Upper Extremity Muscles (Test II) Flashcards
Trapezius
O- spinous processes of C7-T12 vertebrae,
nuchal ligament,
occipital protuberence,
medial 1/3 of superior nuchal line
I- lateral 1/3 of clavicle, acromion, and spine of scapula
A- (upper) elevate scapula, (middle) retract scapula, (lower) depress scapula & superior rotation of scapula
N- spinal accessory nerve (CN XI) and C3 & C4
Latissimus Dorsi
O- spinous processes of T7-T12,
thorocolumbar fascia,
iliac crest,
inferior 3-4 ribs
I- floor of the intertubercular groove of the humerus
A- extend, adduct, and medially rotate humerus; raises the body towards the arms while climbing
N- thorocodorsal nerve (C6, C7, C8)
Rhomboid Major
O- spinous processes of T2-T5
I- medial border of scapula between the spine
A- retract and rotate the scapula to depress the glenoid; fix the scapula to the thoracic wall
N- dorsal scapular nerve (C4, C5)
Rhomboid Minor
O- spinous processes of C7-T1 and nuchal ligament
I- medial border of the scapula
A- retract and rotate the scapula to depress the glenoid; fix the scapula to the thoracic wall
N- dorsal scapular nerve (C4, C5)
Levator Scapulae
O- posterior tubercles of the transverse processes of C1-C4 vertebrae
I- medial border of the scapula superior to spine
A- elevate the scapula; tilt the glenoid inferiorly by rotating the scapula
N- dorsal scapular nerve (C3, C4, C5)
Deltoid
O- lateral 1/3 of clavicle, acromion, & spine of scapula
I- deltoid tuberosity of the humerus
A- (clavicle, anterior) flex and medially rotate the humerus
(middle) abduct the humerus
(spinal, posterior) extend and laterally rotate the humerus
N- axillary nerve (C5, C6)
Teres Major
O- superior surfaces of the inferior angle of the scapula
I- medial lip of intertubercular groove of humerus
A- medially rotate and adducts humerus
N- lower subscapular nerve (C6, C7)
Supraspinatus
O- supraspinous fossa of the scapula
I- superior facet of the greater tubercle of the humerus
A- initiate and assist the deltoid in abducting the arm; acts with the rotator cuff muscles to stabilize the humeral head in the glenoid
N- suprascapular nerve (C4, C5, C6)
Infraspinatus
O- infraspinous fossa of the scapula
I- middle facet of the greater tubercle of the humerus
A- laterally rotate the humerus; acts with the rotator cuff muscles to stabilize the humeral head in the glenoid
N- suprascapular nerve (C5, C6)
Teres Minor
O- superior part of the lateral border of the scapula
I- inferior facet of the greater tubercle of the humerus
A- laterally rotate the humerus; acts with the rotator cuff muscles to stabilize the humeral head in the glenoid
N- axillary nerve (C5, C6)
Subscapularis
O- subscapular fossa of the scapula
I- lesser tubercle of the humerus
A- medially rotate the humerus; acts with the rotator cuff muscles to stabilize the humeral head in the glenoid
N- upper and lower subscapular nerve (C5, C6, C7)
Pectoralis Major
O- (clavicular) anterior surface of medial 1/2 of clavicle
(sternocostal) anterior surface of sternum
superior 6 costal cartilages
aponeurosis of external oblique
I- lateral lip of the intertubercular groove of humerus
A- adduct and medially rotate the humerus
draw scapula anteriorly and inferiorly
(clavicular) flex humerus
(sternocostal) extend arm from flexed position
N- lateral and medial pectoral nerves
(clavicular= C5, C6) (sternocostal= C7, C8, T1)
Pectoralis Minor
O- 3rd-5th ribs near their costal cartilages
I- medial border and superior surface of coracoid process of scapula
A- stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall
N- medial pectoral nerve (C8-T1)
Serratus Anterior
O- external surfaces of lateral parts of the 1st-8th ribs
I- anterior surface of medial border of scapula
A- protracts scapula & holds it against thoracic wall; rotates scapula
N- long thoracic nerve (C5, C6, C7)
Subclavius
O- junction of 1st rib and its costal cartilage
I- interior surface of middle 1/3 of clavicle
A- anchors & depresses clavicle
