Muscles of the Spine

Question 1

What are the origins and insertions of trapezius?

Answer 1

O: Medial 1/3rd superior nuchal line of occipital bone, external occipital protuberance, ligamnetum nuchae, C7-T12 spinous processes and supraspinous processes

I: Upper Fibres - posterior border of lateral 1/3rd clavicle.

Middle fibres - medial margin of acromion & superior lip of crest of spine of scapula.

Lower fibres - tubercle at medial end of spine of scapula

Question 2

what is the nerve supply for trapezius

Answer 2

spinal acessory nerve - C2, C3, C4

Question 3

what is the action of trapezius?

Answer 3

upper fibres - elevate shoulder girdle, extend Cx spine bilaterally & side flexion of Cx spine unilaterally (with ROI)

middle fibre - retract shoulder girdle

lower fibres - depress shoulder girdle

together - cause lateral rotation of scapula

Question 4

What is the function of trapezius?

Answer 4

Upper fibres- looking at ceiling

Middle fibres - pulling a plinth towards you

Lower fibre - pushing up out of chair

Question 5

what are the attachments of sternomastoid?

Answer 5

O: sternal head - anterior surface of manubrium, clavicular head - upper surface of medial third of clavicle

I: mastoid process and lateral third of superior nuchal line

Question 6

nerve supply to sternomastoid?

Answer 6

cranial accessory nerve 11

anterior primary rami C2 and C3

Question 7

what is the action of sternomastoid?

Answer 7

flexion, lateral flexion to the same side and rotation to the opposite side

Question 8

Functional activity of sternomastoid

Answer 8

lifting head up from lying