Distraction Manipulation of the Lumbar Spine: A Review of the Literature
Bibliographic record
Abstract
Gay et al1Gay RE Bronfort G Evans RL Distraction manipulation of the lumbar spine: a review of the literature.J Manipulative Physiol Ther. 2005; 28: 266-273Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar discussed nucleus pulposus movement during flexion and extension of the lumbar spine, citing Fennell et al2Fennell AJ Jones AP Hukins DWL Migration of the nucleus pulposus within the intervertebral disc during flexion and extension of the spine.Spine. 1996; 21: 2753-2757Crossref PubMed Scopus (85) Google Scholar as stating that the nucleus moves anterior on extension and posterior on flexion. Full study of the Fennell paper, however, shows a different finding. Fennell studied nuclear motion on magnetic resonance imaging of 3 patients—1 normal 18-year-old patient with no history of low back pain and two 25- and 46-year-old patients with low back pain history. The 18-year-old patient with no back pain did show anterior nuclear movement on extension and posterior motion on flexion; however, the 2 patients with a history of low back pain showed the L4-L5 disk to move anteriorly during flexion. The nucleus spread within the L4-L5 disk during flexion instead of migrating posteriorly. Fennel explained the 2 unexpected results in the painful spines as possible disk degeneration etiology. Gay et al1Gay RE Bronfort G Evans RL Distraction manipulation of the lumbar spine: a review of the literature.J Manipulative Physiol Ther. 2005; 28: 266-273Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar also discussed the study of Beattie et al3Beattie PF Brooks WM Rothstein JM Sibbitt WL Roberts RA MacLean T et al.Effect of lordosis on the position of the nucleus pulposus in supine subjects: a study using magnetic resonance imaging.Spine. 1994; 19: 2096-2102Crossref PubMed Scopus (66) Google Scholar about 20 healthy young women with lumbar spine magnetic resonance imaging in extension, and Gay et al stated that they found that the posterior margin of the nucleus in the normal lower lumbar disk tends to move anteriorly with extension and posteriorly with flexion, and there was no anterior nucleus movement. Again, that is not a complete explanation of Beattie's finding. He found that in normal disks without degeneration, the posterior disk margin increased between the posterior margin of the nucleus pulposus and the posterior portion of the vertebral bodies of the normal disks of healthy young females during extension motion. However, 8 of the 20 subjects had at least one degenerative disk in the lower lumbar spine. The nucleus of the degenerative disks did not move the same as normal disks. Degenerative disks deform differently from nondegenerative disks. Other similar studies have shown that the nucleus pulposus moves posterior or does not move with extension movement.4Vanharanta H, Ohnmeiss D, Stith W, Rashbaum R, Hochschuler S, Guyer R. et al. Effect of repeated trunk extension and flexion movements as seen by CT/discography orthopedic transactions. Journal of Bone and Joint Surgery 10 Shattuck Street, Boston, Massachusetts, 12115/Volume XIII, Number 1,1987, pg 28. Poster Exhibit, North American Spine Society, Banff, Canada, June, 1987.Google Scholar, 5Gill K Videman T Shimizu T Mooney V The effect of repeated extensions on the discographic dye patterns in cadaver lumbar motion segments.Clin Biomech. 1987; 2: 205-210Abstract Full Text PDF PubMed Scopus (7) Google Scholar, 6Roaf R A study of the mechanics of spinal injuries.J Bone Joint Surg. 1960; 42B: 810Google Scholar, 7Schultz AB Warwick DN Berkson MH Nachemson AL Mechanical properties of human lumbar spine segments. Part 1. Response in flexion, extension, lateral bending and torsion.J Biomech Eng. 1979; 101: 46-52Crossref Scopus (285) Google Scholar Reading the article of Gay et al., one is led to believe that the nucleus pulposus always moves anterior on extension and posterior on flexion, when in fact that is not the case. Gay et al accurately cite literature showing that stenosis is induced into the vertebral and the osseoligamentous canals by extension, which causes posterior annulus protrusion, ligamentum flavum buckling, facet imbrication, and narrowing of the posterior disk space. Hopefully, I have augmented the findings as given in the important paper of Gay et al. The movement of the nucleus pulposus is unpredictable in the degenerated disk. As chiropractors, we treat degenerated disks and need to be aware of their behavior. The intervertebral disk is probably the most common source of chronic low back pain.8Kuslich SD Ulstrom CL Michael CJ The tissue origin of low back pain and sciatica.Orthop Clin North Am. 1991; 22: 181-187PubMed Google Scholar Tolerance testing before applying manipulation to the patient's spine is prudent because of the unpredictable nature of the disk. For safety, I teach that the maximum angle of flexion used is 6° when long y-axis decompression is applied to the motion segment. At that degree, our research has shown that the ligament stresses are well within normal limits so that damage will not occur to the stability of the segments. This small 6° flexion angle used may diminish the value of this discussion, but nevertheless, we must maintain correct biomechanical concepts for future study. Response to Letter to the Editor by CoxJournal of Manipulative & Physiological TherapeuticsVol. 29Issue 1PreviewI thank Dr Cox for pointing out the lack of clarity in our article regarding nucleus pulposus behavior during flexion and extension. The paragraph he referred to addresses normal nucleus pulposus motion. Both the article of Beattie et al1 and the article of Fennel et al2 have contributed to our understanding of how normal disks respond to flexion and extension. Dr Cox is correct; current evidence suggests that abnormal disks do not respond to flexion and extension in a predictable pattern. This was best illustrated by Schnebel et al3 in their study of flexion and extension after diskography. Full-Text PDF
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.008 | 0.007 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.003 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".