Muscle Practical

rectus femoris

Origin: Anterior inferior iliac spine

Insertion: Patella

Action: Flex the hip, extend the leg

temporalis

Origin: Lateral surface of temporal and parietal bones

Insertion: Coronoid process of mandible

Action: Elevates mandible

masseter

Origin: Zygomatic arch

Insertion: Ramus of mandible

Action: Elevates mandible

splenius captius

Origin: Spinus processes of cervical vertebrae

Insertion: Mastoid process, occiput, superior cervical spine

Action: Rotate neck laterally

sternocleidomastoid

Origin: Sternum, clavicle

Insertion: Mastoid process of temporal bone

Action: Rotate neck laterally

trapezius

Origin: Midline of neck and back

Insertion: Clavicles and scapular spine

Action: Elevate, retract, depress, rotate scapula; elevate clavicle; extend neck

rhomboids

Origin: Spinus process of upper thoracic vertebrae

Insertion: Medial border of scapula

Action: Adducts scapula, downward rotation

serrates anterior

Origin: First 8 ribs

Insertion: Anterior surface of medial border of scapula

Action: Protracts and upwardly rotate scapula, contract to stabilize arm

pectoralis minor

Origin: Upper ribs

Insertion: Corocoid process

Action: Depress, protract, downwardly rotate scapula

deltoid

Origin: Clavicle, acromion, lateral scapular spine

Insertion: Deltoid tuberosity of humerus

Action: Abduction at shoulder; flexion and medial rotation; extension and lateral rotation of arm

pectoralis major

Origin: Anterior portion of chest

Insertion: Crest of greater tubercle of humerus

Action: Flexion, adduction, medial rotation at shoulder

latissimus dorsi

Origin: Thoracic vertebrae at posterior midline

Insertion: Intertubercular groove of humerus

Action: Extends, adducts, and laterally rotates humerus

teres major

Origin: Lateral border of scapula

Insertion: Intertubercular groove of humerus

Action: Extension, adduction, and medial rotation at shoulder

coracobrachialis

Origin: Corocoid process

Insertion: Medial shaft of humerus

Action: Adduction and flexion at shoulder

subscapularis

Origin: Subscapular fossa of scapula

Insertion: Lesser tubercle of humerus

Action: Medially rotates shoulder

infraspinatus

Origin: Infraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: Laterally rotate humerus

teres minor

Origin: Lateral border of scapula

Insertion: Greater tubercle of humerus

Action: Laterally rotate humerus

supraspinatus

Origin: Supraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: Abducts shoulder

biceps brachii

Origin: Superior lip of glenoid fossa; corocoid process

Insertion: Radial tuberosity

Action: Flexion at elbow and shoulder

triceps brachii

Origin: Lateral superior humeral shaft; posterior superior humerus; inferior lip of glenoid fossa

