The cervical region of the spine provides both stability and mobility. It has the largest range of motion of any spinal region and allows for flexion, extension, lateral flexion, and rotation. Motions at each vertebral level are coupled and dictated by bone shape, ligaments, joints, and other connective tissues. The cervical region transmits weight and stresses from the head through a combination of vertebral bodies, disks, and facet joints. Ligaments and muscles also provide stability and enable motion through their actions.

1. FUNCTION OF
CERVICAL REGION
By : Dr. Vicky Kasundra
1st year MPT (neurological science)

2. PECULIARITIES
• Cervical spine provide both stability and mobility.
• Mobility : most flexible region of the spine.
• Stability : stability privided by atlantooccipital and
atlantoaxial joints. It is essential for support of the head and
protection of the spinal cord and vertebral arteries.
• The design of the atlas is such that it provides more free
space for the spinal cord than does any other vertebra.
• The extra space helps to ensure that the spinal cord is not
impinged during motion that occurs here.

3. KINEMATICS
• The cervical spine is designed for a relatively large amount
of mobility.
• Normally, the neck moves 600 times every hour whether we
are awake or asleep.
• Motion available at cervical spine:
• Flexion
• Extension
• Lateral flexion
• Rotation.

4. • These motions are accompanied by translations that increase
in magnitude from C2 to C7.
• The predominant translation occurs in the sagittal plane
during flexion and extension.
• Excessive anteroposterior translation is associated with
damage to the spinal cord.

5. ANLANTO-OCCIPITAL JOINT
Flexion – extension
• Permits flexion – extension as nodding movement
• Deep walls of the atlantal sockets prevent translations, but
the concave shape does allow rotation to occur.
• In flexion, the occipital condyles roll forward and slide
backward. In extension, the occipital condyles roll backward
and slide forward.
• The combined ROM for flexion-extension ranges from 10 to
30.

9. Rotation and lateral flexion
• There are a few degrees of rotation and lateral flexion is
also available at this segment.
• The total ROM available in both axial rotation and lateral
flexion is extremely limited by tension in the joint capsules.
• During rotation and side flexion occipital condyles rise up
the walls of the atlantal sockets on the contralateral side.

12. ATLANTO-AXIAL JOINT
• Motions available at this joint is rotation, lateral flexion,
flexion, and extension.
Rotation
• Approximately 55% to 58% of the total rotation of the
cervical region occurs at the atlantoaxial joints.
• The atlas pivots about 45 to either side, or a total of about
90.
• The alar ligaments limit rotation at the atlantoaxial joints.
• The remaining 40% of total rotation available to the cervical
spine is distributed evenly in the lower joints.

13. Superior view of rotation at the atlantoaxial joints: The
occiput and atlas pivot as one unit around the dens of axis.

14. Lateral flexion & rotation
• Lateral flexion and rotation are coupled motions.
• In the upper cervical segments, lateral flexion is coupled
with contralateral rotation and rotation is coupled with
contralateral lateral flexion.

16. LOWER CERVICAL SEGMENTS
• The shape of the zygapophyseal joints and the interbody
joints dictates the motion at the lower cervical segments.
• Pure anterior translation does not occur, because it would
cause the zygapophyseal joints to about one another.

17. Flexion – Extension
• During flexion anterior tilt of the cranial vertebral body
coupled with anterior translation occur.
• During extension posterior tilt of the cranial vertebral body,
coupled with posterior translation occur.

19. Lateral flexion and rotation
• Lateral flexion and rotation are also coupled motions,
because movement of either alone would cause the
zygapophyseal joints to about one another and prevent
motion.
• Lateral flexion is coupled with ipsilateral rotation, and
rotation is coupled with ipsilateral lateral flexion.
• These motions are also a combination of vertebral tilt to the
ipsilateral side and translations at the zygapophyseal joints.

