OVERVIEW OF BLAIR CERVICAL TECHNIQUE
 
   

Overview of the Blair Cervical Technique

This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to:
   Frankp@chiro.org
 
   

E. A. Addington, M.A., D.C.
Blair Chiropractic Clinic
Lubbock, Texas


Prepared for
Council on Chiropractic Practice
Chandler, Arizona
October 2-3, 1995


History

Dr. William G. Blair began to develop his distinctive method for the analysis and correction of subluxations of the cervical spine soon after graduating from the Palmer School of Chiropractic and establishing his practice in Lubbock, Texas, in Late 1949. Trained in the classical Upper Cervical Specific (HIO) method, Dr. Blair soon became concerned with the potential effects of osseous asymmetry ("malformation," as he termed it) on the accuracy of the traditional spinographic analysis in producing a valid adjustive listing. His observations of skeletal specimens also led him to conclude that the prevailing view of the misalignment of atlas in relation to the occiput was inaccurate: atlas could not move in a truly lateral direction because the slope of the lateral masses and the condyles created an osseous locking mechanism preventing such motion, and atlas could not rotate in relation to occiput in the coronal plane without causing a gapping of the atlanto-occipital articulations due to the complementary shapes of the articular surfaces of the occipital condyles and the lateral masses.

Working in his own practice, Dr. Blair developed methods for imaging misalignments of the cervical vertebrae at the margins of their articulations, as those articulations are formed in each individual patient, thereby eliminating asymmetry as a source of error in spinographic analysis. He developed new concepts of the misalignment pathways of the cervical vertebrae which made it possible to tailor the adjustment precisely to the shape and orientation of the articulation being adjusted, as it presented in each case. Both the spinographic analysis and the delivery of the adjustment itself could therefore be "customized" to accommodate each individual patient s anatomical situation.

Upon the unremitting insistence of a trusted colleague to whom he had shown the work privately, D. Blair began to teach his technique to the field in about 1961. The work was taught as Primary and Advanced courses of three days each, with the Primary course covering primarily spinographic imaging and misalignment concepts and the Advanced course treating adjustive methods. (For a time the two course were taught consecutively as a five-day combined course, but Dr. Blair considered this approach too demanding of the students.) Dr. Blair continued to teach his work actively until 1980. He continued to refine all aspects of the system during his active teaching phase as well as after it. After his retirement from practice in 1982 he continued to develop adjustments for multiple misalignments of atlas which were field tested by Dr. R. Weldon Muncy of Lancaster, California.

Teaching and research of the Blair technique has been continued since Dr. Blair s passing by the William G. Blair Chiropractic Society, Inc., a 501(c)(3) qualified Texas non-profit corporation which credentials instructors, sponsors research, and holds annual educational conferences. The Blair curriculum is currently divided into four courses of two days each. Research projects to date have focused primarily on interobserver reliability studies of measurements and perceptual judgements made on Blair Cervical Series spinographs.

Despite the proliferation of orthogonally-based upper cervical techniques deriving from the work of John F. Grostic and ultimately from B. J. Palmer, the Blair Technique remains the only non-orthogonal precision spinographic and adjustive technique for the cervical spine in the chiropractic profession. Senior practitioners of the technique continue to refine its concepts and methods within the distinctive articular approach to the cervical subluxation, and to share these developments in the course work and educational conferences of the Blair Society.


Objective

The Blair Technique has as its exclusive concern the analysis and correction of subluxations of the cervical vertebrae, and as its only goal the consequent relief of adverse mechanical influences on the neurological structures of the cervical spine. Subluxated articular misalignments are analyzed as they displace the neural rings, thereby occluding the neural canal and compromising cord space. The clinical objective of the technique is therefore to restore maximum patency of the neural canal in the cervical region. Biomechanical or orthopedic standards of alignment are not the objective of the technique because they are vulnerable to violations of symmetry and do not necessarily bear any relation to the relief of nerve interference in a given case.


