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Sharpen Your Skills!
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 Modified Prill Cervical Leg Check Protocol Michael Burcon, DC Edward Owens, DC ABSTRACT This interactive research presentation tested the reliability of the first step, the modified Prill leg check cervical protocol, of the Burcon Cervical Specific three step system. The fist step determines which cervical vertebra to adjust. The second step is x-ray analysis, to determine how to adjust that vertebra. The third step is the adjustment, followed by a fifteen minute rest and post check to validate that the adjustment was effective and to check to see if there is another involved segment. Dr. Burcon presented the protocol in a forty-five minute Power Point presentation at the 11th Annual Vertebral Subluxation Research Conference, hosted by Sherman College of Straight Chiropractic. Twelve of the forty attending doctors participated in designing and performing the research project. Dr. Owens compiled the data that night, and presented the results for discussion the following morning. Intraexaminer repeatability tested very good, while interexaminer repeatability tested excellent. Key Words: Blair Chiropractic Technique, Pierce Results System, Prill Spinal Analysis Technique, Derifield-Thompson Technique, Activator Methods, cervical syndrome, cervical subluxation, specific adjustment Introduction Burcon Cervical Specific Protocol is a new chiropractic technique being developed as a combination of the Blair Chiropractic Technique (1) used to analyze and adjust the upper cervicals, and the Pierce Results System (2) used to analyze and adjust the lower cervicals. A modified version of the Prill Chiropractic Spinal Analysis Technique (3) is utilized to determine which cervical vertebra to adjust. The need for a new technique came from observations made in practice by Dr. Burcon. He found that x-rays forwarded from full spine chiropractors rarely captured the atlanto-occipital articulations; therefore, no atlas subluxation listing could be derived. Furthermore, most upper cervical specific chiropractors assumed that unbalanced legs always indicated an upper cervical subluxation. Most upper cervical techniques assume that a good upper cervical adjustment will work it’s way down to the sacrum, correcting misalignments along the way. Burcon believes that this is possible, but often unrealistic when there is a significant kink between two vertebrae in between the two ends of the spine. For instance, many whiplash patients have a significant kink in the area of C5. Burcon found that these patients failed to hold their upper cervical adjustments until a lower cervical adjustment was performed. (4) The purpose of this project was to assess the repeatability of the first step of the Burcon Cervical Specific Protocol, the modified Prill Chiropractic Spinal Analysis Technique. The second and third steps, x-ray analysis and specific adjusting technique, will be addressed in future papers. Dr. Prill does not approve of x-rays for chiropractic analysis. He believes that his challenges to individual vertebra are reliable enough not to warrant the need for films. (3) Dr. Burcon believes that challenges are approximately eighty percent effective, therefore not reliable enough to stand on their own. Dr. Prill also feels that arm checks are more reliable than leg checks. The Blair Chiropractic Society first did this modification from arms to legs because leg length analysis was already being performed in their protocol. Burcon has furthered modified this technique to also include the lower cervicals. Dr. Prill’s bio-electromagnetic theory (Peizo-Electric Effect) states that when a nerve circuit suffers interference from a vertebral subluxation, the frequency and polarity is altered and no longer in harmony with the balance of the nerve system resulting in structural distortion and aberrant physiology. The neuromuscular system becomes hypertonic on one side and hypotonic on the other. This physiological imbalance is manifested by apparent arm and leg length differentials. The negative polarity is found on the side to which the vertebra has subluxated. The negative side of the subluxation becomes contractive and restrictive in motion, while the other side becomes more expansive and mobile. (3) Several authors hypothesize that unloaded leg length inequality may be caused by abnormal contraction or shortening or the quadratus lumborum muscle, affecting pelvic biomechanics. (5) This muscle originates at the iliac crest and iliolumbar ligament, and inserts in the lower border of the twelfth rib and transverse process of the first four lumbar vertebrae. Together with the psoas major, it forms the posterior-lateral aspect of the abdominal wall. Upper cervical