Within-Session and Between-Session Reliability, Construct Validity, and Comparison Between Individuals With and Without Neck Pain of Four Neck Muscle Tests

Abstract

BackgroundA variety of tests have been proposed to measure the performance of neck flexor muscles, but head-to-head comparisons hardly have been documented. ObjectiveTo compare reliability indexes, construct validity, and ability to discriminate between individuals with and without neck pain of 4 muscle tests (deep neck flexors endurance test [DNFET]; 2 variations of the craniocervical flexion test [CCFT1 and CCFT2]; and dynamometry). DesignReliability and validity study. SettingGeneral community. ParticipantsA total of 66 participants, 33 with chronic idiopathic neck pain (mean ± standard deviation pain intensity: 3.2 ± 1.9) and 33 without neck pain, from the general population. Methods/Main OutcomeNeck muscle functioning was assessed with the CCFT1, the CCFT2, the DNFET, and dynamometry on 2 separate sessions. Participants with neck pain also were assessed for pain intensity, disability, pain catastrophizing, and fear of movement. ResultsRelative reliability of all tests was at least moderate (intraclass correlation coefficient ≥ 0.62), whereas measurement error was high, particularly for the DNFET (95% minimum detectable change ≥ 23.00 seconds). All tests showed moderate correlation (r ≥ 0.3) with at least 2 pain-related measures and moderate-to-strong correlations with each other. Principal component analysis retained 2 factors explaining 68%-73% of the variance of the 4 muscle tests. Significant differences between groups were found for the DNFET and dynamometry (P < .05). ConclusionThe reliability indexes suggest that the DNFET and the CCFT may be more appropriate for group comparisons than for individual comparisons. The 4 tests seem to have construct validity, but they also seem to measure slightly different constructs. Level of EvidenceIII