Inter-rater reliability determination for two tests of ulnar nerve conduction across the elbow.

INTRODUCTION: The inter-rater variability in determination of ulnar nerve conduction across the elbow compromises test accuracy. The extent of this variability is unknown. The objective of this study was to determine and compare inter-rater reliability of variables derived from 2 different ulnar nerve conduction studies (NCSs) across the elbow.

METHODS: Two investigators performed a standard ulnar NCS and a 6-cm conduction time (Six-Centimeter Conduction Time test, SCCT) on 60 extremities of asymptomatic subjects. In the standard test, below-elbow (BE) and above-elbow (AE) stimulation points were ≥ 10 cm apart, measured along a curved path, to calculate across-elbow NCV. In SCCT, BE and AE were precisely 6 cm apart measured linearly to calculate CTE (conduction time elbow). Inter-rater reliability was assessed by means of intraclass correlation coefficients (ICC).

RESULTS: ICC for across-elbow NCV and CTE were 0.726 and 0.801, respectively.

CONCLUSIONS: Reliability of CTE and across-elbow NCV are similar. Shorter distances, if measured linearly, can be used to determine across-elbow ulnar nerve conduction. Muscle Nerve 55: 664-668, 2017.