Muscle
Innervation
Action
Anterior Thigh
Quadriceps Femoris:
Femoral (L2-4)
Extends Leg
Rectus Femoris
Vastus Medialis
Vastus Lateralis
Vastus Intermedius
Articularis Genu
Femoral
Sartorius
Femoral
"Flexes, Abducts, and Laterally Rotates Thigh"
Flexes and Medially Rotates Leg at Knee
Medial Thigh
Pectineus
Femoral and Obturator
"Flexes, adducts, medially rotates hip joint"
Adductor longus
Obturator (L2-4)
Adducts thigh and flexes hip joint
Adductor brevis
Obturator
Adducts thigh and flexes hip joint
Gracilis
Obturator
Adducts thigh and flexes knee joint
Adductor magnus
Obturator
Adducts thigh; Flexes and Extends Hip Joint
Posterior Thigh
Biceps Femoris
Sciatic
flexes leg and long head also extends thigh
Semitendinosus
Sciatic
flexes leg and extends thigh
Semimembranosus
Sciatic
flexes leg and extends thigh
Gluteal Region
Gluteus Maximus
Inferior Gluteal (L5-S2)
extends and laterally rotates thight
Gluteus Medius
Superior Gluteal (L4-S1)
abducts and medially rotates thigh
Gluteus Minimus
Superior Gluteal (L4-S1)
abducts and medially rotates thigh
Tensor Fasciae Latae
Superior Gluteal (L4-S1)
tenses iliotibial tract
Piriformis
"Nerve to Piriformis (S1,S2)"
laterally rotates thigh
Superior/Inferior Gemellus
"Nerve to Obturator Internus (L5,S1)"
laterally rotates thigh
Quadratus Femoris
"Nerve to Quadratus Femoris (L5,S1)"
laterally rotates thigh
Muscle
Innervation
Action
Anterior Leg
Tibialis Anterior
"Deep Fibular (L4,L5)"
dorsiflexes and inverts foot
Extensor Hallicus Longus
"Deep Fibular (L4,L5)"
extends big toe
Extensor Digitorum Longus
"Deep Fibular (L4,L5)"
extends toes 2-5
Fibularis Tertius
"Deep Fibular (L4,L5)"
dorsiflexes and everts foot
Lateral Leg
Fibularis Longus
Superficial Fibular
everts foot
Fibularis Brevis
Superficial Fibular
everts foot
Posterior Leg
(Superficial)
Gastrocnemius
"Tibial Nerve (S1,S2)"
plantarflexes foot and flexes knee if foot not fixed
Soleus
"Tibial Nerve (S1,S2)"
plantarflexes foot
Plantaris
"Tibial Nerve (S1,S2)"
assists in plantarflexion
(Deep)
Popliteus
Tibial Nerve
internally rotates tibia on femur (unlocks knee)
Tibialis Posterior
Tibial Nerve
plantarflexes and adducts foot
Flexor Hallucis Longus
Tibial Nerve
flexes big toe
Flexor Digitorum Longus
Tibial Nerve
flexes toes 2-5
Dorsum of Foot
Externsor Hallucis Brevis
Deep Fibular
helps extend big toe
Externor Digitorum Brevis
Deep Fibular
helps extend toes 2-5
Sole of Foot
(1st layer)
Abductor Hallucis
Medial Plantar Nerve
abducts and flexes big toe
Flexor Digitorum Brevis
Medial Plantar Nerve
flexes toes 2-5
Abductor Digiti Minimi
Lateral Plantar Nerve
abducts and flexes little toe
Muscle
Innervation
Action
(2nd layer)
Quadratus Plantae
Lateral Plantar Nerve
helps flex toes
1st Lumbrical
Medial Plantar Nerve
flexes proximal phalanx and
"2,3,4 Lumbricals"
Lateral Plantar Nerve
extends two distal phalanges
(3rd layer)
Flexor Hallucis Brevis
Medial Plantar Nerve
flexes big toe
Flexor Digiti Minimi
Lateral Plantar Nerve
flexes little toe
Adductor Hallucis
Lateral Plantar Nerve
adducts big toe
(4th layer)
Interossei
Lateral Plantar Nerve
dorsal (4) abduct; plantar (3) adduct
Shoulder and Back
Deltoid
Axillary Nerve
"abducts, flexes, and extends arm"
Teres Major
"Lower Subscapular Nerve (C5,C6)"