Analytical Procedures

The presence of nerve interference in the cervical spine is determined by the observation of both a persistent differential paraspinal dermothermographic pattern in the cervical region and a functional leg length deficiency. A dual-probe instrument is used for detecting and recording continuous heat differentials in the cervical paraspinal area, with the instrument glide proceeding superiorly from about T1 spinous process to about the superior nuchal line. At least two, and preferably three, consecutive readings, taken on separate days, are required to determine the patient s individual, characteristic heat pattern indicative of nerve interference. The individuals s pattern is defined by those unilateral heat deflections ("breaks") which are invariably present on each of the pre-adjustive readings. Except in the case of a new injury changing misalignment, the patient is not re-adjusted subsequent to the initial adjustment until the original dermothermographic pattern has returned, in the presence of a functional short leg length deficiency. (Dr. Blair required these findings on two separate occasions not more than seven days apart before re-adjusting the patient, as do some contemporary practitioners.)

The functional leg length deficiency has traditionally been assessed in the prone position without further elaboration. However, many current practitioners add the Thompson-Derifield procedures or modified Prill procedures, or both, and some practitioners use the supine balance test, either instead of the prone testing or in conjunction with it. (See Appendix A for further discussion of the applications of dermothermographic and spinal balance testing.)

A concise summary of the Blair cervical spinographic analysis has been published previously and is included as Appendix B, to which the reader is here referred.


Adjusting Procedures

The Blair Toggle-Torque adjustive thrust, developed from the adjustive methods of B.J. Palmer, is a distinctive toggle mechanism without recoil on the part of the adjustor and incorporating 180-degree torque. It is applied with the patient placed in the side posture on an adjusting table with a drop headpiece. Crucial to proper application of the Blair Toggle-Torque is the mastery of the "pisiform lead," in which the contacting surface of the adjuster s pisiform remains in firm contact with the segmental contact point throughout the adjustive thrust, rather than describing a helical pathway as in some other upper cervical techniques.

One unique feature of Blair Technique is that, for any given articular misalignment to be adjusted, the clinician has a choice of adjustments permitting either an ipsilateral or a contralateral segmental contact. Superior or inferior torque is used, depending upon the misalignment and choice of contact. (In adjusting posterior-inferior atlas listings no torque is used, and the adjustor does recoil his hands from the thrust.)

Listings of any cervical vertebrae may be adjusted using the Blair method, although Dr. Blair did not adjust below C4, and some current practitioners do not adjust below C2 or even C1. Atlas is analyzed and listed as misaligning either obliquely anterior-superior or obliquely posterior-inferior along either or both of the long axes of the atlanto-occipital articulations. Adjustments of atlas require the doctor to orient along up to three angular measurements of C1 or the condyles from the spinographic series, depending upon the misalignment. Ipsilateral or contralateral condylar slope, atlas plane line in the lateral view, convergence of the ipsilateral atlanto-occipital articulation, and posterior condylar convexity measurements may be incorporated in the adjustment, depending upon the listing and choice of segmental contact. Atlas contacts are made on transverse process or posterior arch.

Axis and subjacent cervical segments are analyzed and listed as misaligning either anterior-superior or posterior-inferior at one or both apophyseal articulations. The slope of the relevant articulation is used in the adjustment, and segmental contact points may include the ipsilateral or contralateral lamina or spinous process. In cases where two segments (usually C2 and C3) have misaligned together to the same extent in relation to the subjacent segment, both segments may be contacted simultaneously in the adjustment. Where two adjacent segments have misaligned in opposite directions, opposing contacts (using both hands) may be made on the two segments simultaneously.


Outcome Assessment

Differential paraspinal dermothermography and spinal balance testing are used post-adjustment to verify relief of nerve interference. While most clinicians post-test the patient immediately after the adjustment and a required resting period, some practitioners defer the post-test to the next visit. During the corrective phase of care it is common to test the patient for the return of nerve interference at intervals of twice weekly for at least 6-8 weeks, and Dr. Blair did not hesitate to insist that the patient be tested at this frequency for three to 18 months initially, depending upon the initial severity and complications of the case. Responsible case management past the initial corrective phase of care will encourage the patient to return for testing at about monthly intervals for life, since the subluxation may return at any time with or without identifiable injury and with or without immediate symptomatic manifestation. To instruct the stabilized patient merely to return on a symptomatic basis is to court the loss of progress achieved.

