Non-specific low back pain (LBP) is a major health problem affecting a substantial portion of the population. The current treatments offered for non-specific LBP are oftentimes unsuccessful because the acting mechanism(s) of most treatment options are unknown. Obtaining a better understanding about the acting mechanism behind existing treatment options is, therefore, essential for the improvement of non-specific LBP treatment and management. The objective of this study was to gain a more comprehensive understanding about the acting mechanism of high velocity low amplitude spinal manipulative therapy, specifically the impact that high velocity low amplitude spinal manipulative therapy may have on the active and passive spinal musculoskeletal stabilizing subsystems along with the resultant spinal stability for healthy participants. A pre-post intervention study design completed by six healthy participants was used to quantify changes in the above noted aspects of spinal stability using a series of tests performed both before and after six sessions of high velocity low amplitude spinal manipulative therapy. The tests included seated balancing tests, lower back range of motion tests, and stress relaxation test. The six sessions of high velocity low amplitude spinal manipulative therapy did not significantly affect any of the test measurements among our healthy participant group.

Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic, Department of Chiropractic, Durban University of Technology, Durban, South Africa, 2015. / Background: Spinal manipulative therapy (SMT) is a commonly used treatment for many musculoskeletal conditions although the exact mechanism explaining its effectiveness is not well understood. Several studies have investigated the effect of SMT on the paraspinal muscles where neuromuscular effects have been observed, however few studies have assessed whether these changes result in a change in the functioning of the paraspinal muscles. This study aimed to determine the effect of lower thoracic spinal manipulation compared to a placebo intervention on lumbar extensor muscle endurance in asymptomatic participants. Methodology: This was a quantitative, pre-test post-test, placebo controlled trial involving 40 male participants between the ages of 20 and 40 years. The participants were randomly allocated to either the lower thoracic spinal manipulation group or a placebo group. Manipulation was delivered using the Impulse Adjusting Instrument®. Objective measures included lumbar spinal range of motion, a paraspinal muscle endurance test, and surface electromyography readings. Subjective measures were the verbalisation of pain and/or discomfort during the paraspinal muscle endurance test. IBM® SPSS® statistics version 21 and STATA 11 were used to analyse the data. A p-value of <0.05 was considered statistically significant. Results: There were no statistically significant differences between the groups in terms of subjective and objective measurements. A trend of treatment effect was observed for paraspinal muscle endurance where the intervention group showed noticeable improvements in endurance scores. Conclusion: Further studies need to be conducted to determine if the trends observed would occur in a larger study population.

M.Tech. (Chiropractic) / Purpose: The aim of this study was to look at the effectiveness of massage with MYO₂ gel in conjunction with Spinal Manipulative Therapy (SMT) for the treatment of patients with posterior mechanical neck pain, with regards to pain, disability and cervical spine range of motion. The effect of these treatments was evaluated using a questionnaire consisting of Visual Analogue Scale (VAS) and a Vernon-Mior Neck Pain and Disability Index Questionnaire, and by measuring cervical spine range of motion using a cervical range of motion (CROM) measuring device. Method: 30 participants with posterior mechanical neck pain were randomly divided into two groups based on the order they start the study in. Group A – control group, received SMT to the cervical spine, followed by massage with ultrasound gel over the upper trapezius muscle and the area of the posterior neck musculature. Group B – experimental group, received SMT of the cervical spine, followed by massage with MYO₂ gel over the upper trapezius muscle and the area of the posterior neck musculature. Participants were treated six times out of a total of seven sessions, over a maximum three week period. Procedure: Subjective data was collected at the beginning of the first and fourth and seventh consultations. This was done by means of a Visual Analogue Scale (VAS) and a Vernon- Mior Neck Pain and Disability Index Questionnaire in order to assess pain and disability levels. Objective data was collected at the beginning of the first, fourth session, and seventh consultation by means of measuring cervical spine range of motion using a cervical range of motion (CROM) measuring device. Analysis of collected data was performed by a statistician from STATKON; a department of the University of Johannesburg. Results: When comparing the VAS of the initial with the final consultation it showed a statistically significant difference in both groups. This indicated that both interventions were effective in decreasing the perceived level of neck pain (VAS score). When comparing the Neck Pain and Disability Index of the initial with the final consultation it showed a statistically significant difference in both groups. This indicated that both interventions were effective in decreasing neck pain and disability of the cervical spine. When comparing the Cervical Range of Motion (CROM) of the initial consultation with the final consultation it showed a statistically significant improvement in both groups in all directions of motion. Both groups resulted in an increase in range of motion over time. Group B had a greater average CROM percentage increase of 28.60% average compared to Group A which had an average percentage increase of 22.25%.

