Anatomy Posterior Muscles

Front 1

Upper Trapezius

Back 1

Action- Elevation, up rotation
Origin-base of skull, occipital protuberance
Insertion-posterior aspect of the lateral third of the clavicle

Front 2

Middle Trapezius

Back 2

Action- Elevation, Adduction, up rotation
Origin-Spinous process of 7th cervical and upper 3 thoracic vertebrae
Insertion-Medial bordero fthe acromion process and superior border of the scapular spine

Front 3

Lower Trapezius

Back 3

Action- Adduction, Depression, Up rotation
Origin- spinous process of 4-12 thoracic vertebrae
Insertion- Triangular space at the base of the scapular spine

Front 4

Rhomboids

Back 4

Action- Adduction, Down rotation, elevation
Origin-spinous process of the last cervical and the first 5 thoracic
Insertion- Medial border of the scapula below the spine

Front 5

Serratus Anterior

Back 5

Action- Abducts scapula
Origin- upper 8 or 9 ribs
Insertion- medial border of the scapula

Front 6

Levator Scapulae

Back 6

Action- elevation
Origin- Transverse processes of the upper 4 cervical vertebrae
Insertion- Medial border of the scapula

Front 7

Teres Major

Back 7

Action- extension, Adduction, Internal rotation
Origin- Posteriorly on the inferior 1/3 of the lateral border of the scapula just superior to the inferior angle
Insertion- Medial lip of the bicipital groove of the humerus

Front 8

Teres Minor

Back 8

Action-external rotation, horizontal abduction, diagonal adduction
Origin- Posteriorly on upper and middle aspect of the lateral border of scapula
Insertion-posteriorly on greater tubercle of humerus

Front 9

Infraspinatus

Back 9

Action- External rotation, Horizontal abduction, diagonal abduction
Origin- Medial aspect of the infraspinatus fossa just below the spine of the scapula
Insertion- Posteriorly on the greater tubercle of the humerus

Front 10

Posterior Deltoid

Back 10

Action- Abduction, Horizontal abduction, diagonal abduction
Origin- inferior edge of the spine of the scapula
Insertion- deltoid tuberosity

Front 11

Supraspinatus

Back 11

Action-abduction
Origin- medial 2/3 of supraspinatus fossa
Insertion- superior portion of greater tubercle

Front 12

Latissimus Dorsi

Back 12

Action- extension, adduction, internal rotation
Origin- posterior crest of ilium back of sacrum and spinous processes of the lumbar and lower 6 thoracic vertebrae
Insertion- Medial side of the bicipital groove of humerus

Front 13

Treceps Brachii Long Head

Back 13

Action- Extension of elbow, extension of shoulder, adduction of shoulder
Origin- Infragleniod tubercle below the inferior lip of glenoid fossa
Insertion- olecranon process

Front 14

Triceps Brachii Lateral Head

Back 14

Action- extension of elbow
Origin- upper 1/2 of posterior surface of humerus
Insertion- Olecranon Process

Front 15

Triceps Brachii Medial Head

Back 15

Action- Extension of elbow
Origin- Distal 2/3 of the posterior surface of the humerus
Insertion-Olecranon process

Front 16

Brachioradialis

Back 16

Action- Flexion of elbow, pronation, supination
Origin- Distal 2/3 of the lateral condyoid ridge of the humerus
Insertion-Lateral surface of hte distal end of the styloid process of the radius

Front 17

Extensor Carpi Ulnaris

Back 17

Action- extension of the wrist, Adduction of the wrist, weak extension of the elbow
Origin- Lateral epicondyle of the humerus and middle 1/2 of the posterior border of the ulna
Insertion- Base of the 5th metacarpal on the dorsal surface

Front 18

Extensor Carpi Radialis Brevis

Back 18

Action- Extension of the wrist, Abduction of the wrist
Origin- Lateral epicondyle of the humerus
Insertion-Base of the 3rd metacarpal on dorsal side

Front 19

Extensor Carpi Radialis Longus

Back 19

Action- Extension of the wrist, Abduction of the wrist, Weak extension of the elbow
Origin-Lower 1/3 of the lateral supracondylar ridge of the humerus and lateral epicondyle of the humerus
Insertion-Base of the 2nd metacarpal on dorsal surface

Front 20

Extensor Digitorum

Back 20

Action- Extension of the 2nd, 3rd, 4th, and 5th phalanges at the metacarpophalangeal junction, extension of the wrist, weak extension of the elbow
Origin-lateral epicondyle of the humerous
Insertion- four tendons to bases of 2nd and 3rd phalanges on 4 fingers on dorsal surface

Front 21

Abductor Pollicis Longus

Back 21

Action- Abduction of the thumb, abduction of the wrist
Origin- Posterior aspect of radius and midshaft of ulna
Base of the 1st metacarpal on dorsal surface

Front 22

Extensor Pollicis Longus

Back 22

Action- Extension of the thumb, extension of the wrist
Origin-Posterior lateral surface of the lower middle ulna
Insertion- base of distal phalanx of the thumb on dorsal surface

