Measurement Properties of the Craniocervical Flexion Test: A Systematic Review

Patients with neck pain commonly have altered activity of the neck muscles. The craniocervical flexion test (CCFT) is used to assess the function of the deep neck flexor muscles in patients with musculoskeletal neck disorders. Systematic reviews summarizing the measurement properties of the CCFT are outdated. The objective of this study was to systematically review the measurement properties of the CCFT for assessing the deep neck flexor muscles.

The data sources MEDLINE, EMBASE, Physiotherapy Evidence Database, Cochrane Central Register of Controlled Trials, Scopus, and Science Direct were searched in April 2019. Studies of any design that reported at least 1 measurement property of the CCFT for assessing the deep neck flexor muscles were selected. Two reviewers independently extracted data and rated the risk of bias of individual studies using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) risk-of-bias checklist. The overall rating for each measurement property was classified as "positive," "indeterminate," or "negative." The overall rating was accompanied with a level of evidence.

Fourteen studies were included in the data synthesis. The ratings were positive, and the level of evidence was moderate for interrater and intrarater reliability and convergent validity. There was conflicting rating and level of evidence for discriminative validity. Measurement error was indeterminate, with an unknown level of evidence. Responsiveness was negative, with a limited level of evidence. A limitation of this study was that only papers published in English were included.

The CCFT is a valid and reliable test that can be used in clinical practice as an assessment test. Because of the conflicting and low-quality evidence, caution is advised when using the CCFT as a discriminative test and as an outcome measure. Future better-designed studies are warranted.