CERVICAL SPINE ANIMATIONS

A Research Project in Search of a Forum

Ed Owens
Director of Research
Sherman College of Straight Chiropractic

Multimedia presentations don't really fit in well with the standard research platform presentation. What's more, computer graphics don't fit in at all in scientific publications, yet the work has merit in that it clearly demonstrates vertebral kinematics. As an alternative to the standard research forum, we are offering these animations to the online public at large. Whole animations or individual frames can be used in multimedia presentations composed in application software such as Microsoft's Powerpoint or Lotus Freelance for custom-made patient education presentations. This is copyrighted material, however and cannot be sold by you without prior arrangement with Life University.

All of the animations listed below are available in both Windows Animation format (.AVI) and Quicktime Movie (.MOV) format. The AVI format is native to MS-Windows and can be displayed with the Media Player application. Quicktime viewers for MS-Windows and MacIntosh are available from Apple Corporation. Both Media Player and Quicktime viewers allow you to scale the image on screen, play the animations one frame at a time, and copy individual frames to the clipboard for transfer to other graphics applications.

A note about file sizes: All of the animations were rendered at both 320x240 and 640x480 resolution in 256 colors. The size of the files ranges from about 800Kbytes to 1.2 Megabytes for the 640x480 files, and from 250Kbytes to 500Kbytes for the lower resolution versions. If your Internet connection is via MODEM, choose the smaller files for more reasonable download times.

The representative intersegmental ranges of motion used in these animations is from: White AA, Panjabi MM: The basic kinematics of the human spine. Spine 3:12, 1978. In general the animations were programmed using joint architecture as a guide: movements were designed to maintain uniform joint contact and alignment. More specifics about the production techniques can be found in a second abstract, presented at the 12th Annual Upper Cervical Conference. Some representations of abnormal motion are provided to illustrate the joint reactions to fixation and incorrect axis of rotation. Please note that all of these animations are computer programmed to represent hypothetical spinal motions.

	Cardinal Global Motions	Files
	Model overview: A view of the whole cervical spine model spinning. The mouth opens to permit viewing of the C1-C2 segment from the Anterior.	AVI Big :: Small MOVBig :: Small
	Stereo View of Model: The viewpoint changes in this animation to show the model from the AP, Lateral and Vertex directions. A misalignment pattern has been introduced to mimic the results of x-ray analysis on a patient. You'll need to get out your reb/blue stereo glasses for this one. (The glasses Wendy's was distributing back in May for special TV shows work just great.) This animation along with an abstract were presented at the Research Agenda Conference in June, 1997.	AVI Big :: Small MOVBig :: Small
	Cervical Flexion/Extension: This animation shows flexion/extension of the cervical spine from the lateral view. You can see how the motion is initiated at the head and spreads downward.	AVI Big :: Small MOVBig :: Small
	Flexion with fixation: A second version of this animation shows the effects of fixation at C4-C5. While the fixed vertebra don't separate as they should, the global range of motion is preserved by hypermotion of the segments above and below.	AVI Big :: Small MOVBig :: Small
	Cervical Rotation: Cervical rotation is initiated at the C1-C2 joint, with most of the motion occuring there before the lower segments begin to move. You can see that lateral flexion is coupled with rotation in the lower cervical spine: as the spinous processes deviate from the midline, there is a tipping of the vertebrae so that the head tips as rotation reaches its maximum. In normal cervical rotation, lateral flexion occurs at the Occipito-atlantal joint to compensate for the lateral flexion in the lower cervicals, keeping the plane of vision horizontal.	AVI Big :: Small MOVBig :: Small
	Cervical Lateral flexion: Since lateral flexion and rotation are coupled in the cervical spine, you can see spinous deviation away from the midline as lateral flexion occurs.	AVI Big :: Small MOVBig :: Small
	Cervical Curve Patterns: An animation showing a continuum of cervical curves from hyperlordotic with anterior head carriage, to kyphotic. The inclination of C7 and the relative intersegmental flexions defiining the range of curvature were taken from x-ray analysis of patients' lateral cervical x-ray	AVI Big :: Small MOVBig :: Small

	Occipito-Atlantal Motion	Files
	Flexion/Extension: A side view of flexion and extension at the occiput. The joint works very much like a knuckle in this motion, with the center of rotation located slightly above the joint.	AVI Big :: Small MOVBig :: Small
	Rotation: It was long considered that no rotation occurred at C0-C1, however cadaver studies have demonstrated about 10 degrees of motion there. This animation of an inferior view of the occiput and atlas shows symmetrical rotation of the skull with respect to the atlas.	AVI Big :: Small MOVBig :: Small
	A second animation of C0-C1 rotation showing the effect of fixation at one condyle. The center of rotation is shifted to the side of fixation.	AVI Big :: Small MOVBig :: Small
	Lateral Flexion: Eight degrees of lateral flexion is considered normal between the occiput and atlas. This animation shows the motion with the center of rotation located above the joint, at the intersection of perpendicular bisectors of the atlas joint surfaces.	AVI Big :: Small MOVBig :: Small

