"Systematic reviews of controlled clinical studies of treatments used by chiropractors have found no evidence that chiropractic manipulation is effective, with the possible exception of treatment for back pain.[8] A 2011 critical evaluation of 45 systematic reviews concluded that the data included in the study "fail[ed] to demonstrate convincingly that spinal manipulation is an effective intervention for any condition."[10] Spinal manipulation may be cost-effective for sub-acute or chronic low back pain, but the results for acute low back pain were insufficient.[11] No compelling evidence exists to indicate that maintenance chiropractic care adequately prevents symptoms or diseases.[12]"
Worked for my ex-wife. 6 treatments and he sent her home, fixed for good. The bad stories may outweigh the good, but let's not pretend all practitioners are dumbasses.
For people who point to certifications and education, I'll remind them that plenty of doctors and nurses smoke and are anti-vax. It ain't a perfect world.
They are not practitioners. They hold no medical degree and you should not trust them with any medical care. Treat them for what they are, glorified back crackers who peddle pseudoscience and may kill you by accident.