Effect of partial head extension swallowing exercise on the strength of the suprahyoid and tongue muscles in healthy subjects: A feasibility study

Abstract

Head extension swallowing exercise (HESE) is one of the exercise methods to strengthen the suprahyoid muscle and tongue. In this study, we modified the exercise protocol of the original HESE for application in patients who have difficulty in performing full HESE owing to decreased muscular strength related to swallowing. The purpose of this study was to investigate the feasibility and the effect of partial HESE on suprahyoid muscle activation and the tongue pressure during 30° extension of the head, rather than full extension, for 8weeks. Thirteen healthy young volunteers (mean age, 21.5±1.13years) participated in this study. The participants extended their head backward by 30° and swallowed their saliva every 10seconds. The exercise was performed three times a week for 8weeks. The effect of the exercise was confirmed by surface electromyography and tongue pressure measurement. The measurements were performed three times (baseline, at 4weeks and at 8weeks). No significant improvement in the tongue pressure-related parameters and suprahyoid muscle activation compared to those at baseline was observed as a result of the exercise. Although partial HESE in healthy adults did not lead to significant improvement in swallowing-related muscle strength, this study confirmed the feasibility of partial HESE. On the basis of these results, future studies should assess the applicability and effectiveness of partial HESE in elderly individuals and patients with dysphagia with swallowing-related muscular weakness.