Muscles of Upper Limb Flashcards
Pectoralis Major
O: anterior/medial clavicle, sternum, superior 6 costal cartilages, external oblique aponeurosis
I: Intertubercular groove of humerous
A: ADduction & medial rotate arm
Clavicular portion flexus humerous
Sternocostal portion extends from flexed position
N: medial and lateral pectoral nerve (mostly lateral)
B: Pectoral branch of thoracoacromial trunk
Pectoralis Minor
O: Ribs 3-5 near costal cartilage
I: Medial/Superior coracoid process of scapula
A: stabilizes scapula against thoracic cage, elevates ribs when scapula is fixed (accessory m. of resp)
N: medial pectoral nerve (some contribution from lateral)
B: Thoracoacromial trunk (pectoral branch)
Subclavius
O: junction of 1st rib and manubrium
I: inferior center of the clavicle
A: anchors and depresses the clavicle
N: Nerve to the subclavius
Serratus Anterior
O: Lateral parts of ribs 1-8
I: medial/anterior border of scapula
A: protracts/stabilizes scapula, lower fibers rotate scapula
Main muscle that holds scapula down onto ribcage
N: Long Thoracic Nerve
Note: most motor nerves to muscles pass deep to them. The long thoracic nerve to serratus anterior is superficial!
Damage to what nerve/muscle results in a winged scapula?
Damage to The Long Thoracic Nerve - innervates Serratus Anterior. Have pt push against wall, serratus anterior can’t hold scapula back so it pops up. Pt can’t abduct arm above 90 degrees.
Trapezius
O: occiput, spinous processes of C1-T12
I: Lateral 1/3 of clavicle, acromion, superior border of scapular spine
A: elevates, retracts, rotates, depresses scapula
N: CN XI (accessory nerve)
Levator Scapulae
O: Transverse Processes C1-C4
I: superior angle of scapula
A: elevates scapula
N: dorsal scapular nerve
Rhomboid Minor
O: spinous processes C6-7
I: medial border of scapula above scapular spine
A: retracts and elevates scapula
N: dorsal scapular nerve
Rhomboid Major
O: spinous processes T1-4
I: medial border of scapula below scapular line
A: retracts and elevates scapula
N: dorsal scapular nerve
Latissimus Dorsi
O: spinous processes T7-12, thoracolumbar fascia, iliac crest
I: floor of intertubercular groove of huerous
A: ADduct, extend, medially rotate humerous
“pull-up muscle”
N: thoracodorsal nerve
Deltoid
O: lateral third of clavicle, acromion, and scapular spine
I: deltoid tuberosity of humerus
A: anterior part flexes & medially rotates arm, middle part abducts the arm, posterior part extends & laterally rotates arm
N: axillary nerve
Teres Major
O: posterior surface of inferior angle of scapula
I: medial lip of the intertubercular groove of humerus
A: adduction and medial rotation of arm (mini lat dorsi)
N: lower subscapular nerve
Part of Rotator Cuff
Which muscles make up the rotator cuff?
“SITS”
Supraspinatous: suprascapular nerve
Infraspinatous: suprascapular nerve
Teres Minor: axillary nerve
Subscapularis: upper & lower subscapular nerve
Supraspinatous
O: supraspinous fossa of scapula
I: superior aspect of the greater tubercle of the humerus
A: initiates abduction, stabilization of glenohumeral-jt
N: suprascapular nerve
Infraspinatous
O: infraspinatus fossa of the scapula
I: greater tubercle of the humerus
A: lateral rotation, stabilizatoin of glenohumeral-jt
N: suprascapular nerve
Teres Minor
O: lateral border of scapula
I: greater tubercle of humerus
A: lateral rotation, stabilization of glenohumeral-jt
N: axillary nerve
Subscapularis
O: subscapular fossa
I: lesser tubercle of humerus
A: medial rotation, stabilization of glenohumeral-jt
N: upper and lower subscapular nerves
Biceps Brachii
Anterior Compartment of Arm
A: flexes arm/forearm & supinates forearm
N: musculocutaneous nerve
B: brachial artery & branches
Long head: O: supraglenoid tubercle of scapula
Short head: O: coracoid process of scapula
I: radial tuberosity (both long & short heads)
Brachialis
Anterior Compartment of Arm O: distal half of anterior surface of humerus I: coronoid process and ulnar tuberosity A: main flexor of arm N: musculocutaneous AND radial nerves B: brachial artery & branches
Coracobrachialis
