Muscles Of The Upper Extremity

Front 1

Pectoralis Minor

Back 1

O: 3rd-5th Ribs.
I: Coracoid process of scapula.
N: Medial pectoral nerve.
A: Assists serratus anterior, draws scapula near chest wall (protraction). Medial downward rotation of scapula.

Front 2

Subclavius
{Not responsible for O, I, or A}

Back 2

N: Nerve to the subclavius

Front 3

Serratus Anterior

Back 3

O: Ribs 1-8 or 9.
I: Anterior surface of medial border of scapula. (Quite large insertion).
N: Long thoracic nerve.
A: 1) fibers @ inferior angle- lateral upward rotation of scapula. 2) W/ pectoralis minor protracts scapula (draws forward).

Front 4

Trapezius Muscle
[Upper Fibers]

Back 4

O: Superior Nuchal Line & External Occipital Protuberance
I: Posterior surface of lateral 1/3 of clavicle
N: Accessory Nerve (IX) & Branches of Cervical Plexus
A: Act w/ Levator Scapulae and elevate scapula & pt of shoulder. Flex head & neck laterally

Front 5

Deltoid

Back 5

O: Lateral 1/3 of clavicle.
I: Deltoid tuberosity.
N: Axillary nerve.
A: Strong adductor of arm, but is incapable of initiating the movement.

Front 6

Trapezius Muscle
[Middle Fibers]

Back 6

O: Ligamentum Nuchae & Spiones of the C7, upper thoracic vertebrae and corresponding supraspinous ligaments
I: Medial border the acromial process
N: Accessory nerve XI and branches of cervical plexus.
A: Assist rhomboids to retract scapula.

Front 7

Trapezius Muscle
[Lower Fibers]

Back 7

O: Spinous process of lower thoracic vertebrae and corresponding supraspinous ligaments.
N: Accessory nerve XI & branches of cervical plexus.
A: Depress the scapula

Front 8

Supraspinatus

Back 8

O: supraspinatous fossa.
I: Greater tubercle of humerus.
N: Suprascapular nerve.
A: Initiator of abduction of the arm.

Front 9

Latissimus Dorsi

Back 9

O: Spines of lower six thoracic vertebrae, thoracolumbar fascia, spines of lumbar & sacral vertebrae & supraspinous ligaments, & crest of illium.
I: Intertubercular sulcus.
N: Thoracodorsal nerve.
A: Adduction, Extension, & medial rotation of humerous. Also pulls trunk upwards & forward.

Front 10

Rhomboideus Minor

Back 10

O: Lower part of Ligamentum Nuchae & spines of C7 & T1.
I: Vertebral margin of scapula at medial end of spine.
N: Dorsal Scapular Nerve.
A: Retraction & slight elevation of scapula.

Front 11

Infraspinatus

Back 11

O: Infraspinous fossa.
I: Greater tubercle of humerus.
N: Suprascapular nerve.
A: Extension & Lateral rotation of arm.

Front 12

Rhomboideus Major

Back 12

O: Spinous process & corresponding supraspinous ligament of T2-T5.
I: Vertebral margin of scapula below medial end of spine.
N: Dorsal Scapular Nerve.
A: Draws scapula toward vertebral column (retraction).

Front 13

Levator Scapulae

Back 13

O: Transverse process of Axis & Atlas and Transverse process of C3 & C4.
I: Superior Angle & Upper part of vertebral border of scapula.
N: Cervical plexus & Dorsal Scapular Nerve.
A: Elevation of scapula.

Front 14

Pectoralis Major
[Sternocostal Head]

Back 14

O: Manubrium and body of the sternum from rib cartilages 1-6.
I: Crest of greater tubercle of the Humerus.
N: The Lateral & Medial Pectorial nerves.
A: Adducts, Flexes, and Medially rotates the arm. Draws body upward & forward during climbing.

