Erhardt J, Windsor BA, Kerry R, et al. The immediate effect of atlanto-axial high velocity thrust techniques on blood flow in the vertebral artery: a randomized controlled trial [published online March 2, 2015]. Man Ther. doi:10.1016/j.math.2015.02.008. 

In 2009, the American Osteopathic Association’s House of Delegates reaffirmed their 2004 position paper¹ on osteopathic manipulative treatment to the cervical spine, endorsing the use of high-velocity, low-amplitude thrust by osteopathic physicians but calling for further research on the risk of vertebro-basilar accidents. In 2013, Thomas et al² found no alteration in blood flow in the brain with passive neck maneuvers used in cervical mobilization or before thrust of the cervical spine. 

Using Doppler ultrasonography, Erhardt et al conducted a randomized controlled trial examining the effects of high-velocity thrust (HVT) techniques, performed by a licensed physical therapist, of the atlantoaxial joint on hemodynamics of the suboccipital portion of the vertebral artery (VA3). 

Twenty-three healthy adult participants (14 men and 9 women; mean [SD] age, 40 [12.6] years [range, 27-69 years]) were randomly assigned to an intervention group (n=11), in which HVT was applied to the atlantoaxial segment, or a control group (n=12), in which participants were held in the premanipulative hold position. Doppler ultrasonography was used to measure VA3 hemodynamics. Exclusion criteria included a history of known vertebral artery anomalies, hypoplasia, various spinal conditions, and more. Participants were also excluded if the investigators were unable to visualize VA3 on ultrasonography. The primary outcome measures were peak systolic and end diastolic velocities, which were measured at neutral, pre-HVT, post-HVT, and post-HVT-neutral positions. 

Within-group comparison revealed no statistically significant differences between any cervical positions on peak systolic or end diastolic velocities for both the control and intervention groups, suggesting no statistically significant differences in blood flow velocity between HVT therapy and the static premanipulative hold position. Between-group comparison revealed no statistically significant changes between the control and intervention groups for any measurement variable, demonstrating no changes in blood flow velocity after HVT therapy. Because this study used only healthy patients, it remains uncertain as to how HVT therapy affects blood flow in diseased, inherently weak, or hypoplastic vessels. However, this article strengthens the research supporting cervical manipulation’s safety in healthy patients.