Upper Extremity Muscles

Front 1

Frontalis
(facial expression)

Back 1

O - Galea aponeurotica
I - Skin superior to supraorbital line
*A - Draws scalp forward, elevates eyebrows, & wrinkles skin of forehead
*N - Facial nerve (VII)

Front 2

Orbicularis Oris
(facial expression)

Back 2

O - Muscle fibers surrounding opening of mouth
I - Skin at corner of mouth
*A - Closes & shapes lips (i.e., kissing muscle); forms words
*N - Facial nerve (VII)

Front 3

Zygomaticus Major
(facial expression)

Back 3

O - Zygomatic bone
I - Skin at corner of mouth & orbicularis oris
*A - Draws angle of mouth upward as in smiling (smiling muscle)
*N - Facial nerve (VII)

Front 4

Buccinator
(facial expression)

Back 4

O - Alveolar processes of maxilla & mandible
I - Orbicularis oris
*A - Movements of blowing & kissing (blowing muscle)
*N - Facial nerve (VII)
**cheek muscle

Front 5

Risorius
(facial expression)

Back 5

O - Facia over parotid gland
I - Skin at angle of mouth & orbicularis oris
*A - Draws angle of mouth laterally as in grinning or tenseness (grinning muscle)
*N - Facial nerve (VII)

Front 6

Platysma
(facial expression)

Back 6

O - Fascia over deltoideus & pectoralis major muscles
I - Muscles of mandible around angle of mouth & skin of lower face; mandible
*A - Draws lower lip down & backward (pouting); depresses mandible
*N - Facial nerve (VII)

Front 7

Orbicularis Oculi
(facial expression)

Back 7

O - Medial wall of orbit
I - Circular path around orbit
*A - Closes eye lids
*N - Facial nerve (VII)
**sphincteral muscle surrounding muscle

Front 8

Sternocleidomastoid

Back 8

*I - Sternum & clavicle
*O - Mastoid process of temporal bone
*A - Turns head from side to side & flexes head
*N - Spinal accessory nerve (from C3,C4)

Front 9

Masseter
(mastication)

Back 9

O - Maxilla & zygomatic arch
I - Angle and ramus of mandible
*A - Involved in chewing; elevates & protracts mandible
*N - Mandibular branch of trigeminal nerve (V)

Front 10

Temporalis
(mastication)

Back 10

O - Temporal fossa of parietal bone
I - Coronoid process of mandible
*A - Involved in chewing; elevates & retracts mandible
*N - Mandibular branch of trigeminal nerve

Front 11

Medial Pterygoid
(mastication)

Back 11

O - Medial surface of lateral pterygoid lamina of sphenoid
I - Angle & ramus of mandible on medial side of mandible
*A - Involved in chewing; elevates & protracts mandible & moves mandible from side to side
*N - Mandibular branch of trigeminal nerve

Front 12

Lateral Pterygoid
(mastication

Back 12

O - Lateral surface of lateral pterygoid lamina & greater wing of sphenoid
I - Condyle of mandible & temporomandibular articulation
A - Protracts mandible & moves mandible from side to side
N - Mandibular branch of trigeminal nerve

Front 13

Pectoralis Minor
(anterior pectoral girdle)

Back 13

O - Anterior surfaces of 3rd - 5th ribs
I - Coracoid process of scapula
A - Protracts & depresses pectoral girdle
N - (Medial) pectoral nerve

Front 14

Subclavius
(anterior pectoral girdle)

Back 14

O - First rib (anterior surface)
I - Clavicle
A - Depresses clavicle & acts as a dynamic splint
N - Nerve to subclavius (C5,C6)

Front 15

Serratus Anterior
(anterior pectoral girdle)

Back 15

O - Lateral surfaces of 1st - 8th ribs
I - Medial border & inferior angle of scapula
A - Most powerful protractor of pectoral girdle; important fixator of scapula
N - Long thoracic nerve
**Has a jagged-like appearance; "boxer's" muscle; "winged" scapula occurs when serratus anterior is weak

