Posterior Trunk Muscles

Question 1

What are the posterior trunk muscles?

Answer 1

• Erector spinae
• Trapezius
• Deltoid
• Latissimus dorsi

Question 2

What are the movements of erector spinae?

Answer 2

Vertical rotation

Lumbar extension

Question 3

What are the attachments of the erector spinae?

Answer 3

• Origin: sacrum, erector spinae aponeurosis and iliac crest

- Inserts: spinous processes T1 and T2 vertebrae and cervical vertebrae

Question 4

What are the movements of trapezius?

Answer 4

Tilt and turn head and neck, shrug, rotation of arms

Question 5

What are the attachments of the trapezius?

Answer 5

• Origin: occipital bone, ligamentum niche and spinous processes of T1-T12
• Inserts: lateral 3rd of clavicle as well as acromion and scapular spine

Question 6

What are the movements of deltoid?

Answer 6

Flexion and medial rotation of arm (pulls humerus towards clavicle)
Abduction of arm

Question 7

What are the attachments of the deltoid?

Answer 7

• Origin: from lateral part of clavicle and spine and acromion processes of scapula
• Inserts: deltoid tuberosity of humerus

Question 8

What are the movements of latissimus dorsi?

Answer 8

• Extension, adduction, transverse extension, flexion from an extended position and medial rotation of shoulder joint

Question 9

What are the attachments of latissimus dorsi?

Answer 9

• Origin: spinous processes T7-T12, thoracolumbar fascia, iliac crest, ribs 9-12 and inferior angle of scapula
• Inserts: floor of inter tubercular groove of humerus