Skeletal Muscles

Front 1

Trapezius (origin, insertion and action)

Back 1

Origin: occipital bone, ligamentum nuchae, spines of thoracic (and cervical) vertebra

Insertion: Clavical, acromion process, spine of the scapula

(ie. the trapezius runs from the upper skeleton to the spine of the scapula)

Action: Elevate scapula, upward rotation of the shoulder, adduction of the scapula

Front 2

Rhomboids (origin, insertion and action)

Back 2

Origin: C7-T5

Insertion: Medial border of the scapula

Action: Adduction of the scapula when the rhomboids contract (inferior angle rotates inward)

Front 3

Serratus anterior (origin, insertion and action)

Back 3

Origin: Lateral surface of the upper 8 ribs

Insertion: Medial border of the scapula (anterior surface)

Action: Abducts the scapula and causes upward rotation of the point of the shoulder

(used to throw muscles, throw punches)

Front 4

Levator scapula

Back 4

Origin: Transverse processes of the upper 4 C vertebrae

Insertion: Superior angle of scapula

Elevates medial border of scapula.

Front 5

Pectoralis minor

Back 5

Origin: Outer surface of ribs 3-5

Insertion: Coracoid process of scapula

Action: Abducts (or protracts) scapula with the serratus anterior. Causes downward rotation of the point of the shoulder (in contrast to the serratus anterior)

Front 6

Deltoid spinal (posterior) head

Back 6

Origin: Spine of scapula

Insertion: Deltoid tuberosity of the humerus

Action: Extension of the shoulder, lateral rotation of humerus

Front 7

Deltoid acromial (lateral) head

Back 7

Origin: Acromion

Insertion: Deltoid tuberosity of the humerus

Action: Shoulder abduction

Front 8

Clavicular (anterior) head

Back 8

Origin: Clavicle

Insertion: Deltoid tuberosity of the humerus

Action: Flexion of the shoulder, medial rotation of humerus

Front 9

Pectoralis major

Back 9

Origin: Medial part of the clavicle and costal cartilage of 1-6 ribs

Insertion: Bicipital groove of humerous

Action: Flexion of the shoulder, extension of a flexed shoulder, medial rotation of humerus, horizontal flexion

Front 10

Latissimus dorsi

Back 10

Origin: Back of the sacrum, L vertebrae, lower thoracic vertebrae

Insertion: Bicipital groove of humerus

Action: Shoulder extension, humerus medial rotation, humerus adduction (same as teres major)

Front 11

What muscles are used to shrug?

Back 11

Levator scapula and trapezius

Front 12

What muscles are used for the medial rotation of the humerus?

Back 12

Clavicular deltoid head
Pectoralis major
Latissimus dorsi
Subscapularis
Teres major

Front 13

What muscles are involved with scapula abduction?

Back 13

Trapezius (tugs on superior head and border of scapula), serratus anterior

Front 14

What muscle is involved with shoulder abduction?

Back 14

Acromial deltoid head & supraspinatus

Front 15

What muscle is involved with the extension of the shoulder and lateral rotation of the humerus?

Back 15

Spinal deltoid head

Front 16

Shoulder extension muscles

Back 16

Spinal deltoid head, latissimus dorsi, teres major, long head of triceps

Front 17

Humerus adduction muscles

Back 17

Latissimus dorsi, teres minor, subscapularis

Front 18

Lubodorsal aponeurosis

Back 18

Layers of tendons that connect latissimus dorsi to lower spine.

Front 19

[Rotator cuff muscle]
Supraspinatus muscle

Back 19

Oirgin: Supraspinatus fossa of the scapula

Insertion: Greater tubercle of the humerus

Action: Strength and stability to shoulder joint; initiates shoulder abduction (deltoid takes over subsequent abduction)

Front 20

[Rotator cuff muscle]
Infraspinatus muscle

Back 20

Oirgin: Infraspinatus fossa of the scapula

Insertion: Greater tubercle of the humerus

Action: Provides strength to posterior component of the shoulder joint capsule; lateral rotation of the humerus

Front 21

What muscles are involved with the lateral rotation of the humerus?

Back 21

Infraspinatus muscle
Spinal deltoid head
Teres minor

Front 22

[Rotator cuff muscle]
Teres minor

Back 22

Origin: Lateral border of the scapula

Insertion: Greater tubercle below infraspinatus

Action: Provides posterior support to shoulder joint, lateral rotation of humerus, adduction to humerus

Front 23

[Rotator cuff muscle]
Subscapularis

Back 23

Origin: Subscapular fossa of the scapula

Insertion: Lesser tubercle of humerus

Action: Provides anterior strength to shoulder joint.
Medial rotation of humerus.
Adducts humerus.