theory hypothesizes a correlation between upper cervical subluxation and leg length inequality. (6) Upper cervical theory hypothesizes a connection between upper cervical subluxation and leg length inequality. According to John Grostic, DC the atlas subluxation causes tractioning of the spinal cord via the dentate ligament, causing venous blockage and hypoxia in the spinocerebeller tract. (7) This tract is the main conduit for sensory information on muscle tone, joint position and lower motor centers to the higher centers of the brain, resulting in increased muscle tone, hypertonicity and the functional short leg. G Knutson, DC theorizes atlanto-occipital intra-articular fat pad impingement, caused by the atlas subluxation, contracts the suboccipital muscles, activating a tonic neck reflex. This reflex causes chronic tension in the extensor muscles, which results in a functional short leg. (8) Proprioceptive/mechanoreceptive insult theory suggests that cervical subluxation causes mechanoreceptor stimulation and aberrant afferent input into the spinal cord, inducing changes in neural output, resulting in a functional or contractured leg. (8) Spinal cord input from mechanoreceptor stimulation is concentrated in the cervicals. Lateral flexion of the head is associated with shortening of the contralateral leg. Rotation of the head is associated with ipsilateral leg shortening. Burcon speculates that all of these theories come into play while the body seeks an analgesic posture to relieve brain stem pressure and level the eyes to the horizon. In his opinion, the body will sacrifice the low back to protect the upper cervicals. This is why many chiropractic and medical techniques do not provide long lasting relief for low back pain patients. The compensation is being addressed, not the cause. Research on the repeatability of leg checks used as evidence of vertebral subluxation has shown mixed reviews. A study was conducted by Activator Methods to determine whether prone leg check in association with an isolation test maneuver was reproducible. Two examiners evaluated seventy-two subjects on separate occasions for the presence of C1 subluxation. Concordance was assessed by the Kappa statistic, and interexaminer percentage of agreement was compared. The results indicated good reliability. (9) In contrast, a reliability study was conducted by the Research Department at Western States Chiropractic College to determine reliability of detecting leg alignment change reactivity attributed to a rotary articular pressure challenge on the posterior aspect of the lateral mass of C1. This procedure performed on forty-two participants was not found to be viable for identifying vertebrae for adjustment. (10) In Burcon’s practice, one hundred consecutive patients were accessed using this protocol during their first six visits, for a total of six hundred visits. Out of four hundred and ninety positive tests for adjusting a cervical vertebra, four hundred and eighty two tested negative after adjustment and fifteen minute rest. Additionally, ninety-one of the one hundred patients reported that, in their opinion, their chief complaint was eliminated or under control on the sixth visit. (11) Methods The reliability study was designed and carried out during a weekend educational conference with attendees serving as co-designers, assessors and subjects for the study. The conference included a module on reliability study design, with discussions of such issues as blinding, sample size, pre-test training and statistical analysis. Another module of the conference was a hands-on workshop in the Burcon Protocol taught by its developer. Hence, the project had a distinct educational component, as well as providing information about the reliability of the protocols. After a short discussion on the purpose and aims of the study, we decided to use a repeated measures design with 7 subjects and 5 examiners. The subjects would remain in place on the test benches all in the same room for the duration of the tests. Each examiner would move through the room, checking each subject twice in a round robin fashion. Two participants helped coordinate the study, making sure data sheets were provided when needed, conducting examiners to open tables, ensuring that no communication of findings was possible between examiners and checking to be sure that all examiners tested all subjects. It was felt that the testing would be complex enough that the examiners would be unable to recall previous findings on the same subject. The doctors were all practicing chiropractors with between 3 and 22 years of experience. The subjects were also chiropractors, and were asymmetric at the time of the study. Each subject was assigned a number for recording purposes, which was pinned to his or her back. Informed consent