Insertion: Olecranon process of ulna

Action: Extension at elbow, extension and adduction at shoulder

brachialis

Origin: Distal anterior surface of humerus

Insertion: Proximal ulna

Action: Flexion at elbow

brachioradialis

Origin: Distal humerus, superior to lateral epicondyle

Insertion: Styloid process of radius

Action: Flexion at elbow

extensor carpi radialis

Origin: Lateral epicondyle

Insertion: Posterior side of second and third metacarpals

Action: Extend and abduct the wrist

extensor digitorum

Origin: Lateral epicondyle

Insertion: Posterior phalanges

Action: Extends wrist and fingers

extensor carpi ulnaris

Origin: Lateral epicondyle

Insertion: Posterior side of fifth metacarpal

Action: Extends and adducts the wrist

supinator

Origin: Lateral epicondyle, near radial notch

Insertion: Anterior and lateral surface of radius

Action: Supinates the forearm

pronator teres

Origin: Medial epicondyle

Insertion: Middle of radius

Action: Pronates lower arm

flexor carpi radialis

Origin: Medial epicondyle

Insertion: Base of second and third metacarpals

Action: Flexion at wrist and abduction of hand and wrist

flexor carpi ulnaris

Origin: Medial epicondyle

Insertion: Anterior surface of fifth metacarpal

Action: Flexes and adducts hand

palmaris longus

Origin: Medial epicondyle

Insertion: Palmar aponeurosis

Action: Flexion at the wrist and hand joints

flexor digitorum

Origin: Medial epicondyle

Insertion: Palmar aponeurosis

Action: Flexion at the wrist and hand joints

erector spinae

Origin: Spinous processes of inferior thoracic, iliac crest

Insertion: Upper thoracic and cervical regions of body

Action: Extend and laterally flex spine

rectus abdominis

Origin: Pubic crest

Insertion: Xiphoid process and middle costal cartilages

Action: Flex spine and trunk of body

exterior obliques

Origin: Ribs 5-12

Insertion: Iliac crest and pubic tubercle

Action: Bilateral contraction for twisting of trunk

interior obliques

Origin: Inguinal ligament, iliac crest

Insertion: Ribs 10-12

Action: Flexes trunk, depresses lower ribs

transversus abdominis

Origin: Inguinal ligament, costal cartilages 7-12, iliac crest

Insertion: Xiphoid process. Linea alba, pubic crest

Action: Contracts spine

respiratory diaphragm

Origin: Lumbar vertebrae and inferior border of ribs and sternum

Insertion: On itself

Action: Contracts to allow expansion of thoracic cavity

intercostal

Origin: Costal groove

Insertion: Superior aspect of rib

Action: Depress ribs during breathing

psoas major

Origin: Transverse processes of T12-L5

Insertion: Lesser trochanter of femur

Action: Flexion and lateral rotation of the hip joint

iliacus

Origin: Iliac fossa and anterior inferior iliac spine

Insertion: Lesser trochanter of femur

Action: Flexes and rotates hip joint

iliopsoas

Origin: Lumbar vertebrae

Insertion: Lesser trochanter of femur

Action: External rotation of hip joint

gluteus maximus

Origin: Iliac crest, lateral surface of ilium

Insertion: Iliotibial tract and gluteal tuberosity of femur

Action: Extension and lateral rotation at hip

gluteus medius

Origin: Anterior iliac crest

Insertion: Greater trochanter of femur

Action: Abduction and medial rotation at hip

tensor fascia lata

Origin: Iliac crest

Insertion: Iliotibial tract

Action: Flexion and medial rotation at hip

piriformis

Origin: Anterolateral surface of sacrum

Insertion: Greater trochanter of femur

Action: Lateral rotation and abduction at hip

vastus medialis

Origin: Upper part of femoral shaft

Insertion: Upper border of patella

Action: Extends knee

vastus lateralis

Origin: Greater trochanter

Insertion: Patella

Action: Extends knee

vastus intermedius

Origin: Anterior and lateral surfaces of femur

Insertion: Base of patella

Action: Extends leg at knee

sartorius

Origin: Anterior superior iliac spine

Insertion: Medial side of proximal tibia

Action: Flexes hip, rotates thigh laterally

adductor longus

Origin: Inferior ramus of pubis

Insertion: Linea aspera

Action: Adduction, flexion, and medial rotation at hip

adductor Magnus

Origin: Inferior ramus of pubis

Insertion: Linea aspera

Action: Adduction at hip, flexion and medial rotation, extension and lateral rotation

gracilis

Origin: Inferior ramus of pubis

Insertion: Medial surface of tibia, inferior to medial condyle

Action: Flexion at knee, adduction and medial rotation at hip

biceps femoris

Origin: Ischial tuberosity

Insertion: Head of fibula, lateral condyle of tibia

Action: Flexion at knee, extension

semitendonosus

Origin: Ischial tuberosity

Insertion: Proximal, medial surface of tibia

Action: Flexion at knee, extension and medial rotation at hip

semimembranosus

Origin: Ischial tuberosity

Insertion: Posterior surface of medial condyle of tibia

Action: Flexion at knee, extension and medial rotation at hip

gastrocnemius

Origin: Femoral condyles

Insertion: calcaneus

Action: Plantar flexion at ankle, inversion of foot, flexion at knee

soleus

Origin: Head and proximal shaft of fibula

Insertion: Calcaneus (w/ gastrocnemius)

Action: Plantar flexion at knee

tibialis anterior

Origin: Lateral condyle and proximal shaft of tibia

Insertion: Base of first metatarsal bone, medial cuneiform bone

Action: Dorsiflexion at ankle, inversion of foot

fibulas longus

Origin: Lateral condyle of tibia, head of fibula

Insertion: Base of first metatarsal bone, medial cuneiform bone

Action: Eversion of foot and plantar flexion at ankle

extensor digitorum

Origin: Lateral condyle of tibia, anterior surface of fibula

Insertion: Superior surfaces of phalanges

Action: Extensions at joints of toes 2-5

tibialis posterior

Origin: Interosseous membrane and shafts of tibia/fibula

Insertion: Tarsal and metatarsal bones

Action: Adduction and inversion of foot, plantar flexion at ankle