Front 24

Supraspinatus

Infraspinatus

Teres Minor

Subscapularis

Acromion

Coracoid process

Back 24

Front 25

Teres major

Back 25

Origin: Lateral border of the scapula

Insertion: Bicipital groove of humerus

Action: Shoulder extension, medial rotation as humerus (like lat dorsi)

Front 26

[Biceps brachii] Short head

Back 26

Origin: Coracoid process of scapula

Insertion: Radial tuberosity

Action: Shoulder flexion, elbow flexion, forearm supination

[Also part of elbow joint]

Front 27

[Biceps brachii] Long head

Back 27

Origin: Supraglenoid tubercle of scapula

Insertion: Radial tuberosity

Action: Shoulder flexion, elbow flexion, forearm supination

[Also part of elbow joint]

Front 28

[Triceps brachii] Long head

Back 28

Origin: Infraglenoid tubercle of the scapula

Insertion: Olecranon (ulna)

Action: Shoulder & elbow extension

[Also part of elbow joint]

Front 29

[Triceps brachii] Medial head

Back 29

Origin: Posterior/medial of humerus

Insertion: Olecranon (ulna)

Action: Elbow extension (not attached to shoulder)

[Also part of elbow joint]

Front 30

[Triceps brachii] Lateral head

Back 30

Origin: Posterior lateral humerus

Insertion: Olecranon (ulna)

Action: Elbow extension (not attached to shoulder)

[Also part of elbow joint]

Front 31

Coracobrachialis

Back 31

Origin: Coracoid process of scapula

Insertion: Medial side of humerus shaft

Action: Shoulder flexion

Front 32

Brachialis

Back 32

Origin: Anterior shaft of humeruss

Insertion: Coronoid process of ulna

Action: Elbow flexion

Front 33

Brachioradialis

Back 33

From humerus shaft (right above lateral epicondyle) to styloid process of radius

Action: Elbow flexion (when forearm is semi-pronated)

Front 34

Supinator

Back 34

Lateral epicondyle of humerus to anterolateral surface of radius

Action: Supination of forearm, assists in elbow extension

Front 35

Elbow flexion

Back 35

Brachialis
Biceps brachii

Pronator teres
Brachioradialis

Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus

Front 36

Elbow extension

Back 36

Triceps brachii
Supinator

Front 37

Pronator teres

Back 37

[1st layer]

Medial epicondyle of humerus to lateral surface of radius

Assists in elbow flexion
Used in forearm pronation

Front 38

Palmar aponeurosis

Back 38

Layer of tendon covering palm, serves as insertion point for Palmaris Longus

Front 39

Flexor retinaculum

Back 39

Band of CT stretching from lateral carpal bones to medial carpal bones

Front 40

Palmaris longus (which layer?)

Back 40

[1st layer]

Medial epicondyle of humerus to palmar aponeurosis

For elbow and wrist flexion

Front 41

Flexor carpi radialis (which layer?)

Back 41

[1st layer]

From the medial humerus epicondyle to the base of 2nd and 3rd metacarpals. Passes under flexor retinaculum.

Elbow & wrist flexion and abduction.

Front 42

Flexor carpi ulnaris (which layer?)

Back 42

[1st layer]

From the medial humerus epicondyle to the base of 5th metacarpal. Passes under flexor retinaculum.

Elbow & wrist flexion and adduction.

Front 43

Flexor digitorum superficialis (which layer?)

Back 43

[2nd layer]

From the medial epicondyle of the humerus, coronoid process & radial shaft

Attach to the middle phalanx of your 4 digits

Flexion of:
Elbow, wrist
Metacarpal phalangeal and 1st interphalangeal joints

Front 44

Flexor digitorum profundus (which layer?)

Back 44

[3rd layer]

From anterior surface of ulna and interosseous membrane to the distal 4 phalanx

Flexion of:
Wrist
Metacarpal-phalangeal joint
1st and 2nd interphalangeal joints

Front 45

Flexor pollicis longus (which layer?)

Back 45

[3rd layer]

From anterior radial shaft and interosseous membrane to the distal thumb phalanx

Flexion of:
Wrist
Carpal-metacarpal
Metacarpal-phalangeal
Interphalangeal joints of the thumb

Front 46

Pronator quadratus (which layer?)

Back 46

4th layer

Distal end of ulna to distal end of radius

Pronation

Front 47

Muscle tendons pass through X in tubes of Y membrane.

When Y membranes are inflamed --> carpal tunnel syndrome

Back 47

Muscle tendons pass through carpal tunnels in tubes of synovial membrane (provides a slippery surface).

When synovial membrane is inflamed --> CTS

Front 48

Thenar muscle group

Back 48

By the thumb

Front 49

Hypothenar muscle group

Back 49

On medial side of palm, opposite of thumb

Front 50

Interossei muscles

Back 50

Reach towards proximal phallanges, allow for adduction and abduction of phallanges

Front 51

Lumbricals

Back 51

Allow for waving motion

Flexion of the metacarpal/phalangeal joint
+
Extension of interphalangeal joint

Front 52

External intercostals move with ____-ation and pull ribs up/down

Back 52

External intercostals (connect rib above to rib below) pull ribs up for inhalation

Front 53

Internal intercostals move with ____-ation and pull ribs up/down

Back 53

Internal intercostals (connect from rib below to rib above) pull ribs down for exhalation

Front 54

Inguinal ligament

Back 54

Separates abdominal from thigh, edge of the aponeurosis

Front 55

External abdominal oblique position and action

Back 55

From ribs to inguinal ligament & illiac crest

Flexion, lateral flexion (tilt to one side), rotation of trunk

Front 56

Internal abdominal oblique position and action

Back 56

Fiber direction is perpendicular to external
Goes from iliac crest to inferior ribs

Flexion, lateral flexion (tilt to one side), rotation of trunk

Front 57

Transverse abdominalis

Back 57

From iliac crest to linea alba

Also compresses abdomen, aids with exhalation

No other movement but contracts for bowel movements

Front 58

Rectus abdominis

Why are they in short segments?

Back 58

Pubis bone to xiphoid process

Trunk flexion

They're in short segments to make one long muscle because short muscles generate more force than long muscles