You have a 1 in 3.8 million chance of being killed by a shark....unless you're inland.

When spine is treated, the chance for injury is greatly increased the closer you get to the brainstem UNLESS the treatment/adjustment is ultra gentle and specific.

Older people, people with Osteoarthritis, Rheumatoid Arthritis, or Down's Syndrome should under no circumstances receive a high-velocity manipulation to the top of their neck.  I'll explain why...