adducts and medially rotates arm
Rotator Cuff:
Supraspinatus
Suprascapular Nerve
initiates abduction
Infraspinatus
Suprascapular Nerve
laterally rotates arm
Teres Minor
Axillary Nerve
laterally rotates arm
Subscapularis
Upper and Lower Subscapular Nerves
medially rotates arm
Trapezius
Spinal Accessory Nerve (CN XI)
"elevates, retracts, and depresses scapula"
Rhomboids
Dorsal Scapular
retracts scapula
Levator Scapulae
Dorsal Scapular
elevates scapula
Latissimus Dorsi
Thoracodorsal
"extends, adducts, and medially rotates arm"
Serratus Anterior
Long Thoracic
protracts scapula and holds it to thoracic wall
Flexors of Arm
Biceps Brachii
Musculocutaneous
flexes and supinates forearm
Brachialis
Musculocutaneous
flexes forearm
Coracobrachialis
Musculocutaneous
flexes and adducts arm
Muscle
Innervation
Action
Extensors of Arm
Triceps Brachii
Radial Nerve
extends forearm
Flexors of Forearm
(Superficial)
Flexor Carpi Ulnaris
Ulnar Nerve
flexes and adducts hand
Palmaris Longus
Median Nerve
flexes hand and tenses plantar aponeurosis
Flexor Carpi Radialis
Median Nerve
flexes and abducts hand
Pronator Teres
Median Nerve
pronates and flexes forearm
Flexor Digitorum Superficialis
Median Nerve
flexes fingers and wrist
(Deep)
Flexor Digitorum Profundus
Median and Ulnar
flexes fingers and wrist
Flexor Pollicis Longus
Median Nerve
flexes thumb
Pronator Quadratus
Median Nerve
pronates forearm
Extensors of Forearm
(Superficial Layer)
Brachioradialis
deep radial nerve
flexes forearm (handshake muscle)
Extensor Carpi Radialis Longus
deep radial nerve
extends and abducts hand
Extensor Carpi Radialis Brevis
deep radial nerve
extends and abducts hand
Extensor Digitorum
posterior interosseus
extends fingers
Extensor Digiti Minimi
posterior interosseus
extends little finger
Extensor Carpi Ulnaris
posterior interosseus
extends and adducts hand
(Deep Layer)
Supinator
posterior interosseus
supinates forearm
Extensor Pollicis Longus
posterior interosseus
extends thumb
Extensor Pollicis Brevis
posterior interosseus
extends thumb at metacarpophalangeal joint
Abductor Pollicis Longus
posterior interosseus
abducts thumb
Extensor Indicis
posterior interosseus
extends index finger
Muscle
Innervation
Action
Hand
(Thenar Compartment)
Abductor Pollicis Brevis
Recurrent Branch of Median Nerve
abducts thumb
Opponens Pollicis
Recurrent Branch of Median Nerve
Flexor Pollicis Brevis
Recurrent Branch of Median Nerve
Adductor Pollicis
Ulnar
(Hypothenar Compartment)
Abductor Digiti Minimi
Ulnar Nerve
abducts little finger
Opponens Digiti Minimi
Ulnar Nerve
brings little finger together with thumb
Flexor Digiti Minimi
Ulnar Nerve
flexes little finger
(Central Compartment)
1st and 2nd Lumbricals
Median Nerve
flexes proximal phalanx
3rd and 4th Lumbricals
Ulnar Nerve
and extends two distal phalanges
Interossei (7)
Deep Branch of Ulnar Nerve
dorsal (4) abduct and palmar (3) adduct
Muscles of Expresssion
Orbicularis Oris
buccal branch of facial (CN VII)
closes eyelid
Levator Labii Superiorus
buccal branch of facial (CN VII)
raises upper lip
Levator Anguli Oris
buccal branch of facial (CN VII)
raises angle of mouth
Zygomaticus Major
buccal branch of facial (CN VII)
pulls angle of mouth up and back (smiling)