20. FACTOR DETERMINES
KINEMATICS
Bone Shape
• The range for flexion and extension increases from the
C2/C3 segment to the C5/C6 segment, and decreases again at
the C6/C7 segment.
Ligament, Joint Capsule and joints
• The zygapophyseal joint capsules and the ligaments, in
addition to the shape of the joints, dictate motions at all of
the cervical segments.

21. The zygapophyseal joint capsules are generally lax in the cervical region,
which contributes to the large amount of motion available here.
Body height/Disk Ratio
• The height is large in comparison with the anteroposterior and
transverse diameters of the cervical disks. Therefore, a large amount of
motion occur at cervical spine.
• The disk at C5/C6 is subject to a greater amount of stress than other
disks because C5/C6 has the greatest ROM of flexion-extension and is
the area where the mechanical strain is greatest.

22. Age and Gender
• Female have higher ROM than Male.
• Younger have higher degree of ROM than elder.

23. KINETICS
• Cervical region is subjected to axial compression, tension,
bending, torsion, and shear stresses as in the remainder of the
spinal column, there are some regional differences.
• The cervical region differs from the thoracic and lumbar
regions in that the cervical region bears less weight and is
generally more mobile.

24. Load transformation
No disks are present at either the atlanto-occipital or atlantoaxial
articulations
the weight of the head transferred directly through the atlanto-occipital
joint to the articular facets of the axis.
These forces are then transferred through the pedicles and laminae of the
axis to the inferior surface of the body and to the two inferior
zygapophyseal articular processes.
Subsequently, the forces are transferred to adjacent inferior disk.

25. • The laminae of the axis are large, which reflects the
adaptation in structure that is necessary to transmit these
compressive loads
• The trabeculae show that the laminae of both the axis and C7
are heavily loaded, whereas the intervening ones are not.
Loads diffuse into the lamina as they are transferred from
superior to inferior articular facets.
• The loads imposed on the cervical region vary with the
position of the head and body and are minimal in a well-
supported reclining body posture.

26. • In the cervical region from C3 to C7 compressive forces are
transmitted by three parallel columns:
• A single anterocentral column formed by the vertebral bodies
and disks.
• Two rodlike posterolateral columns composed of the left and
right zygapophyseal joints.
• The compressive forces are transmitted mainly by the bodies
and disks, with a little over one third transmitted by the two
posterolateral columns.

27. ligament Kinetics
• Ligament forces responsible for stabilization.
1. Transverse ligament of atlas
Prevents posterior translation of dens and anterior translation
of atlas.

28. 2. Alar ligament
Prevent excessive rotation at the atlanto axial joint.
3. Apical ligament
Prevent flexion at atlanto-axial joint.

29. 4. tectorial membrane/posterior longitudinal ligament
prevent excessive flexion.

30. 5. Anterior longitudinal ligament
Prevent excessive extension
6. Ligamenum flavum
Prevents excessive flexion & lateral flexion.
7. Interspinous ligament
Prevents excessive flexion.

31. 8. Intertransverse ligament
prevent excessive lateral flexion.

32. 9. Ligamentum nuche ( Supraspinous ligament )
Prevents excessive flexion.

33. 10. Capsular ligament
Prevent excessive sliding that occur in apophyseal joint.

34. Muscle kinetics
Flexors
• Sternocleido mastoid (SCM)
• Rectus capitis anterior
• Scalenus Anterior
• Longus colli
• Longus capitis

35. Extensors
• Upper trapezius
• Rectus capitis posterior
• Extensor spinae ( Iliocostalis cervicis, Longissimus cervicis,
Longissimus capitis, Spinalis cervicis, Spinallis capitis &
cervicis )
• Semispanalis & cervicis

36. Lateral flexors
• Erector spinae
• Rectus capitis lateralis
• Scalene
• Sacrospinous
• Splenius capitis & cervicis
• SCM

37. Rotators
• Multifidus
• Semispinalis capitis & cervicis
• Erector spinae