Shoulder - glenohumeral joint muscles (abduction and adduction)

Question 1

Name the 2 shoulder abductor muscles and identify where they are located on the human body (if unable check on Complete Anatomy)

Answer 1

Supraspinatus muscle
Acromial part of deltoid (middle)

Question 2

What is the origin, insertion and innervation of the supraspinatus muscle?

Answer 2

o Origin – Supraspinous fossa of scapula
o Insertion – Greater tubercle of humerus
o Innervation - Suprascapular nerve (C5-C6)

Question 3

What is the origin, insertion and innervation of the acromial part of deltoid muscle?

Answer 3

o Origin – Acromion of scapula
o Insertion – Deltoid tuberosity of humerus
o Innervation – Axillary nerve (C5-C6)

Question 4

Name the 4 shoulder adductor muscles and identify where they are located on the human body (if unable check on Complete Anatomy)

Answer 4

Latissimus dorsi
Pectoralis major
Teres major
Coracobrachialis

Question 5

What is the origin, insertion and innervation of the latissimus dorsi muscle?

Answer 5

o Origin – Spinous processes of T7-T12 vertebrae, spinous processes of L1-L5 vertebrae via thoracolumbar fascia, 9th-12th ribs, iliac crest
o Insertion – Floor of intertubercular sulcus of humerus
o Innervation – Thoracodorsal nerve (C6-C8)

Question 6

What is the origin, insertion and innervation of the pectoralis major muscle?

Answer 6

o Origin – Clavicular head: anterior aspects of medial half of clavicle; Sternocostal head: manubrium, sternal body, the true ribs and their costal cartilages; Abdominal part: external abdominal oblique aponeurosis
o Insertion – Crest of greater tubercle of humerus
o Innervation – Medial and lateral pectoral nerves (C5-T1)

Question 7

What is the origin, insertion and innervation of the teres major muscle?

Answer 7

o Origin - Posterior aspect of inferior angle of scapula
o Insertion – Crest of lesser tubercle of humerus
o Innervation – Lower subscapular nerve (C5-C7)

Question 8

What is the origin, insertion and innervation of the coracobrachialis muscle?

Answer 8

o Origin – Coracoid process of scapula
o Insertion – Middle thirds of medial aspect of humerus
o Innervation – Musculocutaneous nerve (C5-C7)