was administered in group fashion. No adjustments were performed and there was no anticipated risk, other than fatigue or muscle soreness from repeated testing. Data sheets were developed with fields for patient ID#, examiner initials and the 10 leg check findings. Leg check findings were estimated and recorded to the nearest 1/8”. In addition to the leg check findings, examiners were asked to indicated which segment(s) they would be likely to adjust based on those findings. Derifield/Thompson Cervical Syndrome- Hold patient’s shoes with thumbs under the heel, while applying very mild cephalic pressure. Lift the legs one inch off from the table, keeping the shoes one inch apart. Compare the welts to estimate the leg length differential. Notate differential of short leg to closest 1/8 inch. Instruct patient to slowly turn their head to the right, then to the left. If the legs change length only while turning to the right, notate the amount of change as a right cervical syndrome (RCS). If the legs change length only while turning to the left, notate the amount of change as a left cervical syndrome (LCS). If the leg length changes while turning the head in both directions, notate the total amount of change as a bilateral cervical syndrome (BLCS). If there is no change in leg length when the head is turned, there is no cervical syndrome. Shambaugh, et al. reported on a reliability and validity test of the Derifield/Thompson test for cervical subluxation. The researchers showed that leg length inequality (LLI) of 3 mm was reliably detectable, and that there were statistically significant changes in LLI when the patient’s head was rotated. They did not show, however, that massage or cervical adjustments could produce a significant change in the LLI. While Shambaugh et al (and the JMPT editor) caught quite a bit of flack in response to their reporting on the statistical analysis; they later provided a more complete report of the data analysis including a table of experimental data. The statistical analysis included a calculation of Chronbach’s Alpha as an indication of concordance. This calculation is based on the Analysis Variance and is equivalent to one form of the Intraclass Correlation coefficient (ICC), which is frequently reported in the literature today as useful for reliability estimation. Burcon considers a cervical syndrome the most significant indicator of an upper cervical subluxation. (12) With practice, you can learn to differentiate an atlas subluxation from an axis subluxation by the nature of the movement when the leg lengths change. With an atlas subluxation, the leg will come straight down, while with an axis subluxation, the leg will laterally rotate out and back in slightly as the leg comes down. Modified Prill Leg Checks This series of checks consists of instructing the patient to contract a certain set of muscles while the doctor restricts the movement. The resistance pressure should be held about three seconds. Immediately after the resistive maneuver, any leg length inequality is observed. The muscle reflex response often lasts only a short time. While you do not have to rush the tests, they should be done in a timely manner. A word of caution if your patient has ever been to a chiropractor that utilizes applied kinesiology. These tests are designed to challenge the muscles that hold you upright in gravity, not your skeletal muscles. You are working with the peripheral nervous system and only light pressure by both doctor and patient is required, about one pound. Emphasize that these movements need to be performed gently and steadily. Leg length inequality of 1/8 inch or more indicates a positive test for that level. Notate positive tests for the modified Prill leg checks as follows: Leg Length Inequality Notation Example < 1/8 inch None1/8 inch – ½ inch List segment C1>1/2 inch – 1 inch List segment+ C1+ >1 inch- 1 ½ inches List segment++ C1++ >1 ½ inches List segment+++ C1+++ Upper Cervicals C1 (Atlas) Subluxation Test: Instruct the patient to gently and steadily raise both feet, with knees locked, while you lightly rest your hands on their heels. This correlates to the flexion and extension of the skull on atlas. C2 (Axis) Subluxation Test: Instruct the patient to gently and steadily pull their feet together, while you lightly hold the insides of their heels apart. This correlates to the rotation of axis within atlas. Sacral Occipital Technique categorizes neural feedback loops of the spine and lists them in groups. (13) Complex I includes atlas and the 5th lumbar. The vertical C1 test brings the hamstrings into play, which will test the L5 nerve root. The radial C2 test will allow the Tibialis Anterior to react, invoking the L4 nerve root, which is linked with axis in Subluxation Complex II. (14) Lower Cervicals C3 Subluxation: Instruct the patient to pull their legs together, while you hold the legs apart. This brings the adductors of the thigh into play; the main innervations are from L3, which is coupled with C3 in SOT Complex III. C4 Subluxation: Instruct the patient to bring their legs apart, while you hold the legs together. This must be done gently so that there is a locking of the pelvis by the Psoas Major, innervated by L2 nerve roots, corresponding to SOT IV. C5 Subluxation: Instruct the patient to put their arms out straight like airplane wings. Place your hands on top of their biceps and instruct them to raise their arms towards the ceiling. C6 Subluxation: Instruct the patient to put their arms out straight like airplane wings. Place your hands on their Brachioradialis muscles, instruct the patient to raise their arms towards the ceiling. C7 Subluxation: Instruct the patient to put their arms out straight like airplane wings. Place your hands under their Triceps, instructing the patient to push their arms down towards the floor. The tests for C5, C6 and C7 resemble the Activator Methods assessment, which looks for reactive changes in leg length difference with certain changes in body position or muscle contraction. This method has been tested to some extent for reliability and validity. www.activator.com Assessment: Deciding which cervical vertebra to adjust first. 1. If one individual segment checks more positive (leg goes shorter) than any other segment, adjust that segment first. 2. If more than one segment ties, adjust the uppermost segment first, i.e., if you tested C1+ and C5+, adjust C1. 3. Rest the patient for fifteen minutes in supine position. 4. Repeat all leg checks. 5. If you have any positive checks, go back to step one and repeat. The most common combination you will see will be a positive C1 and C5. An atlas adjustment will clear out the C5 approximately fifty percent of the time. My atlas adjustments hold an average of two months. It typically takes about six lower cervical adjustments before that segment will hold. Statistical Analysis Data from the data sheets was tabulated overnight and stored in an Excel spreadsheet for the graphing and exploration. The results were presented for discussion at the conference the next morning. Scatter plots were used to explore the relationships between findings and tables were ported to SPSS for Windows for calculation of Intraclass Correlation Coefficients Acknowledgements We would like to thank the research department at Sherman College of Straight Chiropractic, Spartanburg, SC, for allowing us to test the modified Prill leg check protocol during the 11th Annual Vertebral Subluxation Conference. References 1. Overview of Blair Cervical Technique, Council on Chiropractic Practice, Chandler, Arizona, October 2-3, 1995, www.BlairChiropracticSoc.org. 2. Painter, DC, F, Pierce Results System, The Chiropractic Resource Organization, www.Chiro.org. 3. Prill, DC, C, The Prill Chiropractic Spinal Analysis Technique, C.E. Enterprises, Peoria, Illinois, 2000, www.PrillChiropractic.com. 4. Burcon, DC, M, Parkinson’s Disease, Meniere’s Syndrome, Trigeminal Neuralgia and Bell’s Palsy: One Cause, One Correction, Dynamic Chiropractic, May 19, 2003, Volume 21, Issue 11, www.chiroweb.com. 5. Knutson, DC, G, Owens, DC, E, Erector quadratus lumborum muscle endurance tests and supine leg-length alignment asymmetry: An observational study, J Manipulative Physiol Ther. 6. Knutson, DC, G. An Examination of the Premises for Chiropractic Specific Upper Cervical Technique, Journal of Vertebral Subluxation Research, Feb 7, 05, pp 1-7. 7. Grostic, DC, J, Dentate ligament-cord distortion hypothesis, Chiro Res J, 1988;1(1):47-55. 8. Knutson, DC, G, Tonic neck reflexes, leg length inequality and atlanto-occipital fat pad impingement: an atlas subluxation complex hypothesis, Chiro Res J, 1997;4:64-76. 9. Youngquist MW, Fuhr AW, Osterbauer PJ. Interexaminer reliability of an isolation test for the presence of an upper cervical subluxation. J Manipulative Physiol Ther 1989; 12:93-97. 10. Hass M, Peterson D, Panzer D. Reactivity of leg alignment to articular pressure testing: evaluation of diagnostic test using a randomized crossover clinical trial approach. J Manipulative Physiol Ther. 1994 Sept:17(7): 11. Burcon M. Upper Cervical Protocol for Ten Meniere’s Patients. Upper Cervical Subluxation Complex. Ericksen K, Lippincott, Williams & Wilkens, Baltimore, MD, 2004. 12. Jackson, R. The cervical syndrome. Ed 2. Charles C Thomas Publisher, Springfield, IL, 1958. 13. Hochman J. Sacro-occipital technique: The categorization procedure (part II) Today’s Chiropractic, May-June, 1996, Vol 25, No 3. 14. Cooperstein MA. Sacral-occipital technique, Chiropractic Technique, Aug 1996, Vol 8 No 3. |
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