The 16 Major Aberrations of the Cervical Curvature

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INTRODUCTION

For all of our practicing careers as chiropractors (21 yrs for DWM & 6 years for DEH), we have endeavored to improve our patient’s lateral spinal curvatures as a primary outcome of care. Most of our attention, time and studies have involved the cervical spine. This is because the most notable structural and postural aberrations of the lateral spine will usually occur in the cervical region.It is much more common to see a reversed curvature in the cervical spine than the thoracic spine or lumbar spine due to design features that increase stability against Euler and Snap through buckling in the thoraco-lumbar regions.1

First efforts at cervical curve correction, in the early 1980’s, were with various forms of supine cervical extension traction, usually with a foam v-block under the neck.2 CBP® practitioners achieved about a 30-50 percent effective correction ratio with these methods. In at least 50 percent of the cases, the clinicians had to show the patient that, despite all efforts, their curvature did not improve or, in rare cases, slightly worsened.

Looking for improved results, CBP® clinicians started trying different forms of two-way extension traction or compression extension traction as they became available. For a thorough history and time frames, the interested reader is referred Harrison, Harrison, and Haas.2 Using these new methods, CBP® clinicians made better and more consistent changes, but were still only achieving a 50-75 percent (approximately) correction ratio in their patients’ lateral cervical curvatures; especially with kyphotic cervical configurations.3

Later, between the years 1997-20024-6 one of us (DEH), introduced the idea of the Red line/Black line to help determine which type of traction was best for the patient. Although the Red-line-Black-line was used on the lateral cervical and lumbar radiographs in the CBP® Report of Findings as early as 1988 by Sang Harrison, DC, no one had used this analysis to determine the appropriate traction type prior to 1997. With this method, and a special plastic x-ray template (available from CBP®), a red 63-degree arc line is drawn onto the patient’s lateral cervical radiograph. This line represents the ideal position for the posterior vertebral bodies of C1-C7.7 A black line is then drawn on the actual posterior bodies of C2-C7. This simple idea allowed us to look at, and show the patient, the altered form and global position of their cervical curvature in direct comparison to its ideal form and global position.

Looking at cervical curve loss from the perspective of altered form and global position and not just as degrees of lost curvature has allowed us to achieve a quantum leap in our understanding of lateral cervical curve correction. By carefully matching the type of cervical traction to the aberrant form of curve loss, it has become easy to envision that the cervical segments will most effectively be remodeled back to their ideal global posture (the red 63-degree arc line) by a specific traction force. We believe that CBP® doctors are now able to drastically increase their effective correction ratio.

In his video,5 Dr. Deed listed 11 categories of cervical curves and in their 2002 text, he had listed eight categories.6 These categories were based on the type of traction that was illustrated and not on the particular number of cervical geometries. Thus, different geometries of cervical curve types were placed in the same traction category but the angle of applied load in certain traction units were varied (See Chapter 6).6 Currently, CBP® has published three clinical control trials on three types of cervical traction.3,8,9 Clinical Control Trials are dollar and time consuming and we will be years in publishing studies on all types of traction used. Many CBP® practitioners have developed their own equipment that fit mechanical methods to posture and spine correction. It takes some hard work and insight. We feel fortunate to have had some inspirations to develop equipment to aid CBP® clinicians in the management of spinal and postural displacements. In particular, Dr. Don Meyer has developed his own line of equipment that aids in making spinal corrections.

With the idea of lateral cervical geometric displacements (form) instead of numerical lordosis, one of us (DWM) recently studied the possible altered forms of cervical curve loss in comparison to the ideal 63-degree arc line and in the current manuscript proposes that there are 16 major aberrations of the cervical lateral curvature.

These 16 cervical geometric forms will be listed and ideas on correcting these will be presented. Some of these ideas are a different way to correct previously published types by Dr. Deed Harrison,6 and some are uniquely correlated to the ideal form of corrective cervical extension traction and posture corrective exercise. Here we will also list the suggested best setting for the use of the Cervical Remodeling Collar™ (developed by DWM) in regard to each of the major aberrant curvatures. Dr. Don Meyer has recently adapted the CRCollar to be effective at correcting the majority of types of cervical curve loss and forward (or retro) head posture. The reader should keep in mind that proof for this needs to be presented in the form of clinical trials, which are currently being undertaken. Here are the 16 Figures to illustrate the 16 basic types (referred to as Forms).

