What do Chiropractic and Yoga Have in Common? Potential Strokes Caused by Neck Injury
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So, do chiropractic manipulations and yoga exercises really have the potential to cause strokes?
Yes. The probability of it occurring might be fairly low, depending on individual susceptibility, but the increasing popularity of both practices, leading to the increased incidence of improper application, means there is an increased probability of incidence. In the case of chiropractic, estimates have varied from one in ten million manipulations to one in 40,000. 
The mechanism by which chiropractic and yoga can cause strokes almost entirely involves the neck, or cervical spine. So, if you avoid doing anything that involves those areas, you can probably reduce your stroke risk from yoga and chiropractic to almost nil.
What happens is, that a sudden and sharp manipulation of the cervical spine by a chiropractor, or an extremely high degree angle turn of the neck in a yoga inversion like a headstand, can cause a cervical arterial dissection leading to ischemic stroke.