Let’s look at the evidence for the claims I made earlier. These are thorough and systematic reviews that take into account the quality of the studies, since poor quality studies can be made to look like they support anything. They are also far more current than the studies you refer to, several of which were done in the 1970s and have been superseded.
1. Subluxation theory is bogus:
Mirtz TA, Morgan L, Wyatt LH, Greene L. An epidemiological examination of the subluxation construct using Hill’s criteria of causation. Chiropractic & Osteopathy 2009, 17:13, 2009.
:There is a significant lack of evidence in the literature to fulfill Hill’s criteria of causation as regards chiropractic subluxation. No supportive evidence is found for the chiropractic subluxation being associated with any disease process or of creating suboptimal health conditions requiring intervention. Regardless of popular appeal this leaves the subluxation construct in the realm of unsupported speculation. This lack of supportive evidence suggests the subluxation construct has no valid clinical applicability.”
2. Chiro may have minimal beneficial impact on back pain but no proven benefits for anything else.
Ernst E, Carter PH. A systematic review of systematic reviews of spinal manipulation. J R Soc Med 99:192,196, 2006.
“Collectively these data do not demonstrate that spinal manipulation is an effective intervention for any condition. Given the possibility of adverse effects, this review does not suggest that spinal manipulation is a recommendable treatment. “
Rubinstein SM, Terwee CB, Assendelft WJJ, de Boer MR, van Tulder MW. Spinal manipulative therapy for acute low-back pain. Cochrane Database of Systematic Reviews 2012, Issue 9. Art. No.: CD008880.
“High quality evidence suggests that there is no clinically relevant difference between SMT and other interventions for reducing pain and improving function in patients with chronic low-back pain.”
Bronfort G, Haas M, Evans R, Leininger B, Triano J. Effectiveness of manual therapies: the UK evidence report. Chiropr Osteopat. 2010; 18: 3.
“Spinal manipulation/mobilization is effective in adults for acute, subacute, and chronic low back pain; for migraine and cervicogenic headache; cervicogenic dizziness; and a number of upper and lower extremity joint conditions. Thoracic spinal manipulation/mobilization is effective for acute/subacute neck pain, and, when combined with exercise, cervical spinal/manipulation is effective for acute whiplash-associated disorders and for chronic neck pain. The evidence is inconclusive for cervical manipulation/mobilization alone for neck pain of any duration, and for any type of manipulation/mobilization for mid back pain, sciatica, tension-type headache, coccydynia, temporomandibular joint disorders, fibromyalgia, premenstrual syndrome, and pneumonia in older adults. Spinal manipulation is not effective for asthma and dysmenorrhea when compared to sham manipulation, or for Stage 1 hypertension when added to an antihypertensive diet. For children, the evidence is inconclusive regarding the effectiveness of spinal manipulation/mobilization for otitis media and enuresis, but shows it is not effective for infantile colic and for improving lung function in asthma when compared to sham manipulation.
The evidence regarding massage shows that for adults it is an effective treatment option for chronic LBP and chronic neck pain. The evidence is inconclusive for knee osteoarthritis, fibromyalgia, myofascial pain syndrome, migraine headache, and premenstrual syndrome. For children, the evidence is inconclusive for asthma and infantile colic.
Why is it that the results of RCTs often do not confirm the results observed in clinical practice? There are several reasons. One of the problems is that both the provider and the patient are likely to interpret any improvement as being solely a result of the intervention being provided. However this is seldom the case. First, the natural history of the disorder (for example. acute LBP) is expected to partially or completely resolve by itself regardless of treatment. Second, the phenomenon of regression to the mean often accounts for some of the observed improvement in the condition.
Additionally, there is substantial evidence to show that the ritual of the patient practitioner interaction has a therapeutic effect in itself separate from any specific effects of the treatment applied.”
Cherkin DC, Deyo RA, Battie M, Street J, Barlow W. A comparison of physical therapy, chiropractic manipulation, and provision of an educationsl booklet for the treatment of patients with low back pain. NEJM, 339:Vol 15:1021-1029, 1998.
Summary: “For patients with low back pain, the McKenzie method of physical therapy and chiropractic manipulation had similareffects and costs, and patients receiving these treatments hadonly marginally better outcomes than those receiving the minimalintervention of an educational booklet. Whether the limited benefits of these treatments are worth the additional costs is open to question.”
Given the minimal chance of benefits, the real possibility of harm has to be weighed as well:
Gouveia LO, Castanho P, Ferreira JJ. Safety of chiropractic interventions: a systematic review. Spine 34(11) E405-13. 2009.
“The frequency of adverse events varied between 33% and 60.9%, and the frequency of serious adverse events varied between 5 strokes/100,000 manipulations to 1.46 serious adverse events/10,000,000 manipulations and 2.68 deaths/10,000,000 manipulations.”
Rothwell, DM, Bondy SJ, Williams JI. Chiropractic manipulation and stroke: A Population-based case-control study. Stroke 32:1054, 2001.
Summary: Patients with a vertebrobasilar artery stroke who were under the age of 45 were 5 times as likely as controls to have visited a chiropractor during the week preceding their stroke.