Posterior muscles O, I, & A

Trapezius origin

• superior nuchal lines of occipital bone

• thoracic spinous process

trapezius insertion

• clavical

• acromoin of scapula

• scapular spine

trapezius action

scapula

• elevation

• depression

• retraction

Rhomboid major origin

spinous processes of T2-5

Rhomboid major insertion

medial border of scapula

Rhomboid major action

Sacpula

• retraction

• elevation

Latissimus Dorsi origin

• spinous process T7-L5

• sacrum

• ribs 8-12

• thoracolumbar fascia

latissimus dorsi insertion

intubercular groove of humerous

latissimus dorsi action

shoulder

• extension

• adduction

• internal rotation

Supraspinatus origin

supraspinous fossa of scapula

Supraspinatus insertion

greater tubercle of humerous

Supraspinatus action

• abducts arm

• stabilizes shoulder

Infraspinatus origin

infraspinous fossa of scapula

Infraspinatus insertion

greater tubercle of humerous

Infraspinatus action

• external rotation of arm

• shoulder stabalization

Teres minor origin

lateral border of scapula

Teres minor insertion

greater tubercle of humerous

teres minor action

• external rotation of the arm

• shoulder stabilization

subscapularis origin

subscapular fossa of scapula

subscapularis insertion

lesser tubercle of humerus

subscapularis action

• internal rotation of arm

• shoulder stabilization

Triceps brachii long head origin

infraglenoid tubercle of scapula

Triceps brachii lateral head origin

posterior humeral surface

Triceps brachii medial head origin

posterior humeral surface

Triceps brachii insertion

olecranon of ulna

triceps brachii action

all three heads

• elbow extension

Long head

• shoulder extension/adduction

Extensor carpi ulnaris origin

lateral epicondyle of humerous

Extensor carpi ulnaris insertion

5th metacarpal

Extensor carpi ulnaris action

wrist

• extension

• adduction

Extensor carpi radialis longus origin

lateral epicondyle of humerous

Extensor carpi radialis longus insertion

2nd metatcarpal

Extensor carpi radialis longus action

wrist

• extension

• abduction

extensor carpi radialis brevis origin

lateral epicondyle of humerous

extensor carpi radialis brevis insertion

3rd metacarpal

extensor carpi radialis brevis actions

wrist

• extension

• abduction

Gluteus maximus origin

• iliac crest

• lateral surface of illium

• sacrum

• coccyx

Gluteus maximus insertion

• it tract

• gluteal tuberosity of femur

Gluteus maximus action

hip

• extension

• external rotation

Gluteus medius origin

iliac crest

Gluteus medius insertion

greater trochanter of femur

Gluteus medius action

abducts hip

Piriformis origin

S2-4

Piriformis insertion

greater trochanter of femur

piriformis action

external rotation of hip

semimembranosus origin

ischial tuberosity

semimembranosus insertion

medial condyle of tibia

semimembranosus action

knee

• flexion

Hip

• extension

semitendinosus origin

ischial tuberosity

semitendinosus insertion

medial surface of tibia

semitendinosus action

Knee

• flexion

Hip

• extension

Bicep femoris origin

long head

• ischial tuberosity

short head

• Linea aspera of femur

Bicep femoris insertion

head of fibula

Bicep femoris action

knee

• flexion

Hip

• extension

gastrocnemius origin

femoral condyles

gastrocnemius insertion

calcaneous

gastrocnemius action

knee

• flexion

ankle

• plantar flexion

soleus origin

• head of fibula

• posterior tibia shaft

soleus insertion

calcaneus

soleus action

planter flexes ankle