Reliability of detecting 'onset of pain' and 'submaximal pain' during neural provocation testing of the upper quadrant.

BACKGROUND AND PURPOSE

Conflicting results have been reported with regard to the reliability of neural tissue provocation tests and it is unclear whether repeated testing affects the test results. In the present study, the stability and reliability of the occurrence of 'onset of pain' and 'submaximal pain' throughout the range of motion during neurodynamic testing was analysed, in both a laboratory and a clinical setting.

METHOD

A repeated-measures study design within and between sessions was used. In the laboratory and clinical settings, the base neurodynamic test for the median nerve was performed during a single session on a total of 27 patients with neurogenic cervico-brachial pain. In addition, the base test and three common variations were performed on two occasions by two examiners on 10 asymptomatic subjects in laboratory conditions only. Patients indicated the moment of 'submaximal pain' occurrence, whereas asymptomatic subjects indicated 'onset of pain' and 'submaximal pain'. Corresponding angles at the elbow were recorded by use of an electrogoniometer.

RESULTS

In the asymptomatic group, the intra- and inter-tester reliability within the same session was excellent (intraclass correlation coefficient (ICC2.1 > or = 0.95; standard error of measurement (SEM) < or = 4.9 degrees). Reliability after a 48-hour interval was moderate (ICC2.1 > or = 0.69; SEM < or = 9.9 degrees). The reliability coefficients for the symptomatic group within the same session were comparable with the excellent results of the asymptomatic group, for both the laboratory (ICC2.1 = 0.98; SEM = 2.8 degrees) and clinical settings (ICC2.1 > or = 0.98; SEM < or = 3.4 degrees). Consequently, from a statistical perspective, improvements in range of motion as small as approximately 7.5 degrees may be interpreted meaningfully. No significant trend due to repeated testing could be observed when three consecutive repetitions were analysed.

CONCLUSIONS

Pain provocation during neurodynamic testing is a stable phenomenon and the range of elbow extension corresponding with the moment of 'pain onset' and 'submaximal pain' may be measured reliably, both in laboratory and clinical conditions.