Comparative A-P Open Mouth and flat Lateral Cervical views may be made at an interval of weeks to months after the first adjustment to assess expected changes in the cervical curve, cervical scoliosis, head tilt, lower cervical angulation, or apparent rotation. In difficult cases or where the initial misalignment was large or complex, comparative articular study views may also be made for comparison. Post-adjustive spinographs are not considered a routine part of the system, however, and many practitioners prefer to reserve the patient exposure against possible future injuries.

Probably the most important outcome measure of all is a less formal one: how long does the patient hold the adjustment? Taking into account the patient s age and condition, severity and chronicity of the injury, degenerative changes, activities and lifestyle, the failure of a patient to hold the adjustment and remain free of chiropractic neurological signs for significant continuous periods of time (at least weeks to months in the average patient, after the first several weeks of care) may indicate the need to reevaluate the case, except in anomalous situations. Comparative Blair Cervical Series spinographs are justified in such a case.


Appendix B

Blair Cervical Spinographic Analysis


Presented to the Conference on Research and Education

Monterey, California 06/21-23/1991


E. A. Addington, M.A., D.C.

Blair Chiropractic Clinic

Lubbock, Texas




The technique developed and taught by the late William G. Blair, D.C., Ph.C., F.I.C.A., is an exclusively cervical technique which considers subluxations of C1 through C4. (A number of contemporary practitioners extend the analysis and adjustive procedures through the entire cervical spine.) The presence of cervical nerve interference is established by observation of both persistent differential paraspinal dermothermographic pattern and functional leg length deficiency (traditionally assessed in the prone position). The misalignment component of the subluxation is demonstrated radiographically by means of specially developed spinographic views which are customized to each patient s anatomy.

Dr. Blair s spinographic research and clinical procedures [1, 7] were propounded on his empirical observations [2-7] that clinically significant asymmetry ("malformation") of bilateral structures usually employed in cervical spinographic analysis is the rule rather than the exception. The simplifying assumption underlying Dr. Blair s system is that, regardless of asymmetry, the opposing surfaces of a joint develop in such a way that their margins are identical in conformation. Therefore, properly-imaged and properly-aligned articulations will demonstrate certain observable and classifiable disappositions at their osseous margins. If vertebrae misalign, and in the absence of fracture, that misalignment must take place at articulations. The articulation is therefore the most anatomically accurate place to assess the alignment of a vertebra.

Dr. Blair developed a two-stage system of visual spinographic analysis which permits assessment of vertebral alignment at the articular margins as those articulations are formed in each individual patient and which is therefore insensitive to violations of the assumption of bilateral symmetry. A scout series, traditionally comprised of Base Posterior, A-P open mouth, and five-degree rotated Lateral Cervical views, is used to determine the optimum angles from which to observe the atlanto-occipital and apophyseal articulations. An articular series, which includes Blair Oblique Protractoviews of each atlanto-occipital articulation and a Blair Lateral Cervical Stereoscopic view made at a specific degree of rotation and tube elevation, is used to determine cervical articular alignment. The Blair Protractoclamp, a patented patient positioning device which permits the taking of cervical radiographs at specific degrees of rotation, is necessary to perform both the scout series and articular series, which together comprise the Blair Cervical Series.

The Base Posterior view (which is similar to the diagnostic Submental Vertex view but must be free of appreciable head-tilt and must meet additional positioning criteria) is used to plot and measure convergence angles (representing the longitudinal axes) of the respective atlanto-occipital articulation according to a distinctive method originated by Dr. Blair. The Blair Principle of Atlanto-Occipital Misalignment states that, in the non-fractured and non-dislocated atlas, misalignment with respect to the occipital condyles occurs in an obliquely-anterior or obliquely-posterior direction parallel to one or both of the atlanto-occipital convergence angles. The Base Posterior view is also used to study osseous asymmetry of the foramen magnum, condyles, lateral masses and spinal canal; to assess deviations in the course of the neurological contents of the foramen magnum and cervical spinal canal; to study the formation of the atlas transverse processes and posterior arch for adjustive considerations; and to contribute information for the selection of an ipsilateral or contralateral adjustive contact. The convergence angle is also used in adjusting certain atlas listings.

