Two different analyzing methods for inhibitory reflexes: Do they yield comparable outcomes?

Background: For the analysis of inhibitory reflexes, no consensus exists regarding the methodology that should be used. The most commonly used methods are the cumulative sum (CUSUM) error box and the t-test. The aim of this study was to assess the interexaminer reliability of those two analyzing methods and to test whether both methods: yield similar results. Methods: Inhibitory jaw reflexes were recorded from the right masseter muscle of 11 participants (6 males, 5 females). Electrical stimuli were applied at the hairy skin of the upper lip on the right side. In total, 16 stimuli were applied while the participants maintained their clenching level at 10% of their maximum voluntary EMG activity. Two different examiners analyzed the reflex data with two different methods: the CUSUM error box and the t-test. The outcome variables were the number of reflex parts, the reflex area size, and the reflex onset. Comparability between examiners and between the two analyzing methods: was assessed with the use of the intraclass correlation coefficient (ICC). Results The interexaminer reliability was fair-to-good to excellent for both the CUSUM error box and the t-test analyses and for all the variables tested. The comparability of the two analyzing methods: was fair-to-good. Comparison with existing methods/conclusion When analyzing the inhibitory reflex data, both the CUSUM error box and the t-test can be used