 

MAJOR ABERRATIONS AND THEIR IDEAL TRACTION AND EXERCISE

Form 1A: All cervical segments are forward of the arc line. Upper cervical spine has increased curve/lower cervical spine has decreased curve. Traction: Supine extension traction, T4 at table edge. CRC: P2/P3, full head retraction

Exercise: Mirror-image® head retractions and/or head-weighting

Form 1B: All cervical segments are forward of the arc line. Upper and lower cervical spine has decreased curve. Traction: Supine extension traction, T4 at table edge. CRC: P2/P3, full head extension with negative Z compression pad, if needed on flexible patients.

Exercise: Mirror-image® head retractions with extension and/or head-weighting.

Form 2A: C6-C1 forward of the arc line/C7 on the arc line. Upper cervical spine has increased curve/lower cervical spine has decreased curve. Traction: Supine extension traction, T4 at table edge. CRC: P2/P3, full head retraction. Exercise: Mirror-image® head retractions and/or head-weighting.

Form 2B: C6-C1 forward of the arc line/C7 on the arc line. Upper and lower cervical spine has decreased curve. Traction: Compression extension traction. CRC: P2/P3, full head extension with negative Z compression pad, if needed on flexible patients. Exercise: Mirror-image® head retractions with extension and/or head-weighting.

Form 3A: C5-C1 forward of the arc line/C7-C6 on the arc line. Upper cervical spine has increased curve/lower cervical spine has decreased curve. Traction: Two-way traction with increased posterior pull. CRC: P1/P2, full head retraction. Exercise: Mirror-image® head retractions and/or head-weighting.

Form 3B: C5-C1 forward of the arc line/C7-C6 on the arc line. Upper and lower cervical spine has decreased curve. Traction: Compression extension traction. CRC: P1/P2, full head extension with negative Z compression pad, if needed on flexible patients. Exercise: Mirror-image® head retractions with extension and/or headweighting.

Form 4A: C4-C1 forward of the arc line/C7-C5 on the arc line. Upper cervical spine has increased curve/lower cervical spine has decreased curve. Traction: Two-way traction with increased posterior pull. CRC: P1, full head retraction. Exercise: Mirror-image® head retractions and/or head-weighting.

Form 4B: C4-C1 forward of the arc line/C7-C5 on the arc line. Upper cervical spine has decreased curve/lower cervical spine is normal. Traction: Compression extension traction. CRC: P1, full head extension with negative Z compression pad, if needed on flexible patients. Exercise: Mirror-image® head retractions with extension and/or headweighting.

Form 5: C3-C1 forward of the arc line/C7-C4 on the arc line. Upper cervical spine has decreased curve/lower cervical spine is normal. Traction: Seated compression extension traction. CRC: A1/P1, full head extension with negative Z compression pad, if needed on flexible patients. Exercise: Mirror-image® head extensions.

Form 6A: C7-C6 behind the arc line/C5-C1 forward of the arc line. Upper cervical spine has increased curve/lower cervical spine has decreased curve. Traction: Two-way traction with increased posterior pull. CRC: P1, full head retraction Exercise: Mirror-image® head retractions and/or head-weighting.

Form 6B: C7-C6 behind the arc line/C5-C1 forward of the arc line. Upper and lower cervical spine has decreased curve. Traction: Compression extension traction. CRC: P1, full head extension with negative Z compression pad, if needed on flexible patients. Exercise: Mirror-image® head retractions with extension and/or headweighting.

Form 7A: C7-C5 behind the arc line/C4-C1 forward of the arc line. Upper cervical spine has increased curve/lower cervical spine has decreased curve. Traction: Two-way traction with increased posterior pull. CRC: P1, full head retraction. Exercise: Mirror-image® head extensions.

Form 7B: C7-C5 behind the arc line/C4-C1 forward of the arc line. Upper and lower cervical spine has decreased curve. Traction: Compression extension traction. CRC: A1/P1, full head extension with negative Z compression pad, if needed on flexible patients. Exercise: Mirror-image® head extensions.

Form 8: C7-C4 behind the arc line/C3-C1 forward of the arc line. Upper and lower cervical spine has decreased curve. Traction: Two-way traction or two-way compression extension traction. CRC: A1-A3 with full head extension. Exercise: Mirror-image® head extensions.

Form 9: C7-C3 behind the arc line/C2-C1 forward of the arc line. Upper and lower cervical spine has decreased curve. Traction: Two-way traction or two-way compression extension traction. CRC: A1-A3 with full head extension. Exercise: Mirror-image® head extensions.