The A-P Open Mouth view is used to study lateral deviations of the neural rings which may be causing brainstem or cord pressure, asymmetries of occipito-atlanto-axial structures and their resulting developmental or biomechanical compensation patterns, and apparent spinous process rotations. In conjunction with the 5-degree-rotated scout Lateral Cervical view, the A-P Open Mouth view is also used to prescribe the direction and amount of patient rotation (usually from 0 to 5 degrees) and central ray placement superior-to-inferior (usually at the level of the external auditory meatus or of the lower cervicals) for best visualization of the C2-C4 articulations on the Blair Lateral Cervical Stereoscopic view. Some contemporary practitioners omit the scout Lateral Cervical view and take 5-degree rotated Lateral Cervical Stereoscopic views from both the left and the right sides to obtain more complete visualization of the articulations from C2 inferiorward.

Blair Oblique Protractoviews of each atlanto-occipital articulation are made with the patient turned in a positioning chair and secured in Blair Protractoclamps at an angle equal to the convergence angle of the articulation being studied, so that the central ray is directed obliquely anterior-to-posterior along the convergence angles of each of the respective articulations. In this manner the antero-lateral (distal) margins of each of the articulations may be clearly imaged (often by means of stereoscopic views, depending upon the amount of superimposed osseous densities) and trichotomously classified as being either juxtaposed, overlapped (atlas lateral mass margin more antero-lateral than condyle margin), or underlapped (lateral mass margin less antero-lateral than condyle margin). These appositional judgements of each articulation may then be combined to deduce the actual unilateral or ambilateral misalignment pathway(s) of atlas in relation to occiput, and an anatomically accurate misalignment listing and adjustive formula may thus be derived.

The Blair Lateral Cervical Stereoscopic view, or the alternative bilateral rotated Lateral Cervical Stereoscopic views are read using a stereo viewbox or stereo binoculars, permitting differentiation of the left and right apophyseal articulations and three-dimensional visualization of the neural canal. Appositional determinations are made at the anterior margins of the apophyseal articulations, and the superior vertebra is listed as being either juxtaposed, misaligned anterior-superior, or misaligned posterior-inferior at the articular margin on each side. Corresponding anterior or posterior displacements of the posterior aspect of the vertebral body is usually observable on the side of a posterior-joint misalignment. Stereoscopic study of the course of the neural canal on these views is of great importance in determining the segment(s) to be adjusted.

In some cases the posterior articulations between C2 and C3 will be observed to be formed with a semi-sagittal joint plane. In these cases, C2-C3 apposition is usually determinable from the Blair Oblique Protractoviews, on which the margins of these "turned articulations" will ordinarily be satisfactorily visible. In rare cases, special Blair Axis views, taken through the ocular orbit or the open mouth, may be necessary to list C2.

Measurement studies of the convergence angles [8] have demonstrated interobserver reliability (Pearson product moment correlation coefficients) ranging from .84 to .90 among experienced clinicians using the same measurement procedures (p less than .01). Means of convergence angles on the right and the left sides were not found to differ to a statistically significant extent (p greater than .01). Convergence angles of left and right articulations, pooled tegether, showed a mean value of about 24.3 +\- 1.6 degrees, with a range of 6 to 58 degrees and a standard deviation of about 8 degrees, in a sample of 45 cases. A weak correlation between convergence angles within-subject was found (r= .40, p less than .01). A mean difference in convergence angle measurements within-subject of 7.25 +/- 1.5 degrees was observed, with a range of zero to 26.5 degrees and a standard deviation of 5.2 degrees.

Interobserver reliability of appositional measurements at atlanto-occipital articular margins has been reported to range from .65 to .79 (Pearson r; p less than .005) on Blair Oblique Protractoviews [9]. Condylar slope measurements from these views, used in the majority of atlas adjustment formulas, demonstrated interobserver reliability ranging from .81 to .92 (Pearson r; p less than .005), while measurements of posterior condylar convexity, used in some atlas adjustments, ranged from .21 to .84 (Pearson r; p less than .05) in interobserver reliability due to slight differences in measurement methods.

