1. Chapter 9:Part 1 The Spinal Column and Thorax
KINESIOLOGY
Scientific Basis of Human Motion, 12th edition
Hamilton, Weimar & Luttgens
Presentation Created by
TK Koesterer, Ph.D., ATC
Humboldt State University
Revised by Hamilton & Weimar
McGraw-Hill/Irwin
Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.

2. Objectives
1. Name, locate, & describe the structure & ligamentous reinforcements of the joints of the spinal column. 2. Name & demonstrate movements possible. 3. Name & locate muscles & muscle groups, and name their primary actions. 4. Analyze the fundamental movements with respect to joint & muscle actions. 5. Describe common injuries.

3. SPINAL COLUMN: Structure
Fig 9.1
(7)
(12)
(5)
7 Cervical Vertebrae
12 Thoracic Vertebrae
5 Lumbar Vertebrae
Sarcrum
Coccyx

4. Articulation of Vertebral Bodies
Cartilaginous joint.
Intervertebral discs of fibrocartilage.
Outer fibrous rim (annulus fibrosus).
Nucleus pulposus
Permits compression in any direction & some torsion.
Shock absorbers.
Fig 9.2

5. Ligamentous Reinforcement
Anterior longitudinal ligaments.
Posterior longitudinal ligament.
Fig 9.3a & 9.4a

6. Articulation of Vertebral Arches
Facets are nonaxial.
Enclosed in a capsule.
Permit gliding.
Motion determined by the direction that the facets face.
Motion between vertebrae only a few degrees.
Cummulative motion from 40º to 70°.
Fig 9.5

7. Articulation of Vertebral Arches: Cervical
Slant at about 45°
Favors rotation & lateral flexion.
Movements are flexion & hyperextension, lateral flexion, & rotation.
Rotation moderate from C2 down.
Fig 9.6a

8. Articulation of Vertebral Arches: Thoracic
Facets face backward, slightly upward & laterally.
Permit rotation & lateral bending.
Fig 9.6b

9. Articulation of Vertebral Arches: Lumbar
Facets face inward & slightly backward.
Locked against rotation.
Permits flexion & hyperextension.
Fig 9.6c

10. Articulation of Vertebral Arches: Ligaments
Fig 9.7

11. Atlanto-Occipital Articulation
Fig 9.8
Condyles of occipital bone articulate with articular fossa of the atlas.
The two joints act like a hinge joint.
Permit flexion & extension.

12. Atlantoaxial Articulation
Perfect example of a pivot joint.
Sole function is rotation.
Odontoid process projects upward from axis, held in place by transverse ligament.
Fig 9.9

13. MOVEMENTS OF THE SPINE AS A WHOLE
Flexion Hyperextension
Fig 9.11a & b

14. MOVEMENTS OF THE SPINE AS A WHOLE
Lateral flexion Rotation
Fig 9.11c & d

15. Regional Classification of Spinal Movements
Atlanto-occipital joint
Flexion & extension, hyperextension.
Slight lateral flexion.
Atlantoaxial joint
Rotation
Remaining cervical joints
Lateral flexion.

16. Regional Classification of Spinal Movements
Thoracic region
Moderate flexion
Slight hyperextension
Moderate lateral flexion
Rotation
Lumbar
Flexion & extension, hyperextension
Lateral flexion
Slight rotation

17. Factors Influencing Stability & Mobility of the Spine
Pressure & Tension Stresses:
Discs push vertebrae apart & ligaments pull
them together.
Anteroposterior Curves:
Influence the nature & degrees of motion in different regions.
Relative Thickness & Shape of Discs:
Greater freedom of motion where discs are thick.
Thickness & Strength of Ligaments:
Regional differences influence motions permitted.

18. Factors Influencing Stability & Mobility of the Spine
Direction & Obliquity of Articular Facets:
Regional characteristics determine motion permitted.
Size & Obliquity of Spinous Processes:
Thoracic overlap & limit hyperextension; lumbar are horizontal & do not restrict motion.
Articulations of Ribs with Vertebrae:
Limit lateral flexion in thoracic region.

19. MUSCLES OPERATING SPINAL COLUMN: Anterior Aspect
Cervical Region
Prevertebral muscles (longus capitis & coli, rectus capitis anterior & lateralis).
Hyoid muscles (suprahyoids & infrahyoids).
Thoracic
Abdominal muscles:
Obliquus externus & internus abdominis
Rectus abdominis
Transverse abdominis

20. MUSCLES OPERATING SPINAL COLUMN: Posterior Aspect
Cervical Region Only
Splenius capitis & cervicis.
Suboccipitals
Cervical, Thoracic & Lumbar Region
Erector spinae.
Deep posterior spinal muscles.
Semispinalis thoracis, cervicis, and capitis

21. MUSCLES OPERATING SPINAL COLUMN: Lateral Aspect
Cervical Region
Scalenus anterior, posterior, & medius.
Sternocleidomastoid.
Levator scapulae.
Lumbar Region
Quadratus lumborum.
Psoas major.