Front 15

Pectoralis Major
[Clavicular Head]

Back 15

O: Anterior border of medial half of the claivicle.
I: Crest of greater tubercle of the Humerus.
N: The Lateral & Medial Pectorial nerves.
A: Adducts, Flexes, and Medially rotates the arm. Draws body upward & forward during climbing.

Front 16

Subscapularis

Back 16

O: Subscapular fossa.
I: Lesser tubercle of humerus.
N: Upper & Lower subscapular nerves.
A: Medial rotation of the arm.

Front 17

Teres Minor

Back 17

O: Axillary border of scapula.
I: Greater tubercle of humerus.
N: Axillary nerve.
A: Adduction & lateral rotation of the arm.

Front 18

Teres Major

Back 18

O: Inferior angle of scapula.
I: Crest of lesser tubercle of the humerus.
N: Lower subscapular nerve.
A: Adduction, extension, and medial rotation of the arm.

Front 19

Coracobrachialis

Back 19

O: Coracoid process of the scapula.
I: An impression, midway along the medial border of the shaft of the humerus.
N: Musculocutaneous nerve.
A: Flexion & adduction of the arm.

Front 20

Brachialis

Back 20

O: Lower anterior 1/2 of humerus.
I: Tuberosity of ulna & coronoid process of ulna.
N: Musculocutaneous nerve.
A: Flexor of the elbow.

Front 21

Biceps Brachii
[Short Head]

Back 21

O: Coracoid process of scapula.
I: Radial tuberosity of radius, Bicipital aponeurosis.
N: Musculocutaneous nerve.
A: Flexor of the elbow.

Front 22

Biceps Brachii
[Long Head]

Back 22

O: Supraglenoid tubercle of the scapula.
I: Radial tuberosity of radius, Bicipital aponeurosis.
N: Musculocutaneous nerve.
A: Flexor of the elbow.

Front 23

Triceps Brachii
[Long Head]

Back 23

O: Infraglenoid tubercle of the scapula, between teres minor and major muscles.
I: Olecranon process.
N: Radial nerve (separate branch for each head.)
A: Extension of elbow & Supports the arm.

Front 24

Triceps Brachii
[Lateral Head]

Back 24

O: Posterolateral surface of the humerus.
I: Olecranon process.
N: Radial nerve (separate branch for each head.)
A: Extension of elbow.

Front 25

Triceps Brachii
[Medial Head]

Back 25

O: Posteromedial surface of the humerus, below the radial groove.
I: Olecranon process.
N: Radial nerve (separate branch for each head.)
A: Extension of elbow.

Front 26

Pronator Teres

Back 26

O: [Humeral Head]- medial epidcondyle of humerus above common flexor tendon.
O: [Ulnar Head]- medial side of coronoid process.
I: Lateral surface of middle 1/3 of radius.
N: Median Nerve
A: Rotates the radius on the ulna to pronate the hand. Weak flexor of elbow.

Front 27

Palmaris Longus

Back 27

O: Medial epicondyle of the humerus by common flexor tendon.
I: Anterior surface od distal 1/2 and central region of the palmar aponeurosis.
N: Median nerve.
A: Weakly flexes the wrist.

Front 28

Flexor Carpi Radialis

Back 28

O: Medial epicondyle of the humerus by the common flexor tendon.
I: Palmar surface of the base of 2nd metacarpal bone.
N: Median nerve.
A: Flexes wrist (acting w/ flexor muscles). Abducts the hand (acting w/ radial extensors).

Front 29

Flexor Digitorum Superficialis

Back 29

O: [Humeroulnar Head]- medial epidondyle of the humerus & medial side of coronoid process.
O: [Radial Head]- Anterior surface of the proximal radius.
I: Shaft of the middle phalanx of fingers 2-5.
N: Median nerve.
A: flexes the middle phalanx, then proximal phalanx, then wrist.

