• Less dangerous than other types of manipulation
• More dangerous than other types of manipulation
• About the same risk as other types of manipulation

• About as dangerous as manipulations in other parts of the neck
• About twice as dangerous as manipulations in other parts of the neck
• About four x as dangerous as manipulations in other parts of the neck
• About ten x as dangerous as manipulations in other parts of the neck

• 38 years
• 48 years
• 55 years
• 68 years

• 1:10,000
• 1:50,000
• 1:500,000
• 1:1,000,000
• 1:3,000,000

• 1000 x more dangerous than taking NSAIDs over the same time for the same condition
• 100 x more dangerous than taking NSAIDs over the same time for the same condition
• About as dangerous as taking NSAIDs over the same time for the same condition
• 40 x less dangerous taking NSAIDs over the same time for the same condition

More dangerous. In a survey of Danish chiropractors, Klougart (J Manip Physiol Ther 19(6): 371-377) 1996) found one complication for every 1.3 million cervical treatment sessions, one for every 0.9 million upper cervical sessions and one in 400 thousand if rotation was used in the upper cervical spine. From this, rotational techniques in the upper spine are four times more likely to produce VBA than non-rotational. Rotation techniques in the lower spine were 2 almost 2.5 times more likely to produce VBA than non-rotational. The report all but recommended that rotational techniques should not be first choice in the upper spine.

About twice as dangerous (1.44) see above.

38 years. (Assendelft et al, J Family Pract 42(5):475-480 1996)

Depending on the source the reported incidence appears to be between 1:400,000 and never. The generally used figure is 1:1,000,000. The table below gives some of the estimates.

A review of the literature and comparisons to the use of NSAIDs for cervical pain (Dabbs, V. et al J Manual Physiol Therapeutics 18(8):530-536 1995) shows a very low risk of injury to the artery indeed much lower than the risk of taking NSAIDs for the same problem. Therefore estimated death rate per treatment is 0.00025% 160 times less frequent than the NSAIDs death rate. The estimated injury rate resulting in bleeding ulcers requiring hospitalization is 400 time less than the injury rate from manipulation. If ten treatments are used then manipulation is 16 times less likely to cause death and forty times less likely to cause injury than NSAIDs taken for the same condition. However, it can be argued that not all manipulation injuries are reported or even recognized for what they are while all hospitalized NSAIDs complications are, the comparison is not fair. Using a commonly accepted figure that 90% of medical accidents are unreported for spinal manipulation, then it is still 1.6 and 4 times safer than NSAID use for neck pain.