ObjectiveTo investigate the usefulness of ultrasonographic measurement of hyoid bone movement during swallowing.MethodsFifty-two patients who had swallowing dysfunction were enrolled in this study. When a patient swallowed 5 mL of water while maintaining an upright sitting position, hyoid bone movement during swallowing was measured with ultrasonography. Recorded images were analyzed to measure the maximum change in hyoid bone displacement. Mandible was used as reference point to calculate hyoid bone displacement. The farthest distance from resting position and the nearest distance during swallowing were measured and their differences were recorded. Participants also underwent videofluoroscopic swallowing study (VFSS). Based on penetration-aspiration scale (PAS), they were grouped to non-aspirators (PAS 1), penetrators (PAS 2–5), or aspirators (PAS 6–8). Measured hyoid bone displacements by submental ultrasonography were compared among groups.ResultsThe mean hyoid bone displacement in non-aspirators group (n=21, 15.9±2.7 mm) was significantly (p<0.05) greater than that in penetrators group (n=20, 11.5±2.8 mm) or aspirators group (n=11, 8.0±1.0 mm). Hyoid bone displacement below 13.5 mm as a cutoff point for detecting penetration or aspiration had a sensitivity and specificity of 83.9% and 81.0%, respectively.ConclusionSubmental ultrasonographic evaluation was well correlated with PAS measured by VFSS. Therefore, submental ultrasonographic evaluation could be a useful screening tool for dysphagic patients.

Posturographic examination is commonly used by clinicians to evaluate standing balance. Because it is perfomed with double leg standing, it cannot sensitively detect the minor balance problem like functional ankle instability. This study aims to evaluate the test retest reliability of the single leg balance test using Tetrax posturography and its correlation with modified star excursion balance test (mSEBT). 30 healthy participants (16 male, 14 female, mean age 26.3±3.3) were volunteered for this study. We manufactured a specially designed wood plate to assess their single leg standing balance. It was set on each of the 4 force plates of Tetrax posturography (Sunlight Medical Ltd., Ramat Gan, Israel). Stability index were measured based on each single leg stance. Participants performed the single leg balance test on Tetrax posturography in three different times, and they also performed the mSEBT. The test retest reliability of stability index measured by Tetrax posturography was assessed by the intraclass correlation coefficient, and its correlation with the normalized composite distance of mSEBT was assessed by Pearson correlation coefficient. The single leg balance test using Tetrax posturography showed good test retest reliability. There was a negative correlation between the stability index of Tetrax posturography and the normalized composite distance of mSEBT, based on right and left leg stance, respectively. These findings suggest that Tetrax posturography is a useful and reliable tool for single leg balance assessment.