Comparison of neck tension palpation rating systems with surface electromyographic and acoustic measures in vocal hyperfunction.

The purpose of this study was to evaluate current neck tension palpation rating systems to determine interrater reliability and possible correlation with necksurface electromyography (sEMG, collected from three electrode recording locations) and to measure the third formant for /a/ during various vocal behaviors. This prospective study examined the neck muscle tension of 16 participants before and after a single session of voice therapy. Interrater reliability and relationships between palpation ratings and objective measures of sEMG (anterior neck) and the third formant for /a/ were assessed using Pearson's correlations (r). Interrater reliability was relatively low as measured by Pearson's correlations, although Wilcoxon signed-rank test results were similar as those in a previous study. Correlations between palpation ratings and sEMG and between ratings of laryngeal height and the third formant for /a/ were generally low. Correlations increased between anterior neck sEMG and ratings of suprahyoid muscle tension when examined in a reduced set of individuals with higher interrater reliability. Palpation rating scales do not reliably capture changes that may occur in neck muscle tension of typical voice therapy patients over one session. Consequently, little can be concluded from correlations between sEMG and palpation ratings.