Intrinsic Back Muscle

Question 1

O: -posterior aspect of iliac crest

• post aspect of sacrum
• sacroiliac ligaments
• sacral & inf lumbar spinous process
• thoracolumbar fascia

I: post surface of ribs, SP & TVP of thoracic and cervical vert, post surface.

A: Extension (C&L)
Ipsilateral (C&L)

Answer 1

Erector spinae

Question 2

O: SP of C7-T3

I: ribs 1-4

A: elevate ribs 1-4 (part of inhaling)

FD: inferiolateral

Answer 2

Serratus posterior superior

Question 3

O: inf 1/2 of nuchal lig, SP of c7-T4

I: sup nuchal line, mastoid process

A: bi- extend head and neck

Uni- rotate, lat flex to same side

Answer 3

Splenius capitis

Question 4

O: sp of T3-T6

I: TVP of C1-C3

A: bi- extend head and neck

Uni- rotate & lat flex to same side

Answer 4

Splenius cervicis

Question 5

O: SP of T11/12-L3

I: ribs 9-12

A: depress 9-12 exhalation

FD: lateral

Antagonist to itself

Answer 5

Serratus posterior inferior