N- nerve to subclavius (C5, C6)
Biceps Brachii
O- (short head) tip of coracoid process of scapula
(long head) supraglenoid tubercle of scapula
I- tuberosity of radius & fascia of the forearm (via the bicipital aponeurosis)
A- supinates the forearm; flexes forearm; and short head resists dislocation of the shoulder
N- muscutaneous nerve (C5, C6, C7)
Coracobrachialis
O- tip of coracoid process of scapula
I- middle 1/3 of medial surface of humerus
A- helps flex and adduct arm; resists dislocation of shoulder
N- musculocutaneous nerve (C5, C6, C7)
Brachialis
O- distal 1/2 of anterior surface of humerus
I- coronoid process and tuberosity of ulna
A- flexes forearm in all positions
N- musculocutaneous nerve (C5, C6) and radial nerve (C5, C7)
Triceps Brachii
O- (long head) infraglenoid tubercle of scapula
(lateral head) posterior surface of humerus superior to radial groove
(short head) posterior surface of humerus inferior to radial groove
I- proximal end of olecranon & fascia of forearm
A- chief extensor of the forearm;
long head resists dislocation of humerus, important in adduction
N- radial nerve (C6, C7, C8)
Anconeus
O- lateral epicondyle of humerus
I- lateral surface of olecranon and superior part of posterior surface of ulna
A- assists triceps in extending forearm; stabilized elbow joint; may abduct the ulna during pronation
N- radial nerve (C7, C8, T1)
Brachioradialis
O- proximal 2./3 of supra-epicondylar ridge of humerus
I- lateral suface of distal end of radius proximal to the styloid process
A- relatively weak flexion of forearm; maximal when forearm is in mid-pronated position
N- radial nerve (C5, C6, C7)
Flexor Carpi Radialis (FCR)
O- medial epicondyle of humerus (common flexor origin)
I- base of 2nd metacarpal
A- flexes & abducts the hand (at the wrist)
N- median nerve (C6 and C7)
Flexor Carpi Ulnaris (FCU)
O- (humeral head) medial epicondyle of humerus (common flexor origin)
(ulnar head) olecranon & posterior border of ulna (via aponeurosis)
I- pisiform, hook of hamate, and 5th metacarpal
A- flexes and adducts hand (at the wrist)
N-
Palmaris Longus
O- medial epicondyle of humerus (common flexor origin)
I- distal half of flexor retinaculum and apex of palmar aponeurosis
A- flexes hand (at wrist) and tenses the palmar aponeurosis
N- median nerve (C7 and C8)
Flexor Digitorum Superficialis
O- (humeroulnar head) medial epicondyle (common flexor origin and coronoid process)
(radial head) superior half of anterior border
I- shafts of middle phalanges of the medial four digits
A- flexes the middle phalanges at the PIP joints of the middle four digits; and acting more strongly also flexes the proximal phalanges at the metacarpal joint
N- median nerve (C7, C8, T1)
Flexor Digitorum Profundus
O- proxmial 3/4 of the medial and anterior surfaces of ulna and interosseous membrane
I- (medial part) bases of distal phalanges of 4th and 5th digits
(lateral part) bases of distal phalanges of 2nd and 3rd digits
A- (medial part) flexes distal phalanges (4 & 5) at DIPs
(lateral part) flexes distal phalanges (2 & 3) at DIPs
N- (medial part) ulnar nerve (C8, T1)
(lateral part) anterior interosseous nerve from the median nerve (C8, T1)
Flexor Pollicis Longus
O- anterior surface of radius & adjacent interosseous membrane
I- base of distal phalanx of thumb
A- flexes phalanges of 1st digit (thumb)
N- anterior interosseous nerve, from median nerve (C8, T1)
Pronator Quadratus
O- distal quarter of anterior surface of ulna
I- distal quarter of anteior surface of radius
A- pronates forearm; deep fibers bind radius and ulna together
N- anterior interosseous nerve, from median nerve (C8, T1)
Supinator
O- lateral epicondyle of humerus
radial collageral and annular ligaments
supinator fossa
crest if ulna
I- lateral, posterior, and anterior surfaces of proximal 1/3 of radius
A- supinates forearm; rotates radius to turn the palm anteriorly or superiorly if the elbow is flexed
N- deep branch of radial nerve (C7, C8)
