MSK - Shoulder Joint And Back Muscles

Question 0

What are the two superficial muscles of the back?

Answer 0

Trapezius

Latissimus dorsi

Question 1

What do the muscles of the back do?

Answer 1

Attach the limb to the trunk

Question 2

What does the trapezius do?

Answer 2

It directly attaches the pectoral girdle to the trunk
Superior fibres - elevate scapula
Middle - retracts scapula
Inferior - depresses scapula

Question 3

What does the latissimus dorsi do?

Answer 3

This is a powerful adductor - extends the arm at the shoulder
It is a medial rotator

Question 4

What does the levator scapulae do?

Answer 4

This elevates the scapula

Question 5

What does the rhomboid major do?

Answer 5

Retracts scapula and rotates it - depressing the glenoid cavity

Question 6

When is scapula rotation needed, and how does it happen?

Answer 6

It is needed for abduction of the arm above 90’ due to the acromion preventing further rotation.
The superior and inferior parts of the trapezius act together to do this

Question 7

What is the glenohumeral joint?

Answer 7

A ball and socket synovial joint between the articulating surfaces of the scapula and humerus.

Question 8

How is glenoid cavity deepened?

Answer 8

By a rim of fibrocartilage called glenoid labrum

Question 9

How is the joint lubricated?

Answer 9

Lined by synovial fluid and enclosed by fibrous capsule.

Question 10

Why is this joint particularly mobile?

Answer 10

The GC is very shallow

Question 11

What is the name of the most important ligament in the extra capsule?

Answer 11

The coraco acromial ligament

Between the acromion and the coraciod process

Question 12

What is the coraco - acromial - arch?

Answer 12

This is an osseoligamentous structure which overlies the humeral head preventing the upper displacement of the humerus.

Question 13

What are the rotator cuff muscles?

Answer 13

The supraspinatus
Infraspinatus
Teres minor
Subscapularis

Question 14

Where are the rotator cuff muscles inserted to?

Answer 14

The posterior muscles - greater tubercule

Anterior (subscapularis) - lesser tubercule

Question 15

How is the ‘cuff’ formed?

Answer 15

Tendons merge with each other and the capsule.

Question 16

What is painful arc syndrome?

Answer 16

This is when the supraspinatus tendon rubs under the CAA
this causes irritation and inflammation of the supraspinatus tendon
Results in pain during 50-130 abduction

Question 17

Which muscles are responsible for flexion of the shoulder?

Answer 17

Pectoralis major
(Anterior) Deltoid
Coracobracialis
Biceps

Question 18

Which muscles are responsible for the extension of the arm?

Answer 18

(Post) deltoid
Latissimus dorsi
Teres major

Question 19

Medial rotation of the shoulder?

Answer 19

Subscapularis
Teres major
Pectoralis major
Latissimus dorsi

Question 20

Lateral rotation of the arm?

Answer 20

Intraspinous

Teres major

Question 21

Adduction of the arm?

Answer 21

Pec major
Latissimus dorsi
Teres major

Question 22

Abduction of the arm?

Answer 22

Supraspinatus - 20’
Deltoid -20-90
Above 90 is scapula rotation by the trapezius.

Question 23

What are the main arteries supplying the shoulder joint?

Answer 23

Anterior and posterior circumflex humeral artery

Suprascapular artery

Question 24

What is the nerve supply to shoulder?

Answer 24

Suprascapular, Axillary and lateral pectoral nerves

Question 25

Which structures are vulnerable at fracture sites?

Answer 25

Axillary nerve, posterior circumflex artery.

Question 26

What is the most common direction of dislocation of the glenohumeral joint?

Answer 26

Anterior- inferior

Question 27

How is dislocation usually caused?

Answer 27

Trauma on an abducted arm

Question 28

Where is the humeral head repositioned to after dislocation?

Answer 28

Below the coraciod process

Question 29

What is a complication of a dislocated shoulder?

Answer 29

The capsule and rotator cuff may tear so poor healing leads to recurrent dislocation.

Question 30

How would you test for Axillary nerve damage after dislocation?

Answer 30

Test for sensation in the regemental badge area