1. Muscles of the Spinal Column
Chapter 12

2. Cervical Muscles

3. Splenius (capitis and cervicis)
Origin:
Cervicis – spinous process of T3-T6
Capitis - lower half of ligmentum nuchea & spinous process of C7 and T1-3.
Insertion:
Cervicis - transverse process of C1-C3.
Capitis – mastoid process and occipital bone
Actions:
Whole
Cervical Extension
Half
Cervical Rotation to the same side.
Cervical Lateral flexion

4. Splenius (cervicis & capitis)

5. Splenius

6. Sternocleidomastoid
O: Top of the sternum and medial third of the clavical
I: Mastoid process
Action:
Whole
Cervical Flexion
Half
Cervical Lateral Flexion
Cervical Rotation to the opposite side.

8. Sternocleidomastoid

9. Sternocleidomastoid

10. Scalenes (or scaleni) O: First two ribs
I: Transverse processes of cervical vertebrae.
Actions:
Whole – Cervical Flexion
Half - Cervical Lateral Flexion (help with inhalation during exercise)

12. Scalenes

13. Lumbar Muscles

14. Erector spinae muscles
O: Fascia of lower back, posterior L, T and lower C vertebrea, and angles of ribs.
Inesrtions
Spinalis branch - spinous process of T and C and occipital bone
Longissimus branch - transverse process of T and C, mastoid process.
Iliocostalis branch - angles of the ribs and cervical transverse processes
Actions:
Whole – Extension
Half - Lateral flexion

15. Erector spinae muscles

16. Erector spinae muscles
Iliocostalis branch Longissimus branch Spinalis branch

17. Spinalis branch Longissimus branch Iliocostalis branch

18. Quadratus lumborum O: Posterior lip of iliac crest
I: Lower border of 12th rib and transverse process of L1-4
Actions:
Half - Lumbar lateral flexion
Whole - Stabilization

19. Quadratus lumborum

20. Iliopsoas O: I: Lesser trochanter of femur Action:
Psoas - lateral surface of T12 and L1-5,
Iliacus - anterior surface of ilium (iliac fossa)
I: Lesser trochanter of femur
Action:
Whole - Lumbar flexion of trunk
[Whole - Hip flexion]

21. Iliopsoas

22. Iliopsoas

23. The Abdominal Muscles 4. 2. 3. 1.

24. Rectus abdominis O: Crest of the pubis
I: Xyphoid process and 5th - 7th ribs
Action:
Whole
Lumbar Flexion
Half
Lumbar lateral flexion

25. Rectus abdominis

26. External oblique O: Lower 8 ribs.
I: Anterior iliac crest; inguinal ligament, crest of pubis, fascia of the rectus abdominus
Action:
Whole – Lumbar flexion
Half
Lumbar rotation to opposite side
Lumbar lateral flexion

27. External oblique

28. External oblique

29. Internal oblique
O: Inguinal ligament (from anterior iliac crest to pubis) and iliac crest
I: Costal cartilages of the lower ribs.
Actions:
Whole – Lumbar flexion
Half
Lumbar rotation to the same side
Lumbar lateral flexion

30. Internal oblique

32. Internal
The Oblique
Muscles?
Which is Internal and which is External?
External

33. Transverse abdominis
I: Inguinal ligament, iliac crest, and lower 6 ribs
O: Linea alba ("white line") and pubis crest
Functions:
Exhalation (during exercise)

35. Transverse abdominis

36. MUSCLES OF RESPIRATION
Rib actions
Respiration

37. III. ANATOMY of the RESPIRATOY MUSCLES

38. Diaphragm O: Xiphoid process, costal cartilages, lumbar vertebrae
I: Central tendon
A: Flattens, pulls central tendon downward

39. External Intercostals
O: Inferior border of the ribs
I: Superior border of the next rib below
A: Draws ribs together and lifts the ribs
11 on each side; slant down and forward

40. Internal Intercostals (p. 379)
O: Inferior border of the ribs
I: Superior border of the next rib down
A: Draws ribs together and lowers ribs
slant down and backward

41. MUSCLES OF RESPIRATION
Inspiration
Rib (with
Intercostal
Muscles)
Diaphragm
Expiration

43. I. INSPRIATION Increase in thorasic cage Volume inside increases
Pressure decreases
Air moves into the lungs

44. A. Inspiration at Rest 1. Diaphragm
Flattens and moves downward when contracted

45. A. Inspiration at Rest 1. Diaphragm 2. External Intercostals
Flattens and moves downward when contracted
2. External Intercostals
Lift the ribs up and out when contracted

46. B. Inspiration During Exercise
1. Scalenes – elevate upper ribs
2. Sternoceidomastoid – elevate clavical and upper ribs
3. External intercostal muscles

47. II. EXPIRATION Decrease thorasic cage Volume inside decreases
Pressure increases
Air moves out of the lungs

48. A. Expiration at Rest. No muscles are involved
Passive recoil action at rest will decrease the thorasic cage

49. B. Expiration During Exercise
Internal Intercostals -
Rectus Abdominus – help push the diaphragm upward.
External obliques– help push the diaphragm upward.
Internal obliques– help push the diaphragm upward.
Transverse abdominus– help push the diaphragm upward.

50. Muslces of Expiration Muscles of Inspiration *Sternocleidomastoid
*Scalenes
*Internal Intercostals
External Intercostals
*Rectus Abdominus
Diaphragm
*External Obliques
*Internal Obliques
*Transverse Abdominus
Muscles of
Inspiration

51. Note:
These muscles need to trained with exercise as any other muscle does.
Early limitations (side aches and breathlessness) felt during exercise may involve the untrained state of these muscles.