Glenohumeral Joint Muscles

Question 1

What muscles contribute to glenohumeral medial rotation? Origins and insertions?

Answer 1

Teres Major - Origin @ the posterior aspect of the inferior angle of the scapula and inserts @ the crest of the lesser tubercle

Subscapularis - Origin @ the anterior (subscapular surface) of the scapula and inserts @ the lesser tubercle of the humorous

Pectoralis Major - Origin @ the anterior aspect of the clavicle, sternocostal head, manubrium, sternal body, the true ribs and their costal cartilages, and the abdominal part: external oblique aponeurosis. Inserts @ the crest of the greater tubercle of the humerus

Anterior Deltoid - Origin @ the distal one third of the clavicle and inserts @ the humeral/deltoid tuberosity

Latissimus Dorsi - Origin @ the spinous processes of T7-T12, spinous processes of L1-L5 via thoracolumbar fascia, 9th-12th ribs and the iliac crest. Inserts @ the floor of the intertubercular groove of the humerus

Question 2

What are the muscles that contribute to glenohumeral lateral rotation? Origins and insertions?

Answer 2

Teres Minor - Origin @ the posterior aspect of the superior half of the lateral border of the scapula and inserts @ the greater tubercle of the humerous

Infraspinatus - Origin @ the infraspinatus fossa of the scapula and inserts @ the greater tubercle of the humerous

Posterior Deltoid - Origin @ the spine of the scapula and inserts @ the deltoid/humeral tuberosity

Question 3

What are the muscles contributing to glenohumeral abduction? Origins and insertions?

Answer 3

Supraspinatus - Origin @ the supraspinatus fossa and inserts @ the greater tuberosity of the humerous

Middle Deltoid - Origin @ the acromion of the scapula and inserts @ the deltoid tuberosity

Question 4

What are the muscles that contribute to glenohumeral adduction? Origins and insertions?

Answer 4

Teres Major - Origin @ the posterior surface of the inferior angle of the scapula and inserts @ the crest of the lesser tubercle

Latissimus Dorsi - Origin @ the spinous processes of T7-T12, spinous processes of L1-L5 via thoracolumbar fascia, 9th-12th ribs and the iliac crest. Inserts @ the floor of the intertubercular groove of the humerus

Pectoralis Major - Origin @ the anterior aspect of the clavicle, sternal body, manubrium, costal cartilages of the true ribs, and the abdominal part: external abdominal oblique aponeurosis. Inserts @ the crest of the greater tubercle of the humerus

Question 5

What muscles contribute to glenohumeral transverse abduction? Origins and insertions?

Answer 5

Posterior deltoid - Origin @ the spine of the scapula and inserts @ the humeral/deltoid tuberosity

Teres minor - Origin @ the posterior aspect of the superior half of the lateral border of the scapula and inserts @ the greater tubercle of the humerus

Infraspinatus (smaller role) - Origin @ the infraspinatus fossa of the posterior aspect of the scapula and inserts @ the greater tubercle of the humerus

Question 6

What muscles contribute to glenohumeral transverse adduction? Origins and insertions?

Answer 6

Anterior deltoid - lateral one-third of the clavicle and inserts @ the humeral/deltoid tuberosity

Pectoralis Major - Origin @ the anterior aspect of the clavicle, sternal body, manubrium, costal cartilages of the true ribs, and the abdominal part: external abdominal oblique aponeurosis. Inserts @ the crest of the greater tubercle of the humerus

Coracobrachialis - Origin @ the coracoid process of the scapula and inserts @ the middle one-third of the medial aspect of the humerus

Question 7

What muscles contribute to glenohumeral flexion? Origins and insertions?

Answer 7

Anterior deltoid - Origin @ the lateral one-third of the clavicle and inserts @ the humeral/deltoid tuberosity

Coracobrachialis - Origin @ the coracoid process of the scapula and inserts @ the middle one-third of the medial aspect of the humerus

Pectoralis Major - Origin @ the anterior aspect of the clavicle, sternal body, manubrium, costal cartilages of the true ribs, and the abdominal part: external abdominal oblique aponeurosis. Inserts @ the crest of the greater tubercle of the humerus

Long Head of Biceps Brachii - Origin @ the supraglenoid tubercle of the scapula, runs over the joint through the intertubercle groove and inserts @ the radial tuberosity

Short Head of Biceps Brachii - Origin @ the coracoid process of the scapula and inserts @ the radial tuberosity

Question 8

What are the muscles that contribute to glenohumeral extension? Origins and insertions?

Answer 8

Latissimus Dorsi - Origin @ the spinous process of T7-T12, spinous processes of L1-L5 via thoracolumbar fascia, 9th-12th ribs and the iliac crest. Inserts @ the floor of the intertubercular groove

Posterior Deltoid - Origin @ the spine of the scapula and inserts @ the humeral/deltoid tuberosity

Long Head of Triceps Brachii - Origin @ the infraglenoid tubercle of the scapula and inserts @ the olecranon of the ulna and adjacent antebrachial fascia

Question 9

What are the muscles that make up the rotator cuff?

Answer 9

Posterior:

• Supraspinatus
• Infraspinatus
• Teres Minor

Anterior:

• Subscapularis

Question 10

What is the role of the rotator cuff muscles? What do these muscles have in common?

Answer 10

• The rotator cuff provides active stability required due to the mobile structure of the glenohumeral joint
• These muscles hold the humerus in the glenoid fossa
• Control arthrokinematics (movement of joint surfaces)
• They are the agonists of rotation movements

They all: Insert around the humeral head and their main action is to medially/laterally rotate the humerus