Muscles of the Back

Question 1

Origin of Trapezius

Answer 1

Back of the Skull: 
- External Occipital Protuberance
- Superior Nuchal Line
Back of the Neck:
- Ligamentum Nuchae
- Spine of C7
Back of Thorax:
- Spine of all thoracic vertebra
- Supraspinous Ligament

Question 2

Insertion of Trapezius

Answer 2

Clavicle: posterior border of lateral third “upper”
Scapula: medial border of acromion “middle”
upper border of spinal crest “lower”

Question 3

Nerve Supply of Trapezius

Answer 3

Motor: Spinal Accessory
Sensory: C3 , C4

Question 4

Action of Trapezius

Answer 4

Upper Fibres: Shoulder shrug
Middle Fibres: Retraction of the scapula
Lower Fibres: Depression of the shoulder
Upper and Lower Fibres: Rotation of the scapula (arm is raised above the head)

Question 5

Origin of Latissimus Dorsi

Answer 5

• Spinous processes of T7-T12
• Supraspinous Ligament
• Thoracolumbar Fascia
• Outer lip of iliac crest
• Inferior 3 or 4 ribs
• Inferior angle of the scapula

Question 6

Insertion of Latissimus Dorsi

Answer 6

Floor of Bicipital Groove of the humerus

Question 7

Nerve Supply of Latissimus Dorsi

Answer 7

Thoracodorsal (C6, C7, C8)

Question 8

Action of Latissimus Dorsi

Answer 8

• Adduction
• Medial Rotation
• Extension
• Climbing & Swimming (when insertion is fixed)
• Accessory inspiratory

Question 9

Origin of Levator Scapula

Answer 9

Transverse processes of C1- C4

Question 10

Insertion of Levator Scapula

Answer 10

Superior angle, medial border, dorsal scapula

Question 11

Nerve Supply of Levator Scapula

Answer 11

Dorsal scapular nerve (C5)

Question 12

Action of Levator Scapula

Answer 12

Elevates Scapula

Question 13

Origin of Rhomboideus Minor

Answer 13

• Nuchal Ligament

- Spinous Processes of C7 to T1

Question 14

Insertion of Rhomboideus Minor

Answer 14

Medial border, dorsal scapula

Question 15

Nerve Supply of Rhomboideus Minor

Answer 15

Dorsal scapular nerve (C5)

Question 16

Action of Rhomboideus Minor

Answer 16

Retracts and rotates scapula

Question 17

Origin of Rhomboideus Major

Answer 17

Spinous Processes of T2-T5

Question 18

Insertion of Rhomboideus Major

Answer 18

Medial border, dorsal scapula

Question 19

Nerve Supply of Rhomboideus Major

Answer 19

Dorsal Scapular Nerve (C5)

Question 20

Action of Rhomboideus Major

Answer 20

Retracts and rotates scapula