Reliability of Upper Limb Neurodynamic Tests: Median, Radial, and Ulnar Nerves

Objective Upper limb neurodynamic tests are used to evaluate the mechanical sensitivity of the peripheral nerves. However, very little is known about the reliability of upper limb neurodynamic tests, especially for the radial and ulnar nerves. This study aimed to evaluate the reliability of neurodynamic tests of the upper extremities to test median, radial, and ulnar nerves. Materials & Methods In this observational cross-sectional study, 25 asymptomatic subjects aged 19-45 years participated. They were selected using simple non-random sampling. Then two examiners performed the neurodynamic tests on them on two successive days. The goal was to assess the reliability of median, radial, and ulnar neurodynamic tests. During the neurodynamic tests, the participants reported the initial stretching pain and the moment of submaximal pain (substantially obvious pain) in related areas of the nerve distribution, including the anterior side of the elbow and forearm for the median nerve, posterolateral aspect of the elbow and forearm for radial nerve, and medial side of elbow and forearm for the ulnar nerve. At the starting point of painful stretching and the submaximal pain, the angle of elbow extension (for median and radial nerve tests) and shoulder abduction angle (for ulnar nerve test) were measured using a mechanical goniometer. The range between these two points was used to analyze the reliability. The intraclass correlation coefficient (ICC) and the standard error of measurement (SEM) were calculated to examine the relative and absolute reliability, respectively. Using t-test, the difference in the mean of the measurements was calculated. Results No significant difference was found between the mean measurements of the two testers in intra-session and inter-session reliability. For examiners 1 and 2, was obtained 0.94 (SEM:2ο) and 0.89 (SEM:2.85ο) for the median nerve, 0.56 (SEM:6.36˚ ) and 0.93 (SEM:1.82ο) for radial nerve, and 0.42 (SEM:3.27ο) and 0.79 (SEM:1.42ο) for the ulnar nerve. Inter-tester intra-session reliability was obtained at 0.84 (SEM: 3.44ο), 0.54 (SEM: 6.1ο), and 0.55 (SEM: 2.75ο), respectively, for median, radial, and ulnar nerves. Inter-tester inter-session reliability was obtained at 0.97 (SEM:1.43ο), 0.69 (SEM:5.06ο), and 0.51 (SEM: 2.8˚ο), respectively, for median, radial, and ulnar nerves. Conclusion The upper limb neurodynamic tests and measurement of the range between the onset of stretching pain and the point of submaximal pain have moderate to excellent reliability. Therefore, these clinical tests can be used in diagnostic evaluations and treatment interventions. Also, the median nerve neurodynamic test has higher relative reliability than radial and ulnar nerve neurodynamic tests.