Interobserver reliability of articular determinations subjacent to atlas has not been investigated, although such a project is currently in the early stages of design [10].

Considering only C1 through C4, and taking account of observed or reasonable ranges of convergence, condylar slope and convexity, atlas plane line, and articular slopes of C2-C4, it has been estimated that at least 578,782 distinct adjustments of the upper cervical spine exist within the Blair system. [11] Specificity is critical to proper utilization of the technique.


References:

1.   Blair, Wm. G. Primary Seminar. Advanced Seminar. Five-Day Seminar. Various U.S. locations, ca. 1961-1980.

2.   Blair, Wm. G. A synopsis of the Blair upper cervical spinographic research.
Science Review of Chiropractic (International Review of Chiropractic: Scientific Edition) 1 (1):   1-19 (Nov. 1964).

3.   Blair, Wm. G. For evaluation: for progress. Intl. Rev. Chiro 1968 (Feb:   22 (8):   8-11

4.   Blair, Wm. G. For evaluation: for progress. Intl. Rev. Chiro 1968 (MarR:   22 (9):   8-11

5.   Blair, Wm. G. For evaluation: for progress. Intl. Rev. Chiro 1968 (Jun):   22 (12):   8-11

6.   Blair, Wm. G. For evaluation: for progress. Intl. Rev. Chiro 1968 (Aug):   23 (2):   8-11

7.   Blair, Wm. G. Blair Upper Cervical Spinographic Research; Primary and Adaptive Malformations; Procedures for Solving Malformation Problems; Blair Principle of Occipito-Atlanto Misalignment. Ph.C. Thesis, Palmer College of Chiropractic, 1968.

8.   Addington, E.A., M.G. Howard, M.A. Pruitt, and C.E. Spears.
Objectivity of Blair atlanto-occipital articular convergence angle measurements.
Third Annual Upper Cervical Symposium, Dec. 5-7, 1986, Life Chiropractic College, Marietta, GA. Earlier version presented at the First Annual Convention and Educational Seminar, Wm. G. Blair Chiropractic Society, Inc., October 24-26, 1986, Lubbock, Texas.

9.   Addington, E.A., F. Harkins, R.I. Morrison, R.W. Muncy, and P. Rush
Interobserver reliability (objectivity) of atlanto-occipital appositional measurement and condylar slope and convexity measurements on Blair Oblique view spinographs.
Third Annual Convention and Educational Seminar, Wm. G. Blair Chiropractic Society, Inc., October 7-8, 1988, Somerville (Boston) Mass, (Earlier version presented as Objectivity (Interobserver reliability) of atlanto-occipital articular appositional measurement and slope angle measurement in Blair upper cervical technique. Fourth Annual Upper Cervical Conference, Dec. 4-6, 1987, Life Chiropractic College, Marietta, GA.

10.   Addington, E.A., et al., in progress.

11.   Addington, E.A., and R.W. Muncy. Estimated number of distinct upper cervical adjustments in Blair technique. Fourth Annual Convention and Educational Seminar, Wm. G. Blair Chiropractic Society, Inc., October 28-29, 1989, Kansas City, Mo.

12.   Addington, E.A., M. Bantich, R.I. Morrison, C. Roberts. Interobserver reliability of neural canal diameters and neural canal relationships in A-P open mouth cervical spinographs. Tenth Annual Conference, William G. Blair Chiropractic Society, Inc., August 4-6, 1995, Seattle, WA.


Thanks to Ed Owens @ Sherman College's Research Department for rendering this article. Thanks also to Dr. Art Addington,   the author for permission to republish and to Bill Meeker, D.C.,   the past-president of the Consortium for Chiropractic Research for the right to republish the Appendix,   which was presented in the Proceedings of the Sixth Annual Convention on Research and Education:   Emphasis on Consensus. June 21-23, 1991,   Monterey, Calif. Program Sponsors:   Consortium for Chiropractic Research,   Calif. Chiropractic Association,   ACA Council on Technique.


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