The Glenohumeral (Shoulder) Joint

Question 1

Glenohumeral joint classification.

Answer 1

synovial ball & socket

Question 2

The glenohumeral joint is an articulation between…

Answer 2

the head of humerus (ball) and glenoid fossa (socket) of the scapula.

Question 3

Describe the head of the humerus as an articulating surface

Answer 3

forms 2/5th of a sphere and is covered in hyaline cartilage.
It faces superiorly, medially and posteriorly

Question 4

Describe the glenoid fossa as an articular surface

Answer 4

situated at the superolateral angle of the scapula
pear-shaped, concave both vertically and transverse
faces laterally, anteriorly and slightly superiorly.

Question 5

What is the glenoid labrum and its function?

Answer 5

Fibrocartilaginous collar
deepens & expands the glenoid

Question 6

Describe the joint capsule of the glenohumeral joint

Answer 6

loose cylindrical sleeve between the two bones

Question 7

Name the attachment sites of the joint capsule of the glenohumeral joint

Answer 7

Scapula: just outside the margins of the glenoid labrum anteriorly and inferiorly, and to the glenoid labrum superiorly and posteriorly.

Humerus: anatomical neck, around the articular margins of the head, medial to the greater and lesser tubercles, except inferiorly where it joins the medial surface of the shaft about 1cm below the articular margin

Question 8

Why is the joint capsule of the glenohumeral joint loose inferiorly?

Answer 8

To allow for abduction of the arm

Question 9

The fibrous capsule is strengthened above by…

Answer 9

supraspinatus

Question 10

The fibrous capsule is strengthened bellow by…

Answer 10

Long head of triceps

Question 11

The fibrous capsule is strengthened behind by…

Answer 11

Tendons of infraspinatus & Teres minor

Question 12

The fibrous capsule is strengthened infront by…

Answer 12

tendon of subcapularis

Question 13

Name the rotator cuff muscles

Answer 13

Supraspinatus , infraspinatus , teres minor, and subscapularis

Question 14

What are the functions of the rotator cuff muscles as part of the glenohumeral joint

Answer 14

Blend with the joint capsule to form a musculotendinous sleeve that surround the glenohumeral joint.
Stabilise and holds the head of the humerus in the glenoid cavity without compromising range of movement.

Question 15

Location & function of the synovial membrane of the glenohumeral joint

Answer 15

Lines the inner surface of the capsule and covers the lower part and sides of the anatomical neck as far as the articular cartilage on the head of the bone

Question 16

Name the capsular ligaments

Answer 16

Superior, middle & inferior glenohumeral ligaments
Transverse humeral ligament

Question 17

Name the non-capsular ligaments in the glenohumeral joint

Answer 17

Coracohumeral & Coracoacromial ligaments

Question 18

Superior Glenohumeral Ligament origin

Answer 18

Upper glenoid margin

Question 19

Superior Glenohumeral Ligament insertion

Answer 19

Lesser tubercle of humerus

Question 20

How does the Superior Glenohumeral Ligament limit movement?

Answer 20

Under tension in lateral rotation

Question 21

Middle Glenohumeral Ligament origin

Answer 21

Middle glenoid margin below the superior ligament

Question 22

Middle Glenohumeral Ligament insertion

Answer 22

Lesser Tubercle of humerus

Question 23

How does the Middle Glenohumeral Ligament limit movement?

Answer 23

Under tension in lateral rotation and abduction

Question 24

Inferior Glenohumeral Ligament origin

Answer 24

Lower glenoid margin

Question 25

Inferior Glenohumeral Ligament insertion

Answer 25

Anterior part of the anatomical neck of humerus

Question 26

How does the Inferior Glenohumeral Ligament limit movement?

Answer 26

Under tension in lateral rotation and abduction

Question 27

Transverse Humeral Ligament origin

Answer 27

Greater tubercle of humerus

Question 28

Transverse Humeral Ligament insertion

Answer 28

Lesser tubercle of humerus

Question 29

How does the Transverse Humeral Ligament limit movement

Answer 29

Holds long head of Biceps Brachii in the intertubercular groove

Question 30

Coracohumeral Ligament origin

Answer 30

Coracoid process

Question 31

Coracohumeral Ligament insertion

Answer 31

Anterior part of the ligament attached to the lesser tubercle. Posterior part attaches to the greater tubercle.

Question 32

How does the Coracohumeral Ligament limit movement

Answer 32

Blends with the capsule

Question 33

Coracoacromial Ligament origin

Answer 33

Lateral border of the coracoid process

Question 34

Coracoacromial Ligament insertion

Answer 34

Anterior aspect of the acromion

Question 35

How does the Coracoacromial Ligament limit movement?

Answer 35

Limits upward migration of the humerus

Question 36

Are the articular surfaces of the glenohumeral joint congruent or incongruent?

Answer 36

The articular surfaces are incongruent.
But:
The glenoid labrum deepens and expands the fossa and makes the joint more congruent.

Question 37

What structures increase the stability of the glenohumeral joint?

Answer 37

The ‘rotator cuff’ muscles aid stability.
The tendons of the long heads of Biceps and Triceps also stabilise the joint
The coracoacromial arch resists upward displacement of the head of the humerus.

Question 38

What movements does the glenohumeral joint allow?

Answer 38

Flexion, extension
Abduction, adduction
Medial & lateral rotation

Question 39

Angle of flexion

Answer 39

110°, 180° with pectoral girdle

Question 40

Angle of extension

Answer 40

70°, 90° with pectoral girdle

Question 41

Angle of abduction

Answer 41

120°, 180º with scapular rotation

Question 42

Angle of adduction

Answer 42

120°, 180º with scapular rotation, from abducted position.

Question 43

Angle of medial rotation

Answer 43

90° +

Question 44

Angle of lateral rotation

Answer 44

80°