Muscles of the Glenohumeral Joint

Question 1

What are the muscles of the glenohumeral joint?

Answer 1

Deltoid
Coracobrachialis
Pectoralis Major
Latissimus Dorsi
Teres Major
Rotator Cuff Group
- Supraspinatus
- Infraspinatus
- Teres Minor
- Subscapularis

Question 2

What is origin, insertion and actions of Deltoid?

Answer 2

O : Lateral clavicle, acromion process and spine of scapula
I : Deltoid tuberosity of humerus
A :
1. Abducts the arm at the GH joint
2. Flexes the arm at the GH joint
3. Medially rotates the arm at the GH joint
4. Horizontally flexes the arm at the GH joint
5. Extends the arm at the GH joint
6. Laterally rotates the arm at the GH joint
7. Horizontally extends the arm at the GH joint

Question 3

What is the origin, insertion and actions of Coracobrachialis?

Answer 3

O : Coracoid process of the scapula
I : Medial shaft of the humerus
A :
1. Flexes the arm at the GH joint
2. Adducts the arm at the GH joint

Question 4

What is the origin, insertion and actions of Pectoralis Major?

Answer 4

O : Medial clavicle, sternum and costal cartilages of ribs 1-7
I : Lateral lip of the bicipital groove of the humerus
A :
1. Flexes the arm at the GH joint
2. Adducts the arm at the GH joint
3. Medially rotates the arm at the GH joint
4. Extends the arm at the GH joint

Question 5

What is the origin, insertion and actions of Latissimus Dorsi?

Answer 5

O : Spinous Processes of T7-L5, posterior sacrum and posterior iliac crest
I : Medial lip of the bicipital groove of the humerus
A :
1. Medially rotates the arm at the GH joint
2. Adducts the arm at the GH joint
3. Extends the arm at the GH joint

Question 6

What is he origin, insertion and actions of Teres Major?

Answer 6

O : Inferior angle and inferior lateral border of scapula
I : Medial lip of the bicipital groove of the humerus
A :
1. Medially rotates the arm at the GH joint
2. Adducts the arm at the GH joint
3. Extends the arm at the GH joint

Question 7

What is the origin, insertion and actions of Supraspinatus?

Answer 7

O : Supraspinous Fossa of the scapula
I : Greater tubercle of the humerus
A :
1. Abducts the arm at the GH joint
2. Flexes the arm at the GH joint

Question 8

What is the origin, insertion and actions of Infraspinatus?

Answer 8

O : Infraspinous fossa of the scapula
I : Greater tubercle of the humerus
A : Laterally rotates the arm at the GH joint

Question 9

What is the origin, insertion and actions of Teres Minor?

Answer 9

O : Superior lateral border of the scapula
I : Greater tubercle of the humerus
A : Laterally rotates the arm at the GH joint

Question 10

What is the origin, insertion and actions of Subscapularis?

Answer 10

O : Subscapular fossa of the scapula
I : Lesser tubercle of the humerus
A : Medially rotates the arm at the GH joint