Changes in Vertebral Arterial Blood Flow During Premanipulative Tests in Participants With Upper Cervical Spine Motion Restriction

Objective: The purpose of the present study was to measure changes in blood flow velocity and volume flow rate (VFR) in the contralateral vertebral artery (VA) during end-range rotation and pre-manipulative hold at C1-C2 and to compare these measurements between participants with and without C1-C2 range of motion (ROM) restriction. Methods: This research was approached as an exploratory study and designed as a parallel noninterventional controlled trial with intentionally equal allocation, for studying diagnostic tests. Fifteen women and 13 men (mean age 44) were recruited (volunteer sample) in physiotherapy clinics. No participant had any current neurologic or vertebrobasilar insufficiency symptoms. The measurements of 13 participants with a limited ROM C1-C2 and 15 with no limitation were compared. Blood flow velocity and VFR in the contralateral VA were measured using color duplex Doppler imaging in 3 neck positions: neutral, maximal rotation, and pre-manipulative hold of C1-C2. Results: Pre-manipulative hold significantly (P <.01) decreased all blood flow velocity parameters and VFR, mainly in the left VA. End-range rotation showed a significant (P <.05) decrease in the peak systolic velocity in the left VA. No significant differences were found between participants grouped by the presence or absence of a C1-C2 ROM restriction. Conclusion: A C1-C2 rotational ROM restriction does not appear associated with change in a significantly reduced VA blood flow due to the neck position.