Introducing the External Link Model for Studying Spine Fixation and Misalignment: Part 2, Biomechanical Features
| Autor: | Charles N.R. Henderson, Gregory D. Cramer, Qiang Zhang, James W. DeVocht, Jaeson T. Fournier |
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| Rok vydání: | 2007 |
| Předmět: |
Male
musculoskeletal diseases medicine.medical_specialty External Fixators Radiography Residual stiffness Link model Rats Sprague-Dawley Reference Values Linear regression medicine Animals Fixation (histology) Subluxation Orthodontics Manipulation Chiropractic business.industry Stiffness Bone Malalignment musculoskeletal system medicine.disease Chiropractic Spine Biomechanical Phenomena Rats body regions Disease Models Animal Linear Models Physical therapy Chiropractics medicine.symptom business |
| Zdroj: | Journal of Manipulative and Physiological Therapeutics. 30:279-294 |
| ISSN: | 0161-4754 |
| DOI: | 10.1016/j.jmpt.2007.03.002 |
| Popis: | Objectives The purpose of this study was to characterize intervertebral stiffness and alignment changes in the external link model and evaluate it as an experimental mimic for studying the chiropractic subluxation. Method A controlled test-retest design was used to evaluate rats with spine segments linked in 3 alignment configurations and controls that were never linked. Dorsal-to-ventral spine stiffness was measured with a load platform, and flexion/extension misalignment was assessed on lateral radiographs obtained with a spine extension jig. Descriptive statistics were computed for study groups, and multiple linear regression models were used to examine all potential explanatory variables for the response variables “stiffness” and “joint position.” Results Rats tested with links in place had significantly higher dorsal-to-ventral stiffness in the neutral configuration than rats in the flexed configuration. This difference remained after the links were removed. Stiffness after link removal was greater for longer linked periods. Surprisingly, stiffness after link removal was also greater with longer unlinked periods. Longer linked periods also produced greater misalignments during forced spine extension testing. Although link configuration was not a statistically significant predictor of misalignments, longer times after link removal did produce greater misalignments. Conclusions This study suggests that the external link model can be a valuable tool for studying the effects of spine fixation and misalignment, 2 cardinal features of what has been historically described as the chiropractic subluxation. Significant residual stiffness and misalignment remained after the links were removed. The progressive course of this lesion is consistent with subluxation theory and clinical chiropractic experience. |
| Databáze: | OpenAIRE |
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