Form 10: All cervical segments are behind the arc line.Upper and lower cervical spine has decreased curve. Traction: Two-way traction or two-way compression extension traction. CRC: A1-A3 with full head extension. Exercise: Mirror-image® head protrusions with extension.

 

CONCLUSION

We used the term “cervical form” to distinguish between the types that (DEH) categorized as some of these “forms” will be included in one of the eight types listed in the CBP® Cervical Rehabilitation book.6 In closing, we would like to give you one last example of looking at form rather than just numerical values of cervical curvature. Many doctors want to know at what number of millimeters of forward head posture should one look for the adverse spinal coupling forces of upper cervical extension and lower cervical flexion to occur?Now some doctors say to look for this to occur at 40 millimeters or more, while others say it needs to be 50 millimeters or more. In the CBP® Cervical Rehab Book, the numerical value of 50mm of +TzH was utilized as an approximate “guideline” for when the lower cervical spine becomes kyphotic. The literature simply states that as the head translates forward and the lower cervical spine moves into flexion, its curvature should gradually straighten and eventually become significantly flexed (it does not state that it will become kyphotic; this is inferred with larger magnitudes of +TzH) while at the same time, the upper cervical spine should gradually increase its lordosis.10,11

With this definition in mind and our new concept of form and global position, it is easy to see that the best answer to our question is that, in a normal spine, as the lower cervical segments (C5-C7) progressively move forward of the 63-degree arc line (Form 1,2 and 3 of the16 forms) into flexion, expect them to slowly straighten or reverse and expect to see an increased lordosis of the upper cervical spine as well. In some people, C5 may start moving forward of the 63-degree arc line at 30 millimeters, while others it may be 40 or even 50 millimeters. It all depends on their unique, individual lateral cervical form and global position. This is exactly what was meant by Harrison, Harrison, and Haas,6 (Ch.2, pg. 24) when they stated, “it is important to note that the majority of studies detailing spinal coupling patterns have utilized maximum or near maximum range of motion. Seldom do patients come in with maximum ROM postural displacements, indicating the need to infer what lesser magnitudes of postural displacements will look like.”

 

REFERENCE

1. Harrison DE, Harrison DD, et al. Three-Dimensional Spinal Coupling Mechanics. Part II: Implications for Chiropractic Theories and Practice. J Manipulative Physiol Ther 1998; 21(3): 177-86.
2. Harrison DE, Harrison DD, Haas JW. CBP® Structural Rehabilitation of the Cervical Spine. Evanston, WY: Harrison CBP® Seminars, 2002, Chapter 4.
3. Harrison DD, Jackson BL, Troyanovich SJ, Robertson GA, DeGeorge D, Barker WF. The Efficacy of Cervical Extension-Compression Traction Combined with Diversified Manipulation and Drop Table Adjustments in the Rehabilitation of Cervical Lordosis. A Pilot Study. J Manipulative Physiol Ther 1994;17:454-64.
4. Harrison DE. CBP® Cervical Rehab Seminars. Evanston, WY: HarrisonCBP® Seminars, 1998.

5. Harrison DE. CBP® Cervical Rehab Video. Evanston, WY: Harrison CBP® Seminars, 2000.

6. Harrison DE, Harrison DD, Haas JW. CBP® Structural Rehabilitation of the Cervical Spine. Evanston, WY: Harrison CBP® Seminars, 2002.
7. Harrison DD, Janik TJ, Troyanovich SJ, Holland B. Comparisons of lordotic cervical spine curvatures to a theoretical ideal model of the static sagittal cervical spine. Spine 1996; 21: 667-675.
8. Harrison DE, Cailliet R, Harrison DD, Janik TJ, Holland B. New 3-Point Bending Traction Method of Restoring Cervical Lordosis Combined with Cervical Manipulation: Non-randomized Clinical Control Trial. Arch Phys Med Rehab 2002; 83(4):447-453.
9. Harrison DE, Harrison DD, Betz J, Janik TJ, Holland B, Colloca C. Increasing the Cervical Lordosis with CBP® Seated Combined Extension-Compression and Transverse Load Cervical Traction with Cervical Manipulation: Non-randomized Clinical Control Trial. J Manipulative Physiol Ther 2003; 26(3): 139-151.
10. Penning L. Acceleration injury of the cervical spine by hypertranslation of the head. Part I, effect of normal translation of the head on cervical spine motion: a radiological study. Eur Spine J 1992; 1:7-12.
11. Ordway NR, et al. Cervical flexion, extension, protrusion, and retraction. A radiographic segmental analysis. Spine 1999;24:240-247.