deck 1, nerves and actions shoulder Flashcards
unilateral action of superior fibers of trapezius
Elevation and upper rotation of the scapula; ipsilateral side bending (laterally flex) and contralateral rotation of the head
bilateral action of superior fibers of trapezius
Bilaterally: extend the head and neck
action of the middle fibers of trapezius
retraction of scapula, adduct and stablize scap
action of inferior fibers of trapezius
depression of the scapula, upwardly rotate scapula
all three parts of the trapezius are innervated by
CN XI (accessory nerve) C3, C4
action of rhomboid major
elevates and retracts the scapula, adducts the scapula, downwardly rotates scapula
action of rhomboid minor
Elevates and retracts the scapula, adduct the scapula, downwardly rotate the scapula
rhomboid minor and major are innervated by
dorsal scapular nerve (c4-c5)
action of the levator scapulae
elevates the scapula, ipsilaterally side bending and rotation of the head, downwardly rotate the scapulaBilaterally: extend the head and neck
innervation of the levator scapulae
anterior rami of c3 and c4 spinal nerves and by c5 brances of dorsal scapular nerve
latissimus dorsi actions:
adduction, medial rotation and extension of the arm at the glenohumeral joint
innervation of latissimus dorsi
thoracodorsal nerve c6, c7,c8
teres major action
medial rotation, extension of the arm and adduction of the glenohumeral joint
innervation of teres major
lower subscapular nerve c5, c6
deltoid, posterior action
abbduct, extension, horizontal abduction and external rotation of the humerus
deltoid middle fibers action
abduction of humerus
deltoid anterior fibers, action
abduct, flexion, horizontal adduction, internal rotation of the humerus
innervation of all deltoid parts
Axillary, C5, C6
action of pectoralis major:
A: All fibers: flexion, adduction of glenohumeral (GH) joint, and medial rotation of glenohmeral joint; assist to elevate the thorax during forced inhalation with arm fixed; Clavicular head: flexion of the extended shoulder horizontal adduction of GH joint;Sternocostal head: extension of the flexed shoulder
action of pectoralis minor
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
innervation of pectoralis major:
Medial and lateral pectoral nerves (C5-T1)Clavicular head: lateral pectoral (C5, C6)Sternocostal head: lateral and medial pectoral nerves (C7, C8, T1)
innervation of pectoralis minor
Medial pectoral nerve (C8, T1) (some with fibers from the communicating branch of the lateral pectoral nerve C6, C7,C8,T1)
subclavius action:
anchors and stablized the sternoclavicular joint, depresses and draws the clavicle anteriorly, elevates the first rib (inhale)
innervation of sublcavius:
subclavian nerve, C5, C6
serratus anterior: action, fixed origin
abduct/protraction of the scapula, upwardly rotat the scapula, depresses the scap, hold the medial and inferior borders of the scapula against the rib cage
serratus anterior action, with scap fixed
elevate the thorax during forced inhalation
serratus anterior, innervation
long thoracic nerve, C5, C6, C7
action of the coracobrachialis
flexor and aDD of the arm at the glenohumeral joint
innervation of the coracobrachialis
musculocutaneous nerve C5, C6, c7
Action of the infraspinatus (rotator cuff muscle)
assists with maintaining gh sstability, lateral rotation of the arm at gh, aDD of the shoulder at GH
innervation of the infraspinatus
suprascapular nerve (C5, C6)
action of the teres minor
rotator cuff: lateral (ext) rot of gh, aDD shoulder at GH, stablize GH
innervation of the teres minor:
axillary nerve, C5, c6
subscapularis innervation
upper and lower subscapular nervs c5 C6 c7
action of brachialis
flexion of the forearm at elbow in al positions
subscapularis action
rotator cuff muscle: assist with gh stability, medial rotation of shoulder at gh
action of the bicepc
flexion of the forearm at the lebow joint and supination of the arm at the gh, accessory flexor of the arm at the gh
innervation of biceps brachii
musculocutaneous c5 C6
innervation of brachialis
musculocutaneous c5 C6
innervation of the triceps brachii
radial nerve (c6, C7, C8
action of triceps brachii:
extention of the forearm at elbow joint, long head: extend + ADD at gh