|
|
 |
Chiropractic Safety Research
|
Passive Care:
Adjustments - Safety (Stroke)
|
|
*Symons, B et al. Internal forces sustained by the vertebral artery during spinal manipulative therapy. J Manipulative Physiol Ther. 2002 Oct; 25(8):504-10.
Adjustments have been shown to be effective for the management of several disorders of the muscular and skeletal system.
An issue which receives an abundance of attention, especially in the popular press is the safety of neck adjustments and the risk of stroke.
The objective of this study was to calculate the forces applied to the vertebral artery with Adjustments and then to compare those forces to the minimum force required to damage the vertebral artery.
- Adjustments to the neck resulted in an average strain of 2.1% - 6.2% of the vertebral artery.
(The percent strain is another way of saying the percentage of length change from its normal resting length; so 2.1% strain means that the vertebral artery was stretched 2.1% of its total length with an Adjustment.) These values were similar to or lower than the strains recorded during diagnostic and range of motion testing.
- This study revealed that the vertebral arteries could be stretched to 139% to 162% of their resting length before damage occurred.
CONCLUSIONS:
Adjustments resulted in strains to the vertebral arteries that were almost 10 times lower than the strains required to damage it.
This study concludes that under normal circumstances, a single Adjustment is very unlikely to damage the vertebral artery.
*This was a cadaveric study involving six unembalmed postrigor cadavers.
|
|
|
|
