Muscles Of The Upper Extremities - Action

Front 1

Upper Trapezius

Back 1

Elevation and Lateral (upward) rotation of scapula

Front 2

Middle Trapezius

Back 2

Adduction (retraction) of scapula

Front 3

Lower Trapezius

Back 3

Depression and Lateral (upward) rotation of scapula

Front 4

Levator Scapula

Back 4

Elevation and Medial (downward) rotation of scapula

Front 5

Rhomboid Major and Minor

Back 5

Adduction (retraction) and Medial (downward) rotation of scapula

Front 6

Serratus Anterior

Back 6

Abduction (protraction), Depression (lower fibers), and Lateral (upward) rotation of scapula; Stabilizes scapula against chest wall; Assists forced exhalation

Front 7

Pectoralis Major

Back 7

Adduction, Horizontal adduction, and Medial rotation of Humerus;

Clavicular Head: Flexion of Humerus

Sternocostal Head: Extension of Humerus, Assists anterior tilt of scapula

Front 8

Pectoralis Minor

Back 8

Abduction (protraction), Depression, Medial (downward) rotation, and Anterior tilt of Scapula; Assists forced inhalation

Front 9

Subclavius

Back 9

Depresses clavicle and stabilizes sternoclavicular joint

Front 10

Latissimus Dorsi

Back 10

Extension, Medial rotation, and Adduction of Humerus; Medial (downward) rotation of scapula; Assists depression of scapula

Front 11

Supraspinatus

Back 11

Abduction and Scaption of Humerus; Stabilization of Head of Humerus

Front 12

Infraspinatus

Back 12

Lateral rotation and Extension of Humerus

Front 13

Teres Minor

Back 13

Lateral rotation and Extension of Humerus

Front 14

Teres Major

Back 14

Extension, Medial rotation, and Adduction of Humerus

Front 15

Subscapularis

Back 15

Medial rotation and Adduction of Humerus

Front 16

Anterior Deltoid

Back 16

Flexion, Horizontal adduction, and Medial rotation of Humerus

Front 17

Middle Deltoid

Back 17

Abduction of Humerus to 90 degrees

Front 18

Posterior Deltoid

Back 18

Extension, Horizontal abduction, Lateral rotation, and Scaption of Humerus

Front 19

Coracobrachialis

Back 19

Flexion and Adduction of Humerus

Front 20

Biceps Brachii

Back 20

Flexion of elbow and Supination of forearm

Short Head only: Flexion of Humerus

Front 21

Brachialis

Back 21

Flexion of Elbow

Front 22

Triceps Brachii

Back 22

Long Head: Extension of Humerus

Lateral Head: Extension of Elbow

Medial Head: Extension of Elbow

Front 23

Anconeus

Back 23

Assists extension of Elbow

Front 24

Flexor Carpi Radialis

Back 24

Flexion and Abduction (radial deviation) of wrist

Front 25

Flexor Carpi Ulnaris

Back 25

Flexion and Adduction (ulnar deviation) of wrist

Front 26

Palmaris Longus

Back 26

Assists flexion of wrist

Front 27

Pronator Teres

Back 27

Pronation of forearm and Assists in flexion of elbow

Front 28

Pronator Quadratus

Back 28

Pronates forearm

Front 29

Flexor Digitorum Superficialis

Back 29

Flexion of fingers 2 - 5 at PIP joints and Assists flexion of wrist

Front 30

Flexor Digitorum Profundus

Back 30

Flexion of fingers 2 - 5 at DIP joints, Assists flexion of wrist

Front 31

Flexor Policis Longus

Back 31

Flexion of thumb at IP joint

Front 32

Brachioradialis

Back 32

Flexion of elbow with forearm in mid-position (halfway between supination and pronation)

Front 33

Extensor Carpi Radialis Longus

Back 33

Extension and Abduction (radial deviation) of wrist

Front 34

Extensor Carpi Radialis Brevis

Back 34

Extension of wrist

Front 35

Extensor Carpi Ulnaris

Back 35

Extension and Adduction (ulnar deviation) of wrist

Front 36

Extensor Digitorum

Back 36

Extension of fingers 2 - 5 at MP joints and Assists extension of wrist

Front 37

Extensor Digiti Minimi

Back 37

Extension of 5th finger at MP joint and Assists extension of wrist

Front 38

Supinator

Back 38

Supination of forearm

Front 39

Extensor Indicis

Back 39

Extension of index finger at MP joint and Assists extension of wrist

Front 40

Abductor Pollicis Longus

Back 40

Abduction of thumb at CM joint and Assists wrist abduction

Front 41

Extensor Pollicis Longus

Back 41

Extension of thumb at IP joint

Front 42

Extensor Pollicis Brevis

Back 42

Extension of thumb at MP joint and Assists wrist abduction

Front 43

Abductor Pollicis Brevis

Back 43

Abduction of thumb at CM joint

Front 44

Flexor Pollicis Brevis

Back 44

Flexion of thumb at MP joint

Front 45

Opponens Pollicis

Back 45

Opposition of thumb at CM joint (thumb opposition is the combined movement of abduction, flexion, and medial rotation of the CM joint of the thumb that occurs simultaneously as the opponens pollicis contracts)

Front 46

Adductor Pollicis

Back 46

Adduction of thumb at CM joint

Front 47

Flexor Digiti Minimi Brevis

Back 47

Flexion of 5th finger at MP joint

Front 48

Opponens Digiti Minimi

Back 48

Opposition of 5th finger at CM joint

Front 49

Abductor Digiti Minimi

Back 49

Abduction of 5th finger at MP joint

Front 50

Lumbricals

Back 50

Flexion of fingers at MP joints and Extension of fingers at PIP and DIP joints

Front 51

Palmar Interossei

Back 51

Adduction of fingers 2 - 5 at MP joints and Assists Lumbricals in MP flexion and PIP and DIP extension of fingers 2 - 5

Front 52

Dorsal Interossei

Back 52

Abduction of 2nd and 4th fingers at MP joint, Abduction and Adduction of 3rd finger at MP joint, Assists lumbricals in MP flexion and PIP and DIP extension of fingers 2 - 4