Anterior Compartment of Arm
O: coracoid process of scapula
I: middle 1/3 of medial surface of humerus
A: flexor/adductor of arm, prevents anterior dislocation
N: musculocutaneous nerve
B: brachial artery & branches
Triceps Brachii
Long Head
Lateral Head
Medial Head
Posterior Compartment of Arm
Long Head - O: Infraglenoid tubercle of scapula
Lateral Head:
O: Post surface of humerus, superior to radial groove
Medial Head
O: Posterior surface of humerus, inferior to radial groove
I: Prox end of olecranon of ulna & fascia of forearm
A: Extend forearm
N: radial nerve
B: brachial artery & branches
Anconeus
Posterior Compartment of Arm
O: lateral epicondyle of humerus
I: Lateral surface of olecranon & superior part of posterior surface of ulna
A: Assists triceps in extending forearm, stabilizes elbow joint, abducts ulna during pronation
N: radial nerve
B: brachial artery & branches
Pronator Teres
(humeral head) (superficial) (Superficial Group)
(ulnar head) (deep) (Intermediate Group)
O: (humeral head) medial epicondyle of humerus O: (ulnar head) proximal ulna I: lateral midshaft of radius A: pronation N: median nerve
Palmaris Longus
O: medial epicondyle of humerus
I: palmar aponeurosis
A: flex wrist, tense palmar aponeurosis
N: median nerve
Flexor Carpi Radialis
O: medial epicondyle of humerus
I: palmar base of MC II
A: flex/abduct wrist
N: median nerve
Flexor Carpi Ulnaris
O: medial epicondyle of humerus & olecranon process
I : hook of hamate, pisiform, palmar base of MC V
A: flex/adduct wrist
N: ulnar nerve
Flexor Digitorum Superficialis
O: medial epicondyle of humerus & prox radius
I: base of intermediate phalanges of digits 2-5
A: flex PIP, MCP, wrist
N: median nerve
Flexor Digitorum Profundus
O: Ulnar shaft, interosseous membrane
I: Base of distal phalanges of digits 2-5
A: flex DIP, PIP, MCP, IP of digit 1, wrist
N: Anterior Interoseous Nerve (medial 1/2)
Ulnar Nerve (lateral 1/2)
Brachioradialis
Posterior Compartment of Forearm
O: lateral supracondylar ridge of humerus
I: styloid process of radius
N: radial nerve
A: EXCEPTION!! flexion of forearm “hammer curls”
Extensor Carpi Radialis Longus
Posterior Compartment of Forearm O: lateral supracondylar ridge of humerus I: dorsal base of MC II N: radial nerve A: extends and abducts wrist
Extensor Carpi Radialis Brevis
Posterior Compartment of Forearm O: lateral epicondyle of humerus I: dorsal base of MC III N: deep branch of radial n A: extends and abducts wrist
Extensor Carpi Ulnaris
Posterior Compartment of Forearm O: lateral epicondyle of humerus I: dorsal base of MC 5 N: deep branch of radial n. A: extends and adducts wrist
Extensor Digitorum
Posterior Compartment of Forearm O: lateral epicondyle of humerus I: extensor expansion of digits 2–5 N: deep branch of radial n. A: extends digits 2–5 at all joints & extends wrist
Extensor Digiti Minimi
Posterior Compartment of Forearm O: lateral epicondyle of humerus I: extensor expansion of digit 5 N: deep branch of radial n. A: extends digit 5 at all joints, extends & adducts wrist
Supinator
Posterior Compartment of Forearm (deep group)
O: lateral epicondyle humerus; post. olecranon process
I: proximo-lateral radius
N: deep branch of radial n.
A: supinates forearm
Abductor Pollicis Longus
Posterior Compartment of Forearm (deep group)
O: posterior ulna, radius, interosseous membrane
I: base of MC I
N: posterior interosseous n. (terminal branch of the deep branch of the radial n.\
A: abducts pollex (thumb)
Extensor Pollicis Longus
Posterior Compartment of FOrearm (deep group) O: posterior ulna, interosseous membrane I: base of distal phalanx of pollex N: posterior interosseous n. A: extends pollex (thumb) at all joints
Extensor Pollicis Brevis
Posterior Compartment of Forearm (deep group)
O: posterior radius, interosseous membrane
I: base of proximal phalanx of pollex
N: posterior interosseous n.
A: extends pollex at MCP joint
Extensor Indicis
Posterior Compartment of Forearm (deep group)
O: posterior ulna, interosseous membrane
I: extensor expansion of digit 2
N: posterior interosseous n.
A: extends digit 2 at all jts, extends wrist