Mentalis
mandibular branch of facial (CN VII)
wrinkles chin (expression of doubt)
Buccinator
buccal branch of facial (CN VII)
compresses cheeks during chewing
Nasalis
buccal branch of facial (CN VII)
compresses and opens nasal aperture
Orbicularis Oculi
temporal and zygomatic branches
closes eyelid
Platysma
cervical branch of facial (CN VII)
depresses mouth and wrinkles neck
Sternocleidomastoid
accessory nerve (CN XII)
flexes head laterally or forward
Muscle
Innervation
Action
Muscles of Mastication
Masseter
masseteric branch of manbibular
Temporalis
deep temporal branch of mandibular
Medial Pterygoid
medial pterygoid branch of mandibular
Lateral Pterygoid
lateral pterygoid branch of mandibular
Infrahyoid Muscles
Sternohyoid
ansa cervicalis (C1-C3)
depresses hyoid bone
Sternothyroid
ansa cervicalis (C1-C3)
depresses hyoid bone
Thyrohyoid
C1
depresses hyoid bone
Omohyoid
ansa cervicalis (C1-C3)
depresses hyoid bone
Suprahyoid Muscles
Digastric (ant. and post.)
"ant.: (CN V), post.: (CN VII)"
depresses mandible; elevates hyoid
Stylohyoid
stylohyoid branch of facial
elevates hyoid bone
Mylohyoid
mylohyoid branch of mandibular
elevates hyoid bone and mouth floor
Geniohyoid
C1
elevates hyoid bone
Muscles of Eye
Superior Oblique
trochlear (CN IV)
abducts and depresses eye
Inferior Oblique
oculomotor (CN III)
abducts and elevates eye
Superior Rectus
oculomotor (CN III)
adducts and elevates eye
Inferior Rectus
oculomotor (CN III)
adducts and depresses eye
Medial Rectus
oculomotor (CN III)
adducts eye
Lateral Rectus
abducens (CN VI)
abducts eye
Levator Palpebrae Superiorus
oculomotor (CN III)
raises eyelid
Muscle
Innervation
Action
Muscles of Tongue
Genioglossus
hypoglossal (CN XII)
pulls tongue forward
Hyoglossus
hypoglossal (CN XII)
depresses tongue
Styloglossus
hypoglossal (CN XII)
draws tongue up and back
Palatoglossus
pharyngeal branch of vagus (CN X)
elevates back of tongue
Muscles of Palate
Tensor Veli Palatini
branch of mandibular
tenses soft palate
Levator Veli Palatini
pharyngeal branch of vagus
elevates soft palate
Muscle of Uvula
pharyngeal branch of vagus
pulls uvula up
Palatopharyngeus
pharyngeal branch of vagus
elevates pharynx during swallowing
Muscles of Pharynx
Superior Constrictor
pharyngeal branch of vagus
peristalsis during swallowing
Middle Constrictor
pharyngeal branch of vagus
peristalsis during swallowing
Inferior Constrictor
pharyngeal branch of vagus
peristalsis during swallowing
Stylopharyngeus
Glossopharyngeal nerve (CN IX)
elevates lateral wall for swallowing and speech
Salpingopharyngeus
pharyngeal branch of vagus
raises upper lateral wall of pharynx
Muscles of Larynx
Cricothyroid
external laryngeal
stretches and tenses vocal fold
Posterior Cricoarytenoid
recurrent laryngeal
abducts vocal fold
Lateral Cricoarytenoid
recurrent laryngeal
adducts vocal fold
Thyroarytenoid
recurrent laryngeal
relaxes vocal fold
Transverse Arytenoids
recurrent laryngeal
closes aditus
Oblique Arytenoids
recurrent laryngeal
closes aditus

Data originally compiled by Aaron Berger, UCLA School of Medicine. Web conversion by Jeffrey Huo, University of Michigan Medical School. Special thanks to Peter Denk, University of Michigan Medical School. Last updated December 12th, 1997