Front 16

Trapezius
(posterior pectoral girdle)

Back 16

O - External occipital protuberance, superior nuchal line, spinous processes of vertebrae C7-T12; ligamentum nuchae attaches to higher cervical vertebrae
I - Acromion end of clavicle, acromion process of scapula, & the spine of the scapula
A - Elevates, retracts, & upwardly rotates pectoral girdle, extends head
- Upper muscles - elevate
- Clavicular head - retracts
- Spinous head - upwardly
rotates
N - Spinal accessory (C3,C4)

Front 17

Rhomboid Major
(posterior pectoral girdle)

Back 17

O - Spinous processes of T2-T5 vertebrae
I - Medial border of scapula
A - Retracts pectoral girdle, rotates scapula downward
N - Dorsal scapular nerve

Front 18

Rhomboid Minor
(posterior pectoral girdle)

Back 18

O - Spinous process of C7-T1 vertebrae
I - Medial border of scapula
A - Retracts pectoral girdle, rotates scapula downward
N - Dorsal scapular
**Only difference w/ rhomboid major is O

Front 19

Levator Scapulae

Back 19

O -
I -
A -
N -

Front 20

Deltoideus

Back 20

O -
I -
A -
N -

Front 21

Supraspinatus
(shoulder joint)

Back 21

O -
I -
A -
N -

Front 22

Infraspinatus
(shoulder joint)

Back 22

O -
I -
A -
N -

Front 23

Subscapularis

Back 23

O -
I -
A -
N -

Front 24

Teres Minor

Back 24

O -
I -
A -
N -

Front 25

Teres Major

Back 25

O -
I -
A -
N -

Front 26

Pectoralis Major

Back 26

O -
I -
A -
N -

Front 27

Latissimus Dorsi

Back 27

O -
I -
A -
N -

Front 28

Biceps Brachii

Back 28

O -
I -
A -
N -

Front 29

Coracobrachialis

Back 29

O -
I -
A -
N -

Front 30

Brachialis

Back 30

O -
I -
A -
N -

Front 31

Triceps Brachii

Back 31

O -
I -
A -
N -

Front 32

Pronator Teres
(anterior/flexor superficial)

Back 32

O -
I -
A -
N -

Front 33

Flexor Carpi Radialis

Back 33

O -
I -
A -
N -

Front 34

Palmaris Longus

Back 34

O -
I -
A -
N -

Front 35

Flexor Digitorum Superficialis

Back 35

O -
I -
A -
N -

Front 36

Flexor Carpi Ulnaris

Back 36

O -
I -
A -
N -

Front 37

Flexor Pollicis Longus
(anterior/flexor deep)

Back 37

O -
I -
A -
N -

Front 38

Flexor Digitorum Profundus

Back 38

O -
I -
A -
N -

Front 39

Pronator Quadratus

Back 39

O -
I -
A -
N -

Front 40

Brachioradialis
(posterior/extensor superficial)

Back 40

O -
I -
A -
N -

Front 41

Extensor Carpi Radialis Longus
(posterior/extensor superficial)

Back 41

O -
I -
A -
N -

Front 42

Extensor Carpi Radialis Brevis

Back 42

O -
I -
A -
N -

Front 43

Extensor Digitorum

Back 43

O -
I -
A -
N -

Front 44

Extensor Digiti Minimi

Back 44

O -
I -
A -
N -

Front 45

Extensor Carpi Ulnaris

Back 45

O -
I -
A -
N -

Front 46

Supinator
(posterior/extensor deep)

Back 46

O -
I -
A -
N -

Front 47

Abductor Pollicis Longus

Back 47

O -
I -
A -
N -

Front 48

Extensor Pollicis Brevis

Back 48

O -
I -
A -
N -

Front 49

Extensor Pollicis Longus

Back 49

O -
I -
A -
N -

Front 50

Extensor Indicis

Back 50

O -
I -
A -
N -