This systematic review with meta-analysis of randomized clinical trials (RCTs) estimated the benefits and harms of cervical spinal manipulative therapy (SMT) for treating neck pain. The authors searched the MEDLINE, Cochrane CENTRAL, EMBASE, CINAHL, PEDro, Chiropractic Literature Index bibliographic databases, and grey literature sources, up to June 6, 2022.
RCTs evaluating SMT compared to guideline-recommended and non-recommended interventions, sham SMT, and no intervention for adults with neck pain were eligible. Pre-specified outcomes included pain, range of motion, disability, health-related quality of life.
A total of 28 RCTs could be included. There was very low to low certainty evidence that SMT was more effective than recommended interventions for improving pain at short-term (standardized mean difference [SMD] 0.66; confidence interval [CI] 0.35 to 0.97) and long-term (SMD 0.73; CI 0.31 to 1.16), and for reducing disability at short-term (SMD 0.95; CI 0.48 to 1.42) and long-term (SMD 0.65; CI 0.23 to 1.06). Only transient side effects were found (e.g., muscle soreness).
The authors concluded that there was very low certainty evidence supporting cervical SMT as an intervention to reduce pain and improve disability in people with neck pain.
Harms cannot be adequately investigated on the basis of RCT data. Firstly, because much larger sample sizes would be required for this purpose. Secondly, RCTs of spinal manipulation very often omit reporting adverse effects (as discussed repeatedly on this bolg). If we extend our searches beyond RCTs, we find many cases of serious harm caused by neck manipulations (also as discussed repeatedly on this bolg). Therefore, the conclusion of this review should be corrected: