Methodological quality and outcomes of studies addressing manual cervical spine examinations: a review

The aims of this review were, first to rate the methodological quality of studies which investigate the reliability of manual tests for cervical spine dysfunctions by applying a new quality assessment tool; secondly to compare the outcomes of these studies. The literature search included databases of CINAHL, MEDLINE, AMED, AMI, and SPORT DISCUS, the Cochrane Library, the Physiotherapy Evidence Database (PEDro), the National Library of Medicine (PubMed), Factiva, the EBSCOT HOST Research Database, online journal databases of ELSEVIER Science periodicals, LIPPINCOTT WILLIAMS & WILKINS, ELSEVIER Science @ Direct, THIEME ONLINE, and BLACKWELL SYNERGY. The application of the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS) to the 15 studies which met the inclusion criteria showed methodological weaknesses such as not considering an independent reference standard, or a representative study population. The studies demonstrated methodological strength in describing selection criteria and in interpreting results. The studies' outcomes make the claim to be able to detect segmental cervical dysfunction based on a manual assessment only questionable. Further improvements in quality, uniform study designs, and a valid reference standard would be necessary in order to obtain more reliable data in the future.