Muscle Identification

Soleus

O: proximal tibia and fibula

I: calcaneus through calcaneal (Achille’s) tendon

A: plantar flexes foot

Semimembranosus

O: Ischial tuberosity

I: Medial tibial condyle

A: Extends thigh, flexes and medially rotates leg

Extensor digitorum longus

O: Lateral tibial condyle, fibula shaft

I: Middle and distal phalanges

A: Extends toes (except for big toe), dorsiflexes and everts foot

Gastrocnemius

O: Lateral and medial condyles of femur

I: Calcaneus

A: Flexes leg, plantar flexes foot

Vastus medialis

O: Linea aspera of femur

I: Tibial tuberosity

A: Extends leg

Vastus lateralis

O: Greater trochanter and linea aspera of femur

I: Tibial tuberosity

A: Extends leg

Rectus femoris

O: Anterior inferior iliac spine

I: Tibial tuberosity

A: Flexes thigh, extends leg

Vastus intermedius

O: Anterior and lateral part of femur

I: Tibial tuberosity

A: Extends leg

Quad muscle

• Main action: extension of leg

• Insertion: tibial tuberosity

• Nerve: femoral nerve

Gluteus maximus

O: Lateral surface of ilium, sacrum, coccyx
I: Lateral condyle of tibia, tuberosity of femur
A: Extends, abducts, laterally rotates thigh
N: Gluteal nerve

Gletus medius

O: Outer ilium

I: Greater trochanter of femur

A: Medially rotates and abducts thigh

Biceps femoris

O: Ischial tuberosity

I: Head of fibula, lateral tibia

A: Extends thigh, flexes and laterally rotates leg

Tibialis anterior

O: Lateral tibia

I: First metatarsal

A: Dorsiflexes and inverts foot

Sartorius

O: Anterior superior iliac spine

I: Medial side of tibial tuberosity

A: Flexes and laterally rotates thigh, flexes leg

Gracilis

O: Pubis

I: Proximal tibia

A: Adducts thigh, flexes leg

Psoas major

O: Thoracic vertebrae 12, Lumbar 1-5

I: Lesser trochanter of femur

A: Flexes thigh and lumbar vertebrae

Flexor carpi radialis

O: Medial epicondyle of humerus

I: Metacarpals 2 and 3

A: Flexes and abducts hand

Flexor pollicis longus

O: Anterior radius and interosseus membrane

I: Distal thumb phalanges

A: Flexes thumb

Brachialis

O: Anterior, distal humerus

I: Coronoid process of ulna

A: Flexes forearm

Biceps brachii

O: Supraglenoid tubercle and coracoid process of scapula

I: Radial tuberosity

A: Flexes arm, laterally rotates and flexes forearm

Brachioradialis

O: Supracondylar ridge of humerus

I: Styloid process of radius

A: Flexes forearm

External oblique

O: Ribs 5-12

I: Iliac crest, inguinal ligament

A: Compresses abdomen, laterally rotates trunk

Interal oblique

O: Inguinal ligament, iliac crest

I: Linea alba, inferior 4 ribs

A: Compresses abdomen, laterally rotates trunk

Rectus abdominus

O: Symphysis pubic, pubic crest

I: Cartilages of ribs, xiphoid process (sternum)

A: Flexes lumbar vertebrae, compresses abdomen

Transversus abdominus

O: Iliac crest, ribs 7-12

I: Linea alba, pubis

A: Compresses abdomen, laterally rotates trunk

Triceps brachii

O: Posterior surface of humerus, infraglenoid tuberosity of scapula

I: Olecranon process

A: Adducts arm, extends arm and forearm

Intercostal muscles

O: Inferior margin of ribs 1-11

I: Superior margin of ribs 2-12

A: Elevates/depresses ribs

Pectoralis major

O: Ribs, sternum, clavicle

I: Intertubercular groove of humerus

A: Adduction of the arm, rotates arm medially

Deltoid

O: Clavicle, acromion, spine of scapula

I: Deltoid tuberosity

A: Abducts, flexes, extends medially, and laterally rotates arm

Trapezius

O: Occipital protuberance, cervical vertebrae 7 to thoracic 12

I: Clavicle, acromion, spine of scapula

A: Abducts and extends head, rotates and adducts scapula

Latissimus dorsi

O: thoracic and lumbar vertebrae, sacrum, iliac crest, ribs

I: Intertubercular groove of humerus

A: Adducts, extends, medially rotates arm, pulls shoulder inferiorly

Sternocleidomastoid muscle

O: Sternum and clavicle

I: Mastoid process

A: Rotates and extends head (one), flexes head (both)

Platysma

O: Fascia over pectoralis major and deltoid muscle

I: Mandible and skin inferior to lower lip

A: Depresses lower lip

Orbicularis oris

O: Muscles encircling mouth

I: Skin of lips

A: Closes mouth

Zygomaticus

O: Zygomatic bone

I: Angle of mouth

A: Elevates corners of mouth (smile)

Frontalis

O: Galea aponeurotica

I: Skin near eyebrows

A: Raises eyebrows, pulls scalp anteriorly

Masseter

O: Zygomatic arch

I: Ramus of mandible

A: Closes mandible

Temporalis

O: Temporal fossa

I: Coronoid process and ramus of mandible

A: Closes mandible

Orbicularis oculi

O: Frontal bone and maxilla

I: Eyelid

A: Closes eye

Buccinator

O: Mandible and maxilla

I: Orbicularis oris

A: Tightens cheek