M.Tech. (Chiropractic) / The purpose of this study was to compare the immediate effect of upper versus lower cervical manipulation on the vertebral artery blood flow in asymptomatic individuals. Thirty patients of both genders between the ages of 18-45 years of age, volunteered to participate in this study. Each participant presented with at least one upper and one lower rotary cervical facet restriction. Each participant was randomly placed into either Group 1 whom received upper cervical manipulation, or Group 2 whom received lower cervical manipulation. Any participants who presented with positive VBAI signs or symptoms were excluded from this study. The Medison SonoAce 8000 Ultrasound System was used to objectively measure the blood flow as close to C1-C2 region as possible, contralateral to the side of the adjustment contact. Three measurements were recorded in total which included neutral, pre-manipulation and post-manipulation. As this study included asymptomatic participants, no subjective data was collected. Statistical analysis was performed where the intragroup analysis was done using the Paired Sample t-test and inter-group analysis was done using the Independent Samples t-test to check for statistically significant results less than the p-value of 0.05. There were no statistically significant results found in Group 1 and Group 2 in isolation in the intragroup analysis as well as when compared in the intergroup analysis. Upper cervical manipulation resulted in a slight percentage increase in mean blood flow velocity. Lower cervical manipulation resulted in a decreased end diastolic blood flow velocity after manipulation which indicated the possibility of vertebrobasilar occlusion, however, it did not result in much change with regards to mean blood flow velocity. In addition, upper as well as lower cervical v manipulation had a minimally insignificant dilating effect on the diameter of the upper vertebral artery which may have been due to reflex vasodilation. This study demonstrated no statistically significant changes in isolation in the intragroup analysis as well as when compared in the intergroup analysis. Lower cervical manipulation did however have a moderate influence on the upper vertebral artery blood flow but overall was still less stressful in comparison to upper cervical manipulation. Additional studies are suggested to clarify these findings further.

<p> This pilot study was performed in order to examine the potential beneficial effects of cervical spinal manipulative therapy on volunteers suffering from post-concussive neck syndrome. The study of concussions and post-concussive neck syndrome is still a relatively new topic in the existing literature. Little research has been done in the area of spinal manipulation and the treatment of volunteers suffering from post-concussive neck syndrome, from a biomechanical standpoint.</p> <p> Forty-one volunteers who were suffering from post-concussive neck syndrome were recruited from McMaster University in Hamilton, Ontario to participate in the study. In order to assess the severity of neck complaints, the severity of their post-concussive symptoms and overall general health, the volunteers completed the Neck Disability Index, the Visual Analog Scale, the Standardized Assessment of Concussion and the Short Form-36 Health Survey. During testing sessions, volunteers were fitted with several light emitting markers placed strategically on the head, mid-back, sacrum and heels of the volunteers' footwear. Each volunteer would then walk on a treadmill for four separate five minute trials, after an initial familiarization period. The 3D position of these markers during gait were recorded by a rear-mounted kinematic data acquisition system (Optotrak 3020). After the initial five minute walk (trial 1), the volunteer was treated with a cervical spinal manipulation, and immediately resumed walking for the second trial on the treadmill. The volunteers performed four walking trials in total.</p> <p> Both manual and automated procedures were used to identify the multiple right-heel treadmill surface contacts during each five minute walk. Objective biomechanical outcome measures used in the study included relative phase measurements between the head and thorax in the transverse plane, the Biomechanical Efficiency Quotient and the Neck-Walk Index.</p> <p> Clinically significant results in relative measurements, post-intervention, were found when certain volunteers were removed (due to slow walking velocity). These differences can be attributed to the intervention of spinal manipulation which caused a significant increase in cervico-thoracic spinal motion, which appeared to decrease again at 35 minutes. This is clinically significant because it poses the theory that initial short-term biomechanical changes in the cervical spine are caused by SMT.</p> <p> Clinically significant results in the Biomechanical Efficiency Quotient were found when specific volunteers were removed. The results however, were in the opposite direction than was previously hypothesized. The reason for the increase in BEQ post-manipulation compared to pre-manipulation could be a result of the familiarization walking period before the initial trial. By allowing volunteers several minutes to get accustomed to walking on the treadmill, a learning effect had taken place, decreasing the variability in their gait in the initial pre-intervention trial. Although BEQ increased in the second and third trials, it decreased again at 35 minutes post-intervention, meaning the walking economy had once again increased.</p> <p> The specific intervention of cervical spinal manipulative therapy was hypothesized to change the variability of head movement disturbances during gait (Neck-Walk Index). No reference in the literature is made in relation to Neck-Walk Index and how it evaluates change in head carriage, post-intervention. This study suggests however, that although results approached significance, cervical manipulative therapy did not change biomechanical head carriage in this volunteer population.</p> <p> With respect to future studies, several recommendations have been made in this thesis which are aimed at increasing the clinical significance of the results. This would be done through the incorporation of more affected volunteers (increase in functional disability due to post-concussive neck syndrome), the incorporation of a more lengthy and specific treatment protocol (to sustain biomechanical and physical changes), and an increased treadmill walking velocity (to assess antiphasic movements more easily).</p> / Thesis / Master of Science (MSc)