Shoulder & Arm Muscles

Front 1

Trapezius

Origin: occipital bone, ligamentum nuchae & spinous processes of thoracic vertebrae

Insertion: clavicle and scapula (acromion and scapular spine)

Action: elevate, retract, depress, or rotate scapula upward and/or elevate clavicle; extend neck

Back 1

Front 2

Rhomboideus Minor

Origin: spinous process of vertebrae C7-T1

Insertion: vertebral border of scapula

Action: adducts & performs downward rotation of scapula

Back 2

Front 3

Rhomboideus Major

Origin: spinous process of superior thoracic vertebrae

Insertion: vertebral border of scapula from spine to inferior angle

Action: adducts and downward rotation of scapula

Back 3

Front 4

Levator Scapulae

Origin: transverse precesses of C1-C4 vertebrae

Insertion: vertebral border of scapula near superior angle

Action: elevates scapula

Back 4

Front 5

Serratus Anterior

Origin: anterior and superior margins of ribs 1-8 or 1-9
Insertion: anterior surface of vertebral border of scapula

Action: protracts shoulder: rotates scapula so glenoid cavity moves upward rotation

Back 5

Front 6

Pectoralis Minor

Origin: anterior surfaces and superior margins of ribs 3-5

Insertion: coracoid process of scapula

Action: depresses & protracts shoulder, rotates scapula (glenoid cavity rotates downward), elevates ribs

Back 6

Front 7

Supraspinatus

Origin: supraspinous fossa of scapula

Insertion: greater tuberacle of humerus

Action: abduction at the shoulder

Back 7

Front 8

Infraspinatus

Origin: infraspinous fossa of scapula

Insertion: greater tubercle of humerus

Action: lateral rotation at shoulder

Back 8

Front 9

Deltoid

Origin: clavicle and scapula (acromion and adjacent scapular spine)

Insertion: deltoid tuberosity of humerus

Action: abducts shoulder, flexion and extension, medial and lateral rotation of humerus

Back 9

Front 10

Teres Minor

Origin: lateral border of scapula

Insertion: greater tubercle of humerus

Action: lateral rotation at shoulder

Back 10

Front 11

Origin: inferior angle of scapula

Teres Major

Insertion: medial lip of intertubercular groove of humerus

Action: extension, adduction & medial rotation at shoulder

Back 11

Front 12

Subscapularis

Origin: subscapular fossa of scapula

Insertion: lesser tubercle of humerus

Action: medial rotation at shoulder

Back 12

Front 13

Pectoralis Major

Origin: cartilages of ribs 2-6, gladiolus & inferior, medial portion of clavicle

Insertion: crest of greater tubercle & lateral lip of intertubercular groove of humerus

Action: flexion, adduction & medial rotation at shoulder

Back 13

Front 14

Latissimus Dorsi

Origin: spinous process of inferior T and all L vertebrae, ribs 8-12, and lumbodorsal fascia

Insertion: floor of intertubercular groove of the humerus

Action: extension, adduction, and medial rotation at shoulder

Back 14

Front 15

Coracobrachialis

Origin: coracoid process

Insertion: medial margin of shaft of humerus

Action: adduction and flexion at shoulder

Back 15

Front 16

Triceps Brachii (lateral head, long head, medial head)

Origin: (Lateral) Superior, lateral margin of humerus:(Long) Infraglenoid tubercle of scapula;(Medial) Posterior surface of humerus, inferior to radial groove

nsertion: Olecranon of ulna

Action: (Lateral) extension at elbow;(Long) extension at elbow, extension & aduction at shoulder;(Medial) extension at elbow

Back 16

Front 17

Brachialis

Origin: anterior, distal surface of humerus

Insertion: ulnar tuberosity

Action: flexion at elbow

Back 17

Front 18

Brachioradialis

Origin: ridge superior to lateral epicondyle of humerus

Insertion: lateral aspect of styloid process of radius

Action: flexion at elbow

Back 18

Front 19

Pronator Teres

Origin: medial epicondyle of humerus & coronoid process of ulna

Insertion: middle of lateral surface of radius

Action: pronates forearm and hand by medial rotation of radius at radioulnar joints & flexion at elbow

Back 19

Front 20

Flexor Carpi Radialis

Origin: medial epicondyle of humerus

Insertion: bases of 2nd and 3rd metacarpal bones

Action: flexion and abduction at wrist

Back 20

Front 21

Flexor Carpi Ulnaris

Origin: medial epicondyle of humerus; adjacent medial surface of olecranon and anteromedial surface of ulna

Insertion: pisiform bone, hamate bone, and base of 5th metacarpal bone

Action: flexion and adduction at wrist

Back 21

Front 22

Extensor Carpi Ulnaris

Origin: lateral epicondyle of humerus; adjacent dorsal surface of ulna

Insertion: base of 5th metacarpal bone

Action: extension and adduction at wrist

Back 22

Front 23

Extensor Carpi Radialis Brevis

Origin: lateral epicondyle of humerus

Insertion: base of 3rd metacarpal bone

Action: extension and abduction at wrist

Back 23

Front 24

Extensor Carpi Radialis Longus

Origin: lateral supracondylar ridge of humerus

Insertion: base of 2nd metacarpal bone

Action: extension an abduction at wrist

Back 24

Front 25

Supinator

Origin: lateral epicondyle of humerus and ridge near radial notch of ulna

Insertion: anterolateral surface of radius distal to the radial tuberosity

Action: supinates forearm and hand by lateral rotation of radius at radioulnar joints

Back 25

Front 26

Biceps Brachii

Origin: (short head) from coracoid process;(long head) from supraglenoid tubercle (scapula)

Insertion: radial tuberosity

Action: flexion at elbow and shoulder; supination

Back 26

Front 27

Palmaris Longus

Origin: medial epicondyle of humerus

Insertion: palmar aponeurosis and flexor retinaculum

Action: flexion at wrist

Back 27

Front 28

Extensor Digitorum

Origin: lateral epicondyle of humerus

Insertion: posterior surfaces of phalanges, digits 2-5

Action: extension at finger joints and wrist

Back 28