	Atlanto-Axial Joint	Files
	C1-C2 Flexion/extension: A side view of atlanto-axial flexion/extension showing the complexity of the motion. The atlas tips and glides on the axis in order to keep the anterior arch in uniform contact with the dens.	AVI Big :: Small MOVBig :: Small
	An x-ray view of Flexion/Extension shows the atlanto-dens interspace during the motion.	AVI Big :: Small MOVBig :: Small
	C1-C2 Rotation: A top view of atlanto-axial rotation showing why the ring of the atlas is so large compared to the diameter of the canal space below.	AVI Big :: Small MOVBig :: Small
	C1-C2 Rotation: A side view of atlanto-axial rotation. Because the joint surfaces are bi-convex, there is a tendency for the atlas to translate up and down as it rotates. The translation might be helpful in keeping the capsular ligaments between C1 and C2 from being over stretched by the great amount of motion there.	AVI Big :: Small MOVBig :: Small
	C1-C2 Rotation: A posterior view of atlanto-axial rotation showing the up and down translation that occurs with rotation. You can see the joint spacing very well when the atlas is in the neutral position, but when rotation ensues, the joint space vanishes in the AP projection.	AVI Big :: Small MOVBig :: Small
	C1-C2 Lateral Flexion: Lateral flexion at C1 and C2 is normally considered to be nonexistant. In the presence of transverse ligament damage or laxity, the dens might be seen to displace from the midline of the Atlas. The Atlas would also tip as it slid along the superior surface of C2.	AVI Big :: Small MOVBig :: Small

	C2-C3 Motion Segment	Files
	C2-C3 Flexion/Extension: A side view of C2-C3 flexion and extension showing how the disc and posterior articulations interact during the motion. The posterior joints are only slightly inclined at C2-C3, causing the center of rotation during flexion to be below the disc. This produces a shearing motion in the disc and ultimately limits the amount of flexion that can occur at that level to about 8 degrees.	AVI Big :: Small MOVBig :: Small
	C2-C3 lateral flexion: Lateral flexion and rotation at C2-C3 are so strongly coupled that there really is no difference between lateral flexion and rotation at that level. This animation shows a posterior view of the motion. Notice how C2 tips as the spinous deviates from the midline.	AVI Big :: Small MOVBig :: Small
	Lateral flexion side view: shows the intervertebral foramen, the joint of Luschka and the posterior joint surface during the motion	AVI Big :: Small MOVBig :: Small

	C6-C7 Motion Segment	Files
	C6-C7 Flexion/extension: A side view showing flexion and extension at C6-C7. The posterior joints are more steeply inclined in the lower cervical spine so that the center of rotation is close to the center of the disc. Note the wide separation of the spinous processes during full flexion.	AVI Big :: Small MOVBig :: Small
	C6-C7 Lateral flexion: A posterior view of C6-C7 during lateral flexion. The motion presented here is asymmetrical: lateral flexion to the right is properly coupled with rotation, as evidenced by slight spinous deviation to the left, while lateral flexion to the left has no rotation associated with it. You can see how the posterior joints stay in uniform contact when coupling is present, but either collide or separate when rotation does not occur with lateral flexion.	AVI Big :: Small MOVBig :: Small
	Lateral flexion, side view: of the same motion shows the gliding of the posterior joint when coupling is present, and the separation of the posterior joint on the right when coupling is not present.	AVI Big :: Small MOVBig :: Small
	C6-C7 Rotation: A posterior view of rotation of C6 and C7. Again, the animation shows the effects of coupled motion. Spinous deviation to the right is associated with lateral flexion to the left. You can see the smooth gliding of the posterior joints. When coupling is not present, as shown by spinous deviation to the left without lateral flexion, the posterior joints on the left are seen to collide.	AVI Big :: Small MOVBig :: Small
	Rotation, side view: Shows the joint collision that would occur on C6-C7 rotation if lateral flexion were not coupled with the primary motion.	AVI Big :: Small MOVBig :: Small

	Grostic "Kink" Subluxation Pattern	Files
	In the Grostic Method, an upper cervical analysis and adjusting technique, the "Kink" subluxation exists when the skull is laterally flexed on the atlas and the atlas is laterally flexed to the same side with respect to the lower cervical spine. This animation shows the movement of the skull and atlas with respect to the lower cervical spine during movement into and out of the Kink.	AVI Big :: Small MOVBig :: Small
	A close up view of the occipito-atlanto-axial joints in lateral flexion to the same side.	AVI Big :: Small MOVBig :: Small
	A superior view, from above the occiput, showing the change in the spinal canal in the presence of a Kink Subluxation.	AVI Big :: Small MOVBig :: Small
	"Kink" Pattern - x-ray view: The "Kink" subluxation shown in transparent AP view, simulating the nasium x-ray. The center of rotation of the skull with respect to the atlas is above the Occipto-atlantal joint at the center of the "condylar circle" formed by the joints.	AVI Big :: Small MOVBig :: Small
	Simulated Adjustment: Animation of one model of upper cervical instrument adjustment. The raising or lowering the headpiece is done during the setup for the adjustment to help control C2 and lower spine rotation.	AVI Big :: Small MOVBig :: Small

	Grostic "Opposite Angles" Subluxation Pattern	Files
	The other major subluxation pattern, the "Opposite Angles" presents with the upper angle and lower angles acute on opposite sides of the atlas. The overall effect is that the skull seems to slide sideways on the lower cervical spine. The lateral flexion of atlas on C2 is countered by a lateral flexion of the skull on the atlas, so that the skull may remain neutral, without any apparent lateral flexion.	AVI Big :: Small MOVBig :: Small
	A close up view of the occipito-atlanto-axial joints in lateral flexion to opposite sides.	AVI Big :: Small MOVBig :: Small
	A superior view, from above the occiput, showing the change in the spinal canal in the presence of an Opposite angles subluxation.	AVI Big :: Small MOVBig :: Small
	Opposite Angles - x-ray view: The "Opposite Angles" pattern in transparent AP view, simulating the nasium x-ray. Notice how the atlas slides and tips along the "axial circle" formed by the superior joint surfaces of C2.	AVI Big :: Small MOVBig :: Small
	Simulated Adjustment: Animation of one model of upper cervical instrument adjustment. The raising or lowering the headpiece is done during the setup for the adjustment to help control C2 and lower spine rotation.	AVI Big :: Small MOVBig :: Small

Feedback to eowens@sherman.edu