Lecture 14

Question 1

What movements occur at the shoulder?

Answer 1

Flexion/extension
Adduction/abduction
Medial rotation/lateral rotation
Circumduction

Question 2

What are the three true bi articular (synovial) joints of the shoulder?

Answer 2

Sternoclavicular

Acromioclavicular

Glenohumeral

Question 3

What are the two physiological (functional) joints of the shoulder?

Answer 3

Subdeltoid - allows supraspinatus to do abduction.

Scapulothoracic - keeps scapula sitting against rib cage.

Question 4

What movements occur at the sternoclavicular joint?

Answer 4

Elevation/depression

Rotraction/protraction

Question 5

What is the blood supply for the sternoclavicular joint?

Answer 5

Internal thoracic

Suprascapular

Question 6

What is the shoulder complex made up of?

Answer 6

The pectoral girdle (manubrium of sternum, clavicle, scapula)

The humerus

Question 7

What is the nerve supply to the sternoclavicular joint?

Answer 7

The subclavius nerve

Question 8

Which has more severe consequences and why - an anterior shoulder subluxation or a posterior subluxation?

Answer 8

Posterior

Subclavian and carotid arteries

Question 9

What is the blood supply of the acromioclavicular joint?

Answer 9

The suprascapular and thoracoacromial arteries.

Question 10

What is the nerve supply of the acromioclavicular joint?

Answer 10

Supraclavicular

Lateral pectoral

Axillary

Question 11

What are the intrinsic and extrinsic ligaments of the acromioclavicular joint?

Answer 11

Intrinsic:
Acromioclavicular

Extrinsic:
Coracoclavicular
- conoid
- trapezoid

Question 12

How do the conoid and trapezoid ligaments work separately and together ?

Answer 12

Conoid: in the sagittal plane, stops vertical displacement of the clavicle, holds it down in place.
Trapezoid: in the transverse/horizontal plane, stops lateral displacement of the clavicle.

Together: provide stability to stop excessive rotation of the scapula and clavicle to prevent shoulder separation.

Question 13

Which muscles protract the shoulder?

Answer 13

Serratus anterior

Pectoralis minor

Question 14

Which muscles retract the shoulder?

Answer 14

Trapezius

Rhomboid

Question 15

Which muscles elevate the shoulder?

Answer 15

Trapezius (upper fibres)

Levator scapulae

Question 16

Which muscles depress the shoulder?

Answer 16

Serratus anterior (lower fibres)
Pectoralis minor

Question 17

Which muscles rotate the shoulder?

Answer 17

Serratus anterior

Pectoralis minor

Trapezius

Rhomboids

Question 18

What is a grade 1 acromioclavicular dislocation?

Answer 18

AC ligaments are stretched but not torn.
CC ligaments are intact.

Can be fixed conservatively by immobilising the joint.

Question 19

What is a grade 2 acromioclavicular dislocation?

Answer 19

AC ligaments torn and disrupted.
CC ligaments remain intact.

AC ligaments can be fixed.

Question 20

What is a grade 3 acromioclavicular dislocation?

Answer 20

AC and CC ligaments are ruptured.
Wide separation of joint.
Humerus sinks inferiorly to the clavicle.

Question 21

What is the blood supply of the glenohumeral joint?

Answer 21

Circumflex humeral arteries (anterior and posterior)

Question 22

What is the nerve supply of the glenohumeral joint?

Answer 22

Suprascapular
Axillary
Lateral pectoral

Question 23

What are the ligaments of the glenohumeral joint?

Answer 23

Intrinsic:
Coracohumeral
Glenohumeral (Z - superior, middle, inferior)

Extrinsic:
Coracoacromial - tight roof
Transverse humeral - holds LH of biceps tendon in bicipital groove.

Question 24

Which ligament is lax to allow your arm hang by your side?

Answer 24

The inferior glenohumeral ligament.

Question 25

What are the names of the three bursa found Im the glenohumeral joint?

Answer 25

Subscapular Subacromial Subdeltoid

Question 26

Which muscles abduct the scapula?

Answer 26

The trapezius and serratus anterior. Trapezius pulls the spine of the scapula upwards. Serratus anterior pulls the spine of the scapula outwards.

Question 27

When is the glenohumeral joint most like to dislocate?

Answer 27

When the humerus is abducted and externally rotated. The humerus makes most contact in this position. It gives maximal stability but is most exposed. Dislocates anteriorly and inferiorly.

Question 28

What movements do flexor musculature produce?

Answer 28

Flexion Adduction Medial rotation

Question 29

Which muscles make up the flexor musculature of the shoulder joint?

Answer 29

``` Pectoralis major Deltoid Biceps Coracobrachialis Teres major Latissimus dorsi Subscapularis ```

Question 30

Which muscles make up the extensor musculature of the shoulder joint?

Answer 30

``` Deltoid Teres major Latissimus dorsi Triceps Supraspinatus Infraspinatus Teres minor ```

Question 31

Which muscles contribute to abduction at the shoulder joint?

Answer 31

Deltoid | Supraspinatus

Question 32

Where is the subdeltoid physiological joint?

Answer 32

Between the supraspinatus tendon and the glenohumeral joint. Deep to deltoid. Painful arc syndrome occurs as the supraspinatus tendon doesn't have a good blood supply (necrosis).

Question 33

Where is the scapulothoracic physiological joint?

Answer 33

Between the serratus and the thorax. Between the serratus and the scapula. Scapula and humerus 1:2.

Question 34

What are some rotator cuff injuries?

Answer 34

Frozen shoulder - adhesive capsulitis, calcification restricts movement. Impingement of supraspinatus - during abduction. Rotator cuff (fixator muscles) blend with capsule of joint, pull humeral head towards glenoid and compress it.

Question 35

What is subacromial bursitis?

Answer 35

Calcification of subacromial bursa located under acromion process of the scapula. Susceptible to irritation during shoulder abduction.

Question 36

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

Answer 36

Anterior/inferior Due to the force applied to the abducted and externally rotated arm. Can be fixed.

Question 37

What type of dislocation of the glenohumeral joint is least common?

Answer 37

``` Posterior. Due to electric shock or seizures. Arm adducted and internally rotated. Head of humerus is pushed behind the glenoid cavity. Can't be fixed conservatively. ```