Muscle OIA's

Question 1

Pectoralis Major

Answer 1

O: medial clavicle, sternum, and costal cartilages of the ribs
I: inter-tubercular groove-lateral lip
A: flexes the shoulder, adducts and medially rotates the humerus

Question 2

Pectoralis Minor

Answer 2

O: ribs 3-5
I: coracoid process of the scapula
A: pulls scapula anteriorly and inferiorly / if scapula is fixed, elevates ribs

Question 3

Trapezius

Answer 3

O: Superior nuchal line, external occipital protuberance, ligamentium niche, spinous processes of C7 and all thoracic vertebrae
I: lateral clavicle, acrimonious process and spine of the vertebrae
A: adducts scapula, elevates and rotates shoulder upward / if scapula is fixed, draws the head backward (hyperextends)

Question 4

Latissimus Dorsi

Answer 4

O: lower thoracic and lumbar vertebrae and lumbodorsal fascia (thoracolumbar fascia / aponeurosis)
I: Inter-tubercular groove
A: extends the shoulder, adducts and medially rotates the humerus

Question 5

Serratus Anterior

Answer 5

O: anterior superior surface of the first 8 or 9 ribs
I: anterior surface of vertebral border of scapula
A: holds scapula to chest wall, rotates scapula so shoulder moves upward

Question 6

Rhomboids Major

Answer 6

O: spinous process of C7 and T1 vertebrae
I: vertebral border of scapula at base of spine
A: adducts scapula, rotates the scapula so shoulder moves downward

Question 7

Deltoid

Answer 7

O: lateral clavicle, acrimonion process and sine of scapula
I: deltoid tuberosity
A: flexes and extends shoulder; abducts humerus

Question 8

Rotator Cuff Mnemonic

Answer 8

SITTS

• Supraspinatus
• Infraspinatus
• Teres Minor
• Teres Major
• Subscapularis

Question 9

Supraspinatus

Answer 9

O: supraspinous fossa
I: greater tubercle of the humerus
A: abducts the humerus

Question 10

Infraspinatus

Answer 10

O: infraspinous fossa
I: greater tubercle of the humerus
A: laterally rotates the humerus

Question 11

Teres Minor

Answer 11

O: axillary border of scapula above teres major
I: greater tubercle of the humerus
A: laterally rotates the humerus

Question 12

Teres Major

Answer 12

O: inferior axillary border of scapula
I: intertubercular groove (medial lip)
A: extends the shoulder, adducts an medially rotates humerus

Question 13

Subscapularis

Answer 13

O: subscapular fossa
I: lesser tubercle of humerus
A: adducts and medially rotates the humerus

Question 14

Triceps

Answer 14

(Three Heads)
O: below the glenoid fossa (long head) and posterior shaft of the humerus (other 2 heads)
I: olecranon process of the ulna
A: extends shoulder and elbow

Question 15

Biceps Brachii

Answer 15

(Two Heads)
O: coracoid process (short head) and above the glenoid fossa (long head)
I: radial tuberosity
A: extends shoulder and elbow, supinates forearm and hand

Question 16

Coracobrachialis

Answer 16

O: coracoid process of the scapula
I: proximal medial humerus
A: flexes shoulder and adducts the humerus

Question 17

Brachialis

Answer 17

O: distal anterior surface of the humerus
I: coronoid process of the ulna
A: flexes elbow

Question 18

Brahioradialis

Answer 18

O: ridges superior to the lateral epicondyle of the humerus
I: radial styloid process
A: flexes elbow

Question 19

Pronator Teres

Answer 19

O: medial epicondyle of the humerus
I: lateral surface of the mid shaft of the radius (distal of the insertion of the supinator
A: pronates forearm and hand, flexes elbow

Question 20

Flexor Carpi Radialis

Answer 20

O: medial epicondyle of the humerus
I: base of the 2nd and 3rd metacarpals - anterior aspect
A: flexes elbow, flexes and abducts wrist

Question 21

Palmaris Longus

Answer 21

O: medial epicondyle of the humerus
I: palmar aponeurosis
A: tenses palmar aponeurosis, flexes elbow and wrist

Question 22

Flexor Digitorum Superficialis

Answer 22

O: medial epicondyle of the humerus, coronoid process of ulna and proximal radius
I: medial phalanges of digits 2-5
A: flexes all joints, except distal, of all fingers; flexes wrist and elbow

Question 23

Flexor Carpi Ulnaris

Answer 23

O: medial epicondyle of the humerus
I: base of 5th metacarpal - anterior aspect, pisiform, hamate
A: flexes elbow, flexes and adducts wrist

Question 24

Flexor Digitorum Profundus

Answer 24

O: anterior medial surface of the proximal ulna
I: distal phalanges of digits 2-5
A: flexes all joints (including distal) of all fingers, flexes wrist

Question 25

Pronator Quadratus

Answer 25

O: distal anterior ulna
I: distal anterior radius
A: pronates forearm and hand

Question 26

Flexor Pollicis Longus

Answer 26

A: flexes pollex

Question 27

Extensor Carpi Radialis Longus

Answer 27

O: ridge superior to the lateral epicondyle of the humerus
I: base of second metacarpal - posterior aspect
A: extends elbow, extends and abducts wrist

Question 28

Extensor Carpi Radialis Brevis

Answer 28

O: lateral epicondyle of the humerus
I: base of the 3rd metacarpal
A: extends elbow, extends and abducts wrist

Question 29

Extensor Digitorum

Answer 29

O: lateral epicondyle of the humerus
I: posterior surfaces of the phalanges of digits 2-5
A: extends elbow, extends and abducts wrist

Question 30

Extensor Digitorum

Answer 30

O: lateral epicondyle of the humerus
I: base of the 5th metacarpal - posterior aspect
A: extends elbow, extends and adducts wrist

Question 31

Extensor Indicus

Answer 31

A: extends the second digit

Question 32

Extensor Pollicis Longus

Answer 32

A: extends pollex, abducts wrist

Question 33

Extensor Pollicis Brevis

Answer 33

A: extends pollex, abducts wrist

Question 34

Abductor Pollicis Longus

Answer 34

A: abducts pollex

Question 35

Supinator

Answer 35

O: proximal posterior ulna, lateral epicondyle of the humerus
I: lateral surface of the radius distal to the radial tuberosity (proximal to pronator teres)
A: supinates forearm and hand

Question 36

Palmar Interossei

Answer 36

A: adducts fingers

Question 37

Dorsal Interossei

Answer 37

A: abducts the fingers

Question 38

Lumbricals

Answer 38

A: flex the metacarpophalangeal (MCP) joints, extend the interphalangeal joints

(Numbered 1-4 starting with the index finger)