La manipulation vertébrale (MV) est l'une des options dans le traitement des douleurs d'origine neuromusculosquelettique. Ses indications ont été identifiées à partir de l'expérience des professionnels qui l'utilisent, ainsi que des études épidémiologiques autour de ses résultats cliniques. Cependant, son mécanisme d'action précis demeure à ce jour inexpliqué.La littérature scientifique sur ce sujet est incomplète, éparse et confuse. Certains auteurs et professionnels proposent des hypothèses des mécanismes d'action neurobiologiques et d'autres biomécaniques. De plus, l'étude de la douleur rend la situation difficile en raison de la complexité des situations cliniques et des traitements associés dont les patients bénéficient. C'est la raison pour laquelle l'objectif de cette thèse est d'étudier si la MV a un effet sur la douleur provoquée de manière expérimentale. Si tel est le cas, il importe de savoir s'il est systémique ou locorégional et dans cette dernière hypothèse, si ce résultat est le produit d'une action directe de la MV sur la douleur ou secondaire à une amélioration du mouvement. N'ayant pas trouvé d'étude englobant la problématique mixte des effets de la MV sur la douleur et le mouvement, nous avons procédé à deux revues systématiques et critiques de la littérature scientifique ; l'une a porté sur son effet sur la douleur et l'autre sur l'amplitude du mouvement des segments vertébraux. Dans la première, nous avons rassemblé 22 articles décrivant 43 essais cliniques montrant un effet hypoalgésique de la MV au niveau locorégional, mais les résultats diffèrent selon la manière dont la douleur a été provoquée. Nous n’avons pas pu tirer de conclusion sur l'action systémique de la MV du fait de la qualité des articles sur ce sujet. Quant à la revue de la littérature réalisée sur l'effet de la MV sur l'amplitude du mouvement, l'étude de 15 articles ne nous a pas permis de prouver l'efficacité de cette technique pour augmenter l'amplitude des mouvements segmentaires, malgré des limitations à prendre en considération, notamment le fait que ces études ont été réalisées sur des volontaires sains et non sur des patients avec une mobilité réduite. A partir de là, nous concluons que l'effet de la MV sur la douleur est plutôt direct, et défendons la thèse que l'hypoalgésie induite par la MV permet l'amélioration et la récupération de la fonction de mouvement, et non l'inverse.Cependant, même si nous répondons à nos questions de recherche, ces réponses demeurent partielles et le sujet reste à approfondir. Nos deux revues indiquent qu’il reste à clarifier : les mécanismes exacts des effets de la MV sur la douleur, la durée des effets, les rapports "dose/effet", l'identification des techniques les plus efficaces, ou encore, sur le ciblage plus fin des patients à traiter. Il en est de même en ce qui concerne l'étude de l'effet de la MV sur l'amplitude du mouvement, où il manque notamment des études réalisées sur des patients et des personnes présentant des mouvements limités. Des améliorations sont également à prévoir dans la coordination des chercheurs les rassemblant autour d'une politique de recherche partagée sur le long/moyen terme, et à partir d'un consensus méthodologique, particulièrement en termes de suivi des essais, d'unités de mesures, de précision des critères de qualité des essais, de promotion de méta-analyses, etc. Au total, si la MV semble avoir un effet direct sur la douleur, il n’en demeure pas moins que la connaissance détaillée de ses mécanismes et des modalités d'application dans la pratique clinique reste à approfondir, ce qui pourrait devenir un véritable enjeu pour la communauté des chercheurs, des enseignants et des cliniciens. / Spinal manipulative therapy (SMT) is one of the treatments used to reduce musculoskeletal pain. Some clinical studies have shown that it really has a pain reducing effect but the indications for when it should be used is mainly based on clinical experience and logic. Further, although SMT is widely used, the precise mechanisms of action that can explain how it works, are unknown.We noticed that the scientific literature on this subject is incomplete, scattered and confused. In relation to the mechanisms, some authors propose a number of neurobiological mechanisms (such as a direct reduction of pain) whereas others are convinced that the mode of action is biomechanical (such as improved range of motion). For this reason, when trying to find out if SMT has a pain reducing effect, a better alternative is to start with healthy people, provoke a pain experimentally, perform the SMT, and measure their pain, to see if it has improved with the “treatment”. If it would be possible to see if SMT does have a pure pain reducing effect, then it would be important to find out if this effect is only regional, in the area of the manipulation, or if this effect is systemic. Also, none of the authors who proposed the biomechanical theory offered any evidence that improved movement results in less pain, but then, the opposite pathway (reduce pain first, better movement after) has not been shown either, by these proponents of theories. For this reason we decided to study the already existing scientific literature in a critical and systematic fashion.Unfortunately, we did not find any study including the mixed problem of the effects of SMT on pain and movement, we therefore performed two systematic reviews of the scientific literature: one focused on its effect on experimental pain and the other on its effect on the range of motion (ROM) of the vertebral segments. In the first one, we collected 22 articles describing 43 trials showing an hypoalgesic effect of the locoregional level. Interestingly, the results differ depending on how the pain was provoked. We were not been able to reach a conclusion on the systemic action of the SMT because of the lack of quality of articles on this topic. Concerning the literature review on the effect of SMT on ROM, the review of 15 research articles did not allow us to « prove » the effectiveness of this technique to increase the range of segmental motion. There were some limitations with these studies, such as the fact that they had been performed in healthy volunteers and not in people with reduced mobility. In sum, we could conclude that the effect of SMT on pain has been clearly shown, which supports the hypothesis that the hypoalgesia induced by SMT allows the improvement and recovery of function of movement, and not the inverse. These results have been reported in our two scientific articles.However, even if we were able to obtain answers to our research questions, these answers are incomplete and the subject remains to be further explored. There are still questions that remain to be clarified, such as: What are the exact effects of SMT on pain mechanisms? How long does the effect remain ? Is there a " dose / effect "? Which are the most effective SMT techniques? and How should patients be best targeted for this treatment ? Does SMT have an effect on ROM on people with limited movement?Finally, a coordination of research is necessary to move forward more effectively. Researchers would need to gather around a shared policy in relation to the medium / long term research, and from a methodological consensus. In conclusion, SMT does seem to have a direct effect on pain. However, we need some more and detailed knowledge of the mechanisms and procedures before we can really apply this knowledge efficiently in clinical practice. No doubt, this could become an important issue for the community of researchers, teachers and clinicians.