Background.— Spinal manipulation (SM) is a therapy which is frequently used for headaches. During the last decade, several systematic reviews (SRs) of this topic have been published. Confusingly, their conclusions are far from uniform. The aim of this article is to identify the reasons for this confusion and to create more clarity about the therapeutic value of SM.
Methods.— SRs were identified through searches of Medline, Embase, Cochrane Library, Amed, Cinahl, and PsychInfo. They were considered if they were recent, systematic, and evaluated the effectiveness of SM for headache disorders.
Results.— Six SRs were included. Their methodological quality was assessed using the Oxman criteria for SRs. Five SRs were of high quality and one was associated with a high risk of bias. The findings of the SRs differed considerably. This variance seemed to be caused by several factors: differences in conditions included, treatments assessed, or primary studies analyzed.
Conclusion.— We conclude that high-quality SRs with a clear focus are required before the value of SM for headaches can be defined.