Glenohumeral Joint

Question 1

Classify the joint according to structure and function.

Answer 1

Structure - synovial joint; function - ball and socket joint.

Question 2

What are the articulating surfaces of the glenohumeral joint?

Answer 2

Glenoid cavity of scapula + head of humerus.

Question 3

How is stability achieved in the glenohumeral joint?

Answer 3

Glenoid labrum, joint capsule, ligaments, rotator cuff muscles, biceps tendon.

Question 4

What are the ligaments of the glenohumeral joint?

Answer 4

Glenohumeral ligaments, coracohumeral ligament, transverse humeral ligament, coracoclavicular ligament, coracoacromial ligament.

Question 5

Where is the glenohumeral ligament and what is its role?

Answer 5

From humerus to glenoid fossa, prevents anterior dislocation by supporting anteriorly.

Question 6

Where is the coracohumeralligament and what is its role?

Answer 6

Base of coracoid process to greater tubercle of humerus, supports superiorly.

Question 7

Where is the transverse humeral ligament and what is its role?

Answer 7

Between two tubercles of humerus, holds tendon of long head of the biceps in intertubercular groove.

Question 8

Where is the coracoclavicular ligament?

Answer 8

From clavicle to coracoid process.

Question 9

Where is the coracoacromial ligament and what is its role?

Answer 9

Acromion and coarcoid process to make coracoacromial arch so prevent superior dislocation.

Question 10

What are the rotator cuff muscles?

Answer 10

Subscapularis, supraspinatus, infraspinatus, teres minor.

Question 11

What are the actions of the glenohumeral joint?

Answer 11

Flexion, extension, abduction, adduction, internal rotation, external rotation.

Question 12

What are the muscles powering flexion of the glenohumeral joint?

Answer 12

Deltoid, latissimus dorsi, teres major.

Question 13

What are the muscles powering extension of the glenohumeral joint?

Answer 13

Pectoralis major, anterior deltoid, caroacobrachialis.

Question 14

What are the muscles powering abduction of the glenohumeral joint?

Answer 14

0-15 degrees - supraspinatus
15-90 degrees - middle deltoid
90+ degrees - serratus anterior and trapezius to rotate scapula

Question 15

What are the muscles powering adduction of the glenohumeral joint?

Answer 15

Pectoralis major, latissimus dorsi, teres major.

Question 16

What are the muscles powering internal rotation of the glenohumeral joint?

Answer 16

Subscapularis, pectoralis major, latissimus dorsi, teres major, anterior deltoid.

Question 17

What are the muscles powering external rotation of the glenohumeral joint?

Answer 17

Infraspinatus, teres minor.

Question 18

Which arteries supply the glenohumeral joint?

Answer 18

Anterior and posterior circumflex humeral arteries, suprascapular artery, branch of thyrocervical trunk.

Question 19

Which nerves innervate the glenohumeral joint?

Answer 19

Axillary, suprascapular, lateral pectoral nerves.

Question 20

What is impingement syndrome?

Answer 20

Thickening of coracacromial ligament which leads to impingement.

Question 21

What is the mechanism of injury resulting in anterior glenohumeral dislocation?

Answer 21

Excessive extension and external rotation of humerus.

Question 22

What is a complication of glenohumeral anterior dislocation?

Answer 22

Axillary nerve damage leading to deltoid paralysis and loss of sensation over the regimental badge area.

Question 23

What is rotator cuff tendonitis?

Answer 23

Inflammation of muscle tendons due to overuse leading to degenerative changes.

Question 24

What is painful arc syndrome?

Answer 24

Pain on abduction between 60-120 degrees.