Muscles of the Shoulder, Elbow, Wrist and Hand Flashcards
Deltoid
All fibers: abduct shoulder
Anterior fibers: flex, IR and horizontally adduct the shoulder
Posterior fibers: extend, ER, and horizontally abduct the shoulder
O: lateral 1/3 of clavicle, acromion and spine of scapula
I: deltoid tuberosity
Axillary Nerve
C5, 6
Trapezius
Upper fibers:
- Bilaterally extend head and neck
- Unilaterally: laterally flex to the SAME side, rotate to the OPPOSITE side, elevate and upwardly rotate the scapula
Middle Fibers: adduct and stabilize the scapula
Lower Fibers: depress and upwardly rotate the scapula
O: external occipital protuberance, medial portion of superior nuchal line of the occiput, ligaments niche and SP of C7-T12
I: lateral 1/3 of clavicle, acromion and spine of scapula
Spinal portion of CN XI (accessory) and ventral ramus C2-4
Latissimus Dorsi
Extends, IR and adducts the shoulder
O: inferior angle of scapula, SP of T6-12, ribs 8-12, thoracolumbar aponeurosis and posterior iliac crest
I: Intertuberuclar groove of the humerus
Thoracodorsal Nerve
C6-8
Teres Major
Extends, adducts and IR the shoulder
O: inferior angle and lower 1/3 of lateral border of scapula
I: crest of the lesser tubercle of the humerus
Lower sub scapular nerve
C5-7
Supraspinatus
Abducts the shoulder
Stabilizes the humeral head in the glenoid cavity
O: supraspinatus fossa of the scapula
I: Greater tubercle
Suprascapular Nerve
C5-6
Infraspinatus
ER and abducts the shoulder
Stabilizes the humeral head
O: Infraspinatus fossa
I: greater tubercle
Suprascapular Nerve
C5-6
Teres Minor
ER and adduct the shoulder
Stabilizes the humeral head
O: upper 2/3 of lateral border of scapula
I: greater tubercle
Axillary Nerve
C5-6
Subscapularis
IR shoulder
O: subscapular fossa
I: lesser tubercle
Upper and lower sub scapular nerve
C5-6
Rhomboids
Adduct, elevate and downwardly rotate the scapula
Major O:SP T2-5
Major I: medial border of the scapula between scapula spine and inferior angle
Minor O: SP of C7-T1
Minor I: upper portion of the medial border of the scapula, across from spine of scapula
Dorsal scapular nerve
C4-5
Levator scapula
Bilaterally: extends the neck
Unilaterally: laterally flexes neck and rotates to the same side; elevates and downwardly rotates scapula
O: TP of C1-4
I: medial border of scapula between superior angle and superior portion of spine of scapula
C3,4 and Dorsal scapular nerve
C3-4
Serratus Anterior
With the origin fixed:
Abducts, upwardly rotates and depresses the scapula
Holds medial border of scapula against rib cage
With the scapula fixed: may act to elevate the thorax during forced inhalation
O: external surfaces of ribs 1-9
I: anterior surface of medial border of scapula
Long thoracic nerve
C5-7
Pectoralis Major
All fibers: adduct and IR the shoulder; assist to elevate the thorax during forced inhalation (with the arm fixed)
Upper fibers (clavicular portion): flex and horizontally adduct the shoulder
Lower fibers (sternocostal portion): extend the shoulder
Clavicular portion O: medial half of clavicle, Sternocostal portion O: sternum and cartilage of ribs 1-6
I: crest of greater tubercle
Upper fibers: lateral pectoral nerve C5-7
Lower fibers: lateral and medial pectoral nerve C6-T1
Pectoralis Minor
Scapular depression, protraction and downward rotation
With the scapula fixed, assists to elevate the thorax during forced inhalation
O: ribs 3-5
I: Medial surface of coracoid process of the scapula
Medial pectoral nerve C8-T1
Biceps Brachii
Shoulder flexion
Elbow flexion
Supination
Long head O: supraglenoid tubercle of scapula (tendon passes through the inter tubercular groove of the humerus)
Short head O: coracoid process of scapula
I: Radial tuberosity and aponeurosis of the biceps
Musculocutaneous nerve (C5, 6)
Triceps
All: extend the elbow (humeroulnar joint)
Long head: extends and adducts the shoulder
Long head O: infraglenoid tubercle
Lateral head O: posterior surface of proximal half of the humerus
Medial head O: posterior surface of distal half of the humerus
I: olecranon process of the ulna
Radial nerve C6-T1
Coracobrachialis
“armpit muscle”; deep to the pec major and ant deltoid and lies anterior to the axillary artery and brachial plexus
secondary flexor and adductor of the shoulder
O: coracoid process of the scapula
I: medial surface of mid humeral shaft
Musculocutaneous nerve C6-7
Brachialis
strong elbow flexor
lies deep to biceps brachii
O: distal half of anterior surface of humerus
I: ulnar tuberosity and coronoid process
Musculocutaneous C5-7
Brachioradialis
Flexes the elbow
Assists to pronate and supinate the forearm when these movements are resisted
O: proximal 2/3 of the lateral supracondylar ridge of the humerus
I: styloid process of the radius
Radial nerve C5-6
Extensor carpi radialis longus and brevis
Extend and abduct the wrist
Assist to flex the elbow
Longus
O: distal 1/3 of lateral supracondylar ridge of humerus
I: base of 2nd metacarpal
Radial nerve C6-7
Brevis
O: common extensor tendon from the lateral epicondyle of humerus
I: base of 3rd metacarpal
Posterior interposes off radial nerve C7-8
Extensor carpi ulnaris
Extends and adducts the wrist
O: common extensor tendon from the lateral epicondyle of the humerus
I: base of 5th metacarpal
Posterior interosseus off the Radial nerve C7-8
Extensor digitorum
extends fingers 2-5 (MCP and IP joints)
Assists to extend the wrist
O: common extensor tendon from the lateral epicondyle of the humerus
I: bases of middle and distal phalanges of fingers 2-5
Posterior interosseus (radial) C7-8
Anconeus
weak elbow extensor
O: lateral epicondyle of humerus
I: olecranon process and posterior, proximal surface of ulna
Radial nerve C7-T1
Extensor Indicis
Extends and adducts the 2nd finger
May assist with wrist extension
O: posterior surface of distal shaft of ulna and interosseous membrane
I: tendon of the extensor digitorum at the level of the 2nd metacarpal
Posterior interossei (radial) C7-8
Flexor carpi radialis
Flexes and abducts the wrist
May help to flex the elbow
O: common flexor tendon from medial epicondyle
I: bases of 2nd and 3rd metacarpals
Median nerve C6-7
