Pre-manipulative testing and the use of the velocimeter.

Manipulation of the cervical spine remains a common intervention for neck pain and dysfunction, despite the well-documented associated risk of vertebrobasilar stroke. The currently advocated pre-manipulative risk assessment protocols include the use of provocative positional tests to challenge the integrity of the vascular supply to the brain. This paper critically evaluates the validity of these pre-manipulative provocative tests in the light of ultrasonographic blood flow studies of the vertebral arteries. It also critically evaluates the evidence concerning the clinical utility of a portable continuous wave Doppler device (or velocimeter) to examine vertebral artery blood flow prior to neck manipulation. There is clear evidence that the provocative tests may produce both false positive and false negative findings. Initial research regarding the clinical use of a velocimeter suggests this device may provide a more objective assessment of vertebral artery blood flow than the provocative tests. However, the sensitivity, specificity and reliability of the use of the velocimeter in identifying abnormal vascular flow in the vertebral arteries, and therefore its clinical utility, has not yet been fully established.