The Blair Technique
The Blair technique utilizes neurological tests, heat sensitive instrumentation and other means for detecting when the vertebral subluxation is present or absent. The adjustment is administered only when nerve pressure is present.
The Blair technique utilizes precise x-rays of the upper cervical area to determine which way the vertebrae has misaligned so that a precise and specific adjustment may be tailored and administered to that individual.
The Blair Technique has as its exclusive concern the analysis and correction of the subluxations of the cervical vertebrae, and as its only goal the consequent cervical spine.Subluxated articular misalignments are analyzed as they displace the nueral 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. Biochemical and 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.
The presence of nerve interference in the cervical spine is determined by the observation of both a persistent differential parasipinal 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 TI spinous process to about the superior nuchal line. At least two, and preferably three, consecutive readings, taken on separate days, a-re required to determine the patient's individual, characteristic heat pattern indicative of nerve interference. The individual's pattern is defined by those unilateral heat deflections ("breaks") which are invariantly present on each of the pre-adjustive readings. Except in the case of a new injury changing the misalignment, the patient is not readjusted subsequent to the initial adjustment until the original dermothermographic pattern has returned, in the presence of a functional 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-Derfeid procedures of modified Prill procedures, or both, and some practitioners use the supine spinal 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.
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 adjuster and incorporating a 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 vertebra 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 Cl. 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 atlantooccipital articulations. Adjustments of atlas require the doctor to orient along up to three angular measurements of C I 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 or contralateral 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 tow adjacent segments have misaligned in opposite directions, opposing contacts (using both hands) may be made on the two segments simultaneously.
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 Mount 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
Conference on Research and Education
Monterey, California June 21-23, 1991
Presenter: E.A. Addington, M.A., D.C.
Blair Chiropractic Clinic
The technique developed and taught by the late William G. Blair, D.C., Ph.C., F.I.C.A., is an exclusively cervical technique that considers subluxations of Cl 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 derinothermographic 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 exact juxtaposition of adjacent articular surfaces at their osseous margins, while misaligned 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 the articulations. The articulation is therefore the most anatomically accurate place to assess the alignment of the vertebra.
Dr. Blair developed a two-stage system of visual spinographic analysis that 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 atlantooccipital and apopyhseal articulations. An articular series, which includes Blair Oblique Protractoviews of each atlanto-occipital articulation and a Blair lateral Cervical Stereoscopic view made at a specified degree of rotation and tube elevation, is used to determine cervical articular alignment. The Blair Protracto clamp, 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 the 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 the convergence any-les -representing the longitudinal axes) of the respective atlanto-occipital articulations according to a distinctive method originated by Dr. Blair. The Blair Princij2le 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 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 spinus 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 C2-4 articulations on the Blair Lateral Cervical Stereoscopic view. Some contemporary practitioners omit the scout Lateral Cervic view take 5-degree rotated Lateral Cervical Stereoscopic views 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 secured in Blair Protracto clamps 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 anterolateral than condyle margin), or underlapped (lateral mass margin less antero-lateral than condyle margin). These appositional judgments 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 of 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 interovserver 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 . 10). Convergence angles of left and right articulations, pooled together, showed a mean value of about 24.3 plus or minus 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 .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 interovserver 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) inb interobserver reliability due to slight differences in measurement methods. Interobserver reliability of articular determinations subjacent to atlas has not yet 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.
BLAIR CERVICAL SPINOGRAPHIC ANALYSIS REFERENCES
Reprinted by permission from the Proceedings of the Sixth Annual
Conference on Research and Education: "Emphasis on Consensus."
June 21-23, 199 1, Monterey, California.
Consortium for Chiropractic Research, California Chiropractic
Association, ACA Council on Technique.
COPYRIGHT 1991, CONSORTIUM FOR CHIROPRACTIC RESEARCH