Intra- and inter-examiner variability in performing Tinel's test

The Tinel sign was adopted in the early 1950s to detect sites of nerve compression. There have been few attempts to standardize how one elicits Tinel's sign. The goal of this study was to evaluate intra- and inter-examiner variability in the force generated using different techniques to elicit Tinel's sign.

Nine clinicians, consisting of 3 experienced hand and peripheral nerve surgeons, 3 junior hand and peripheral nerve surgeons, and 3 surgeons in training were included in the study. Three different Tinel-type maneuvers were evaluated: (1) striking the load cell using the dominant middle finger only ("single-finger strike"), (2) using the dominant index and middle finger together ("double-finger strike"), and (3) preloading with the nondominant thumb and then striking the thumb with the dominant middle finger ("preload"). Test subjects were instructed to use their customary range of force during the testing. Each subject performed 3 sets of 5 strikes per technique.

There was a significant difference in nearly all subjects between the range of force generated with single- or double-finger techniques and preload technique. There was also a difference in nearly all subjects when comparing the range of forces using the single-and double-finger techniques. In addition, there were large differences in the range of forces produced by the examiners for each technique.

There is no standardization for eliciting the Tinel sign. This study demonstrates considerable intra- and inter-examiner differences in the range of forces generated by the different Tinel's techniques that are used in clinical practice. This variability might explain clinical differences between examiners in the ability to obtain a Tinel sign in a patient and might explain the inconsistency of sensitivity and specificity reported for Tinel's sign. Further research on standardization is needed, and future study protocols using Tinel's sign should take these findings into account.