The document summarizes the structure and biomechanics of the cervical spine. It describes the seven cervical vertebrae and their typical and atypical features. It discusses the distinctive structures of the atlas and axis vertebrae. It also outlines the articulations between vertebrae including the atlanto-occipital and atlantoaxial joints. Additionally, it summarizes the ligaments of the craniovertebral region and the motions and couplings between vertebrae in the cervical spine.

1. CERVICAL BIOMECHANICS
DR. NITHIN NAIR (PT)
ASST. PROFESSOR
DEPARTMENT OF COMMUNITY PHYSIOTHERAPY
MGM COLLEGE OF PHYSIOTHERAPY

2. STRUCTURE OF THE CERVICAL REGION
C1
C2
C4
C7
C6
C5
C3
 Seven vertebrae in total
 Morphologically & Functionally – divided into 2 distinct
regions.
 Upper Cervical Spine – includes occipital condyles &
first two cervical vertebrae (C1 & C2)
 Lower Cervical Spine – includes the vertebrae C3 to C7
 Typical Cervical Vertebrae – C3 to C6
 Atypical Cervical Vertebrae – Atlas, Axis, and C7
 Presence of transverse foramen – passage for vertebral
artery.

3. CRANIOVERTEBRAL REGION: ATLAS
Distinctive Features:
 No vertebral body or spinous process
 Shaped like a ring
 Presence of lateral masses – formed by zygapophyseal facets
 4 articulating facets – 2 superior zygapophyseal facets (kidney
shaped, concave) & 2 inferior zygapophyseal facets (convex,
directed inferiorly)
 Transverse process with transverse foramen
 Facet on the internal surface of the anterior arch for
articulation with the dense
Functions:
 Cradle the occiput
 Transmit forces from the occiput to the cervical vertebrae

4. CRANIOVERTEBRAL REGION: AXIS
Distinctive Features:
 Body: Anterior portion extends inferiorly, superior surface of
the body has a vertical projection (Dens)
 Dens: Anterior facet for articulation with anterior arch of
atlas & Posterior groove for articulation with the transverse
ligament.
 Arch: Inferior (face anteriorly) & Superior zygapophyseal
facets (face upward & laterally)
 Spinous process: Long and elongated with a bifid.
Functions:
 Transmit the combined load of the head and the atlas to the
remainder of the cervical spine.
 Provide motion into axial rotation of head and the atlas.

5. TEST YOURSELF

6. TEST YOURSELF

7. TEST YOURSELF

8. ARTICULATIONS
 Atlanto-Occipital Joints – 2 concave superior
zygapophyseal facets of the atlas articulating with the two
convex occipital condyles of the skull.
 True synovial joints with intra – articular fibroadipose
meniscoids and lie nearly in the horizontal plane.

9. ARTICULATIONS
 Atlantoaxial Joints: 3 synovial joints (1 median and 2
lateral atlantoaxial joints)
Median Atlantoaxial Joint:
 Between Dens & Atlas.
 It’s a synovial trochoid (pivot) joint.
Lateral Atlantoaxial Joints:
 Between the superior zygapophyseal facets of the axis
and the inferior zygapophyseal facets of the atlas.
 It’s a plain synovial joints – however, the articular
cartilages of both the atlantal & axial facets are convex
(thus – biconvex and filled with meniscoids)

10. CRANIOVERTEBRAL LIGAMENTS
Anterior Longitudinal
Ligament
Limits Extension
Posterior
Longitudinal
Ligament
Limits Forward Flexion
Tectorial Ligament Limits Forward Flexion
Ligamentum Flavum Limits Forward Flexion
Ligamentum Nuchae Limits Forward Flexion
Alar Ligament Limit rotation of the
(same side)
Lateral flexion (opposite
side)

11. THE LOWER CERVICAL REGION: BODY
Lower Cervical Spine – Includes the vertebrae C3 to C7
C3 – C7

12. THE LOWER CERVICAL REGION: BODY
 Small, transverse diameter > anterior posterior diameter.
 Uncinate process – present at the postero-lateral margins of the
upper surface (concavity in frontal plane)
 Inferior projection of the anterior body (concavity in sagittal
plane)

13. THE LOWER CERVICAL REGION: ARCHES
 Pedicles – Projects posterolaterally
 Laminae – Projects posteromedially
 Zygapophyseal articular process – Superior facets are flat, oval
and face superiorly & posteriorly; inferior facets face inferiorly
and anteriorly.
 Transverse process – Presence of transverse foramen, Presence
of groove for spinal nerves.
 Spinous process – Short, extend horizontally, bifid tip. C2 to C3
(Length decreases slightly), C3 to C5 (Length remains constant),
C7 (Length increases)
 Vertebral Foramen – Large, Triangular