Front 23

Extensor Pollicis Brevis

Back 23

Action-Extension of the thumb at the metacarpophalangeal junction, weak wrist extension
Origin-Posterior surface of the lower middle radius
Insertion-Base of proximal phalanx of thumb on dorsal surface

Front 24

Supinator

Back 24

Action- Supination of forearm
Origin-Lateral epicondyle of the humerus and neighboring posterior part of the ulna
Insertion-Lateral surface of the proximal radius just below the head

Front 25

Biceps Femoris

Back 25

Action-extension of the hip, flexion of the knee, external rotation of the hip, external knee rotation
Origin-Long head: ischial tuberosity, short head;lower half of the linea aspera and lateral condyloid ridge
Insertion-Head of the fibula and lateral condyle of the tibia

Front 26

Semitendinosus

Back 26

Action- Extension of the hip, flexion of the knee, internal rotation of the hip, internal knee rotation
Origin- Ischial Tuberosity
Insertion- upper anterior medial surface of the tibia just below the condyle

Front 27

Semimembranosus

Back 27

Action- extension of the hip, flexion of the knee, internal rotation of the hip, internal knee rotation
Origin- Ischial tuberosity
Insertion- Posteromedial surface of the medial tibial condyle

Front 28

Gluteus Maximus

Back 28

Action- Extension of the hip, external rotation of the hip, lower fibers assist in adduction
Origin- posterior 1/4 of the crest of the ilium, posterior surface of the sacrum and coccyx and pascia of the lumbar area
Insertion- obliqeu ridge on the lateral surgace of the greater trochanter and the iliotibial band of the fasciae latae

Front 29

Gluteus Medius

Back 29

Action- abduction of the hip, external rotation as the hip abducts, Internal rotation (anterior fibers)
Origin- Lateral surface of the ilium just below the crest
Insertion-Posterior and middle surfaces of the greater trochanter

Front 30

Gluteus Minimus

Back 30

Action- Abduction of the hip, Hip internal rotation as femus is abducted
Origin- Later surface of the ilium just below the origin of the gluteus medius
Insertion- Anterior surface of the greater trochanter

Front 31

Tensor fasciae latae

Back 31

Action- abduction of the hip, flexion of the hip, internal rotation of the hip as it flexes
Origin- Anterior iliac crest and surface of the ilium just below the crest
Insertion- 1/4 of the way down the thigh into the iliotibial tract

Front 32

Gastrocnemius

Back 32

Action- Plantar flexion o fthe ankle, flexion of the knee
Origin- Medial head: posterior surface of the medial femoral condyle, lateral head: posterior surface of the lateral femoral condyle
Insertion- posterior surface of the calcaneus

Front 33

Soleus

Back 33

Action- plantar flexion of the ankle
Origin- Posterior surface of the proximal fubula and proximal 2/3 of the posterior tibial surface
Insertion-Posterior surface of the calcaneus

Front 34

Tibialis Posterior

Back 34

Action- inversion of the foot, plantar flexion of the ankle
Origin- Posterior surface of the upper 1/2 of the interosseus membrane and the adjacent surgaces of the tibia and fibula
Insertion- lower inner surfaces of the navicular and cuneiform bones and bases of the 2-5 metatarsal bones

Front 35

Flexor Digitorum Longus

Back 35

Action- Flexion of the 4 lesser toes, plantar flexion of the ankle, inversion of the foot
Origin- middle 1/3 of the posterior surface of the tibia
Insertion- Base of the distal phalanx of each of the four lesser toes

Front 36

Flexor Hallicus Longus

Back 36

Action- Flexion of the great toe, Inversion of the foot, plantar flexion of the ankle
Origin- Middle 2/3 of the posterior surface of the fibula
Insertion- Base of the distal phalanx of the big toe, under surface

Front 37

Peroneus Longus

Back 37

Action- Eversion of the foot, Plantar flexion of the ankle
Origin- head and upper 2/3 of the lateral surface of the fibula
Insertion- Under surfaces of the medial cuneiform and 1st metatarsal

Front 38

Peroneus Brevis

Back 38

Action- Eversion of the foot, plantar flexion of the ankle
Origin- Lower 2/3 of the lateral surface of the fibula
Insertion- Base of the 5th metatarsal

Front 39

Erector Spinae

Back 39

Action- Lateral flexion of the spine, extension of the spine
Origin- Thoracolumbar aponeurosis from sacrum to posterior ribs and transverse processes of thoracic vertebrae
Insertion-Cervical, thoracic transverse processes

Front 40

Quadratus Lumborum

Back 40

Action- Lateral flexion to the side on which it is located, stabilizes the pelvis and lumbar spine
Origin- Posterior inner lip of the iliac crest
Insertion- Approx. 1/2 length of the lower border of the 12th rib and the transverse process of the 4 upper lumbar vertebrae