Extensor Compartment of Upper Limb/Back Muscles

Question 1

Relative Relation of Trapezius and Rhomboids

Answer 1

Rhomboids are deep to trapezius

Question 2

What are the two rhomboid muscles

Answer 2

Rhomboid Major and Minor

Question 3

Origin of Rhomboids

Answer 3

Minor: Spinous Processes C7-T1
Major: Spinous Processes T2-T5

Question 4

Insertion of Rhomboids

Answer 4

Minor: Medial Border of Scapula at level of Spine
Major: Medial Border of Scapula between spine and inferior angle

Question 5

Innervation of Rhomboids

Answer 5

Dorsal Scapular Nerve C5

Question 6

Name the Rotator Cuff Muscles

Answer 6

SITS
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis

Question 7

Functions of the Rotator Cuff

Answer 7

Medial/Lateral Rotation of the Shoulder

Supraspinatus does not rotate but instead plays a more important role of stabilising the joint and keeping it in its joint

**THEY FORM A MUSCULOTENDENOUS CUP AROUND GLENOHUMERAL JOINT

Question 8

What is another term for medial rotation

Answer 8

Internal Rotation

**Lateral aka External

Question 9

Which Shouldrr Rotator Cuff muscles are medial rotators and which are lateral rotators

Answer 9

Medial Rotation - Subscapularis

Lateral Rotation - Teres Minor & Infraspinatus

Question 10

What muscular movement does the supraspinatus support

Answer 10

Initiation of Abduction

Question 11

Which Triceps Brachii head is hardest to see and why

Answer 11

Medial head as it is under Triceps Aponeurosis

Question 12

For Triceps Brachii Insertion/Origin/Innervation

GO TO INTRODUCTION TO ARM LECTURE

Question 13

What 2 structures run in the radial groove

Answer 13

Radial Nerve

Deep Artery of the Arm/Deep Brachial Artery/Profunda Brachii Artery

Question 14

Which Muscles insert at the intertubercular sulcus

Answer 14

Teres Major
Pec Major

Latissimus Dorsi

**THE LONG HEAD OF BICEPS BRACHII IS WEDGED HERE BUT DOES NOT ATTACH

Question 15

Boundaries of the Quadrangular Space

Answer 15

Teres Minor
Teres Major
Humerus
Triceps Long Head

Question 16

Contents of Quadrangular Space

Answer 16

Axillary nerve

Posterior Humeral Circumflex Artery

Question 17

Effect of Shoulder Dislocation on Quadrangular space

Answer 17

Shoulder can pop down into quadrangular space and damage the axillary nerve

Question 18

Origin of Teres Major & Teres Minor

Answer 18

Teres Minor: Lateral Border of Scapula

Teres Major: Inferior/Lateral Border of Scapula

Question 19

Insertion of Teres Major & Minor

Answer 19

Teres Minor: Greater Tubercle of Humerus

Teres Major: Intertubercular Sulcus

Question 20

Superficial Muscles of Posterior Forearm

Answer 20

Brachioradialis
ECRL
ECRB
ED
EDM
ECU

**DONT ACTUALLY HAVE TO MEMORISE THESE JUST BE AWARE

Question 21

Why is the brachioradialis different to other muscles on the posterior forearm

Answer 21

It is the only muscle in this compartment that is not responsible for Extension and instead plays a role in forearm flexion (When semi pronated)

**It is a weak flexor but a flexor none the less

Question 22

Origin of Brachioradialis

Answer 22

Lateral Supracondylar Ridge of Humerus

Question 23

Insertion of Brachioradialis

Answer 23

Styloid Process of Radius

Question 24

Innervation of Brachioradialis

Answer 24

Radial Nerve

Question 25

Important Landmark Relations of Brachioradialis

Answer 25

It forms the lateral boundary of the cubital fossa

Radial Nerve passes deep to it

Question 26

Deep Muscles of Posterior Forearm

Answer 26

APL
EPB
EPL

Extensor Indicis

((Supinator as well))

Question 27

Why is the supinator muscle not very clinically relevant

Answer 27

Because it is so deep

Question 28

Contents of the Anatomical Snuff Box

Answer 28

Radial Artery
Superficial Branch of Radial Nerve
Cephalic Vein

Question 29

Floor of Anatomical Snuff Box

Answer 29

Scaphoid and Trapezium

Question 30

What are the outcrop muscles

Answer 30

APL
EPB
EPL

Question 31

Why are the outcrop muscles named such

Answer 31

They emerge (crop out) from a furrow in the lateral part of the forearm that divides the extensors

Question 32

Origin of EPB

Answer 32

Posterior Distal 1/3 of Radius

Question 33

Origin of EPL

Answer 33

Posterior Middle 1/3 of Ulna

**THINK OF LOCATION ON ANATOMICAL SNUFF BOX AND ALSO THAT IT IS LONGER THAN EPB - THUS IT IS ON ULNA AND MORE PROXIMAL

Question 34

Origin of APL

Answer 34

Interosseous Membrane and adjacent posterior surfaces of proximal halves of Ulna/Radius

Question 35

Insertion of EPB

Answer 35

Posterior Base of Proximal Thumb Phalynx

Question 36

Insertion of EPL

Answer 36

Posterior Base of Distal Thumb Phalynx

Question 37

Insertion of APL

Answer 37

Posterior Base of Metacarpal 1

Question 38

Function of Retinaculum

Answer 38

Preventing the Bowstringing of Tendons

Question 39

Extensor Expansion

Answer 39

The flattening and widening of extensor digitorum muscles at the dorsal aspect of the phalanges

Question 40

Effect of Injury to Radial Nerve at Radial Groove on Triceps Brachii and Why

Answer 40

Only Medial Head is likely to be weakened since it originates below the radial groove while the lateral and long head originate superior to it

Question 41

Insertions of Lumbricals

Answer 41

Extensor Expansion of Hand

Question 42

Insertions of Palmar Interossei

Answer 42

1: Extensor Expansion of Digit 2

2 & 3: Extensor Expansion of Digits 4 & 5

Question 43

Insertions of Dorsal Interossei

Answer 43

1 & 2: Extensor Expansions of Digits 2 & 3

3 & 4: Extensor Expansions of Digits 3 & 4

Question 44

What are the common actions of Lumbricals & Dorsal/Palmar Interossei

Answer 44

Flexion at the Metacarpophalangeal Joints

Extension at the Interphalangeal Joints

Question 45

Answer 45

1 - Triceps Brachii Long Head
2 - Teres Minor
3 - Teres Major

X - Axillary Nerve/Posterior Humeral Circumflex Artery

Question 46

Role of Latissimus Dorsi

Answer 46

Arm Medial Rotation
Arm Adduction
Arm Extension