Reliability, construct and discriminative validity of clinical testing in subjects with and without chronic neck pain

Abstract
Background: The reliability of clinical tests for the cervical spine has not been adequately evaluated. Six cervical
clinical tests, which are low cost and easy to perform in clinical settings, were tested for intra- and inter-examiner
reliability, and two performance tests were assessed for test-retest reliability in people with and without chronic
neck pain. Moreover, construct and between-group discriminative validity of the tests were examined.
Methods: Twenty-one participants with chronic neck pain and 21 asymptomatic participants were included. Intra- and
inter-reliability were evaluated for the Cranio-Cervical Flexion Test (CCFT), Range of Movement (ROM), Joint Position
Error (JPE), Gaze Stability (GS), Smooth Pursuit Neck Torsion Test (SPNTT), and neuromuscular control of the Deep
Cervical Extensors (DCE). Test-retest reliability was assessed for Postural Control (SWAY) and Pressure Pain
Threshold (PPT) over tibialis anterior, infraspinatus and the C3-C4 segment.
Results: Intraclass Correlation Coefficient (ICC) for intra- and inter-examiner reliability was highest for ROM (range:
0.80 to 0.94), DCE (0.75 to 0.90) and CCFT (0.63 to 0.86). JPE had the lowest ICC (0.02 to 0.66). Intra- and inter-reliability
for GS and SPNTT showed kappa ranging from 0.66 to 0.92, and 0.57 to 0.78 (prevalence adjusted), respectively. For the
test-retest study, ICC was 0.83 to 0.89 for PPT and 0.39 to 0.79 for SWAY. Construct validity was satisfactory for all tests,
except JPE. Significant between group discriminative validity was found for CCFT, ROM, GS, SPNTT and PPT, however,
differences were within the limits of the minimal detectable change.
Conclusions: The majority of the tests evaluated showed satisfactory reliability and construct validity supporting their
use in the clinical evaluation of patients with chronic neck pain.
Keywords: Neck pain, Reliability, Validity assessment