22. MUSCLES OPERATING SPINAL COLUMN
Prevertebral Muscles
Function:
Singly: laterally flex & rotate to opposite side.
Together: flex head & neck.
Fig 9.13

23. MUSCLES OPERATING SPINAL COLUMN
Hyoid Muscles
Function:
Flex head & neck, aid swallowing.
Fig 9.14

24. MUSCLES OPERATING SPINAL COLUMN
Obliquus Externus Abdominis
Function:
Singly: laterally flex & rotate spine to opposite side.
Together: flex thoracic & lumbar spine.
Fig 9.15

25. MUSCLES OPERATING SPINAL COLUMN
Obliquus Internus Abdominis
Function:
Singly: laterally flex & rotate spine to the same side.
Together: flex thoracic & lumbar spine.
Fig 9.16
Thoraco-
lumbar
fascia
Obliquus
Internus
abdominis
Rectus sheath
(anterior leaf)
Inguinal
ligament

26. MUSCLES OPERATING SPINAL COLUMN
Fig 9.17
Rectus Abdominis
Function:
Singly: laterally flex spine.
Together: flex thoracic & lumbar spine.

27. MUSCLES OPERATING SPINAL COLUMN
Transversus Abdominis
Function:
Stabilize trunk.
Fig 9.18

28. MUSCLES OPERATING SPINAL COLUMN
Splenius Capitis & Cervicis
Function:
Singly: laterally flex head & neck, and rotate them to the same side.
Together: extend & hyperextend head & neck.
Fig 9.19

29. MUSCLES OPERATING SPINAL COLUMN
Levator Scapulae
Function:
Singly: laterally flex neck.
Together: stabilize neck.
Fig 9.19

30. MUSCLES OPERATING SPINAL COLUMN
Suboccipital Group
Function:
Singly: laterally flex head, or rotates it to the same side.
Together: extend & hyperextend head.
Fig 9.20

31. MUSCLES OPERATING SPINAL COLUMN
Fig 9.21
Erector Spinae
Function:
Bilateral: extends head & spine.
Unilateral: rotates spine to same side.

32. MUSCLES OPERATING SPINAL COLUMN
Fig 9.22
Deep Posterior Spinal Muscles
Function:
Symmetrical: extends & hyperextends spine.
Asymmetrical: rotates spine to opposite side and assists in lateral flexion.

33. MUSCLES OPERATING SPINAL COLUMN
Fig 9.23
Semispinalis Thoracis, Cervicis, & Capitis
Function:
Singly: lateral flexion & rotates spine to opposite side.
Together: extend & hyperextend thoracic & cervical spine.

34. MUSCLES OPERATING SPINAL COLUMN
Scalenus Anterior, Posterior, & Medius
Function:
Singly: laterally flex neck.
Together: flex cervical spine.
Elevate upper ribs in forced inspiration.
Fig 9.24

35. MUSCLES OPERATING SPINAL COLUMN
Sternocleidomastoid
Function:
Together: flex neck & head.
Singly: laterally flex head & neck, and rotate to opposite side.
Fig 9.25

36. MUSCLES OPERATING SPINAL COLUMN
Quadratus Lumborum
Function:
Singly: laterally flex lumbar spine.
Together: stabilize pelvis & lumbar spine.
Fig 9.26

37. MUSCLES OPERATING SPINAL COLUMN
Fig 7.14
Psoas
Function:
Singly: laterally flex lumbar spine.
Together: stabilize spine.

38. MUSCULAR ANALYSIS OF FUNDAMENTAL MOVEMENTS OF HEAD & SPINE
Cervical Spine & Atlanto-Occipital Joint:
Flexion:
Sternocleidomastoid, scalenes, prevertebral muscles.
Extension & Hyperextension:
Splenius capitis & cervicis, erector spinae capitis & cervicis, semispinalis, deep posterior spinal muscles, suboccipitalis.
Lateral flexion:
Splenius capitis & cervicis, erector spinae, semispinalis, scalenes, sternocleidomastoid.
Rotation:
Sternocleidomastoid, deep posterior spinal muscles, splenius, erector spinae, occipitalis.

39. MUSCULAR ANALYSIS OF FUNDAMENTAL MOVMENTS OF HEAD & SPINE
Thoracic & Lumbar Spine
Flexion:
Abdominals.
Extension & Hyperextension:
Erector spinae, semispinalis thoracis, deep posterior spinal muscles.
Lateral flexion:
Erector spinae, oblique abdominals, quadratus lumborum.
Rotation to Left:
Left internal oblique & erector spinae, right external oblique, semispinalis thoracis, other deep posterior spinal muscles.