Front 30

Flexor Carpi Ulnaris

Back 30

O: [Humeral Head]- medial epicondyle of the humerus.
O: [Ulnar Head]- Medial region of the olecranon & upper 2/3's of posterior border of the ulna.
I: Pisiform bone, Hamate bone, and 5th metacarpal bone.
N: Ulnar nerve.
A: Flexes wrist (w/ flexor muscles). Abducts hand (w/ Extensor carpi ulnaris).

Front 31

Pronator Quadratus

Back 31

O: Distal 1/4 of anterior surface of the shaft of the ulna.
I: Distal 1/4 of anterior surface of the shaft of the radius.
N: Anterior interosseous branch of median nerve.
A: Primary pronator of forearm.

Front 32

Flexor Pollicis Longus

Back 32

O: Anterior surface of the radius & adjacent interosseous membrane.
I: Base of distal phalanx of the thumb.
N: Anterior interosseous branch of the median nerve.
A: Flexes phalanges of the thumb.

Front 33

Flexor Digitorum Profundus

Back 33

O: Upper 3/4's of the anterior & medial surfaces of the ulna & adjacent ulnar half of the interosseous membrane.
I: Bases of distal phalanges 2-5.
N: Ulnar half by the ulnar nerve & radial half by the anterior interosseous nerve branch of the median nerve.
A: Flexes distal phalanges first, middle phalanges second, proximal phalanges, and then the wrist.

Front 34

Anconeus

Back 34

O: Lateral epicondyle of humerus.
I: Olecranon & upper 1/4 of the posterior surface of ulna.
N: Radial nerve.
A: Extends forearm, abducts ulna during pronation of wrist.

Front 35

Brachioradialis

Back 35

O: Upper 2/3's of lateral supracondylar ridge of humerus.
I: Lower end of radius.
N: Radial nerve.
A: Flexor of the elbow.

Front 36

Extensor Carpi Radialis Longus

Back 36

O: Lower 1/3 os lateral supracondylar ridge of humerus.
I: Base of the 2nd metacarpal bone.
N: Radial nerve.
A: Synergistic movements. W/ extensor carpi ulnaris = extend wrist. W/ flexor carpi radialis = anduct wrist.

Front 37

Extensor Carpi Radialis Brevis

Back 37

O: Common extensor tendon.
I: Base of 3rd metacarpal bone.
N: Posterior interosseous nerve.
A: Synergistic movements. W/ extensor carpi ulnaris = extend wrist. W/ flexor carpi radialis = anduct wrist.

Front 38

Extensor Digitorum

Back 38

O: Common extensor tendon.
I: Interosseous connexions, Dorsal digital expansion, & insert into proximal, middle, and distal phalanges.
A: Extends fingers 2-5.

Front 39

Extensor Digiti Minimi

Back 39

O: Common extensor tendon.
I: Dorsal extensor aponeurosis of 5th digit.
N: Posterior interosseous nerve.
A: Extends little finger & wrist.

Front 40

Extensor Carpi Ulnaris

Back 40

O: Common extensor tendon & posterior border of the upper 2/3's of the ulna.
I: Base of the 5th metacarpal.
N: Posterior interosseous nerve.
A: Acts syngergistically. Extends the wrist. Adducts the wrist.

Front 41

Supinator

Back 41

O: Supinator crest of ulna & triangular depression in front of supinator crest.
I: Proximal 1/3 of radius.
N: Posterior interosseous membrane.
A: Acts in supination.

Front 42

Abductor Pollicis Longus

Back 42

O: Posterior surface of the shaft of the ulna. Interosseous membrane. Posterior surface of the radius.
I: Base of 1st metacarpal.
N: Posterior interosseous nerve.
A: Abducts & extends thumb.

Front 43

Extensor Pollicis Brevis

Back 43

O: Posterior surface of the radius & interosseous membrane.
I: Base of proximal phalanx of thumb
N: Posterior interosseous nerve.
A: Extends proximal phalanx of thumb.

Front 44

Extensor Pollicis Longus

Back 44

O: Middle 1/3 of the posterior surface of the shaft of the ulna.
I: Base of distal phalanx of the thumb.
N: Posterior interosseous nerve.
A: Extends distal phalanx of the thumb.

