscle, assist with maintaining glenohumeral head stability; medial rotation of the shoulder at the glenohumeral joint
N: Upper and lower subscapular nerves (C5, C6,C7)
Biceps brachii
O: Long head-supraglenoid tubercle of the scapula
Short head-apex of coracoid process of the scapula
I: Radial tuberosity and fascia of the forearm via bicipital apponeurosis
A: Flexion of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the
arm at the glenohumeral joint
N: Musculocutaneous nerve (C5, C6)