14. TEST YOURSELF

15. INTERVERTEBRAL DISK
 Annulus Fibrosus – Crescent shape
 Cervical discs – Thick anteriorly and taper laterally
 Fissures in the disc develops to become cleft by 9 years of age –
becomes joint cavity (Uncovertebral Cleft or Joints of Luschka)

16. INTERBODY JOINTS OF THE LOWER CERVICAL REGION
 Saddle joints
 In sagittal plane, inferior surface of cranial vertebra (concave) and
superior surface of caudal vertebra (convex)
 In frontal plane, inferior surface of cranial vertebra (convex) and
superior surface of caudal vertebra (concave)
 Predominant motions - Tilting

17. ZYGAPOPHYSEAL JOINTS
 True synovial joints
 Lie midway between frontal and horizontal plane
 Contains fibroadipose meniscoids
 Joint capsules are lax – allows larger ROM
 Restrict motion at the end of available range

18. KINEMATICS: CERVICAL SPINE
Introduction:
 Motion Permitted: Flexion, Extension, Lateral Flexion, Rotations.
 It is accompanied by translation – Increases from C2 to C7
 Predominant translation – Flexion & Extension (sagittal plane)

19. KINEMATICS: ATLANTOOCCIPITAL JT.
Atlanto-occipital Joint
 Motion Permitted: Nodding (Flexion / Extension) + Small
amount of Lat. Flexion & Rotation
 Combined ROM - 15° (Flexion / Extension) with approx. 3° lat.
flexion and axial rotation
Flexion Occipital condyles slide backward and role
role forward.
Extension Occipital condyles slide forward and role
role backward.
Lateral Flexion &
& Axial Rotation
Rotation
Extremely limited by tension in the joint
joint capsules

20. KINEMATICS: ATLANTOAXIAL JOINT
Atlantoaxial Joint:
 Motion Permitted: Rotations, lateral flexion, flexion, and
extension.
 50% approx. – Total rotations of the cervical region occurs at
atlantoaxial joint.
 Remaining 40% - Total rotations of the cervical region evenly
distributed in the lower cervical joints.
 Atlas pivots approx. 45° to either side.

21. KINEMATICS: LOWER CERVICAL
 Available ROM – Flexion / Extension : 126° ± 22°
Flexion Superior Vertebral body: Anterior Tilt
Interbody Joints: Anterior Slide
Inf. Zygapophyseal Facet: Upslide
Extension Superior Vertebral body: Posterior Tilt
Interbody Joints: Posterior Slide
Inf. Zygapophyseal Facet: Downslide

22. KINEMATICS: LOWER CERVICAL
 Available ROM - Lateral Flexion : 87° ± 22°
 Available ROM - Rotation: 144° ± 23°
 Rotation and lateral flexion are coupled motions (Lateral flexion is
coupled with ipsilateral rotation)
 Ipsilateral side (tilt and slide at interbody joints)
 Contralateral side (upslide at zyapophyseal joint)
Right
Lateral
Flexion
Interbody Joint: Tilt & Slide to the right
Left Inf. Zygapophyseal Facet: Upslide
Right Inf. Zygapophyseal Facet: Downslide
Sliding of the facets produces slight rotation of the
of the vertebral bodies to the right
Right side
side
Rotation
Right Inf. Zygapophyseal Facet: Slides posteriorly +
posteriorly + Downslide
Left Inf. Zygapophyseal Facet: Slides anteriorly + Upslide

23. PROTRACTION RETRACTION
KINEMATICS

24. TEST YOURSELF
KINEMATICS: ATLANTOOCCIPITAL JT.
KINEMATICS: ATLANTOAXIAL JOINT
KINEMATICS: LOWER CERVICAL

25. KINETICS: MUSCLE GROUPS
4 functional groups – Superficial Posterior, Deep
Posterior, Superficial Anterior, Deep Anterior.
Superficial
Posterior
Trapezius, Levator Scapulae, Splenius
Capitis, Splenius Cervicis
Deep Posterior Multifidi, Suboccipital
Superficial
Anterior
Sternocleidomastoid, Scalenus
Deep Anterior Longus Colli & Longus Capitis

26. KINETICS
 Cervical region bears less weight and are more mobile
 Cervical spine is lordotic – anterior shear force
 No discs present at atlantooccipital and atlantoaxial articulations – compressive load
transferred directly.
 Laminae of axis and C7 are large to withstand compressive load
 In cervical region from C3 TO C7 – compressive forces are transmitted by 3 columns –
central (major), 2 posterolateral column (one-third)

27. SUMMARY

28. REFERENCE
 JOINT STRUCTURE AND FUNCTION – CYNTHIA NORKIN (5TH & 6TH ED.)
 BIOMECHANICS OF JOINT – SHYAM D. GANVIR (1ST ED.)

29. THANK
YOU!!!