Front 45

Extensor Indicis

Back 45

O: Posterior surface of the ulna & interosseous membrane.
I: Dorsal extensor aponeurosis of 2nd digit.
N: Posterior interosseous nerve.
A: Extends 2nd (index) finger.

Front 46

Abductor Pollicis Brevis

Back 46

O: Flexor Retinaculum.
I: Base of proximal phalanx of the thumb.
N: Recurrent branch of lateral terminal branch of median nerve.
A: Abducts thumb.

Front 47

Opponens Pollicis

Back 47

O: Flexor retinaculum.
I: Metacarpal bone of the thumb.
N: Recurrent branch of the lateral terminal branch of the median nerve.
A: Flexes the 1st metacarpal bone & rotates it medially. (movement = opposition).

Front 48

Flexor Pollicis Brevis

Back 48

O: Felxor Retinaculum.
I: Base of proximal phalanx of the thumb.
N: Recurrent branch of the lateral terminal branch of the median nerve & deep terminal branch of the ulnar nerve.
A: Flexes proximal phalanx of the thumb.

Front 49

Adductor Pollicis

Back 49

O: [Oblique Head]- Capitate bone & 2nd & 3rd metacarpal bones.
O: [Tranverse Head]- 3rd metacarpal.
I: Base of the proximal phalanx of the thumb.
N: Deep terminal branch of the ulnar nerve.
A: Approximates the thumb.

Front 50

Palmaris Brevis

Back 50

O: Flexor retinaculum.
I: Dermis on the ulnar border of the hand.
N: Superficial terminal branch of the ulnar nerve.
A: Wrinkles skin on ulnar side of hand & contributes to palmar grip.

Front 51

Abductor Digiti Minimi

Back 51

O: Pisiform bone.
I: Base of proximal phalanx of the little finger.
N: Deep terminal branch of the ulnar nerve.
A: Abducts little finger.

Front 52

Flexor Digiti Minimi (Brevis)

Back 52

O: Hook of hamate bone & flexor retinaculum.
I: Base of proximal phalanx of the little finger.
N: Deep terminal branch of the ulnar nerve.
A: Flexes little finger.

Front 53

Opponens Digiti Minimi

Back 53

O: Hook of hamate bone & flexor retinaculum.
I: Ulnar side of 5th metacarpal.
N: Deep terminal branch of the ulnar nerve.
A: Draws 5th metacarpal forward & rotates laterally. (movement = opposition).

Front 54

Lumbricals
(#1 - #4)

Back 54

O: 1st- Radial/palmar side of FDP to 2nd finger.
2nd- Radial/palmar side of FDP to 3rd finger.
3rd- adjacent sides of FDP to 3rd & 4th fingers.
4th- Adjacent sides of FDP to 4th & 5th fingers.
I: Radial side of the extensor aponeurosis of the next (higher #) finger.
N: 1st & 2nd- Median nerve.
3rd & 4th- Deep terminal branch of the ulnar nerve.
A: Flex metacarpophalangeal joints.

Front 55

Dorsal Interossei
(#1 - #4)

Back 55

O: From Ulnar side of metacarpal # and radial side of metacarpal (#+1).
I: Base of proximal phalanx and into dorsal digital expansion on radial side of index and middle fingers & ulnar side of middle and ring fingers.
N: Deep terminal branch of the ulnar nerve.
A: Abduct fingers 2-4.

Front 56

Palmar Interossei
(#1 - #4)

Back 56

O: 1&2- From entire ulnar side of the # metacarpal.
3&4- From entire radial side of the (#+1) metacarpal.
I: 1&2- Ulnar side of the extensor aponeurosis of # digit.
3&4- Radial side of the extensor aponeurosis of (#+1) digit.
N: Deep terminal branch of the ulnar nerve.
A: Adduct fingers 1,2,4, & 5 to the axis of the hand.