Abstract
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.