Effects of Resistive Jaw-Opening Exercise with Elastic Resistance Bands on Suprahyoid Muscle Activation and Tongue Strength in the Elderly: A Pilot Study

Abstract

<b><i>Background:</i></b> The jaw-opening exercise (JOE) is designed to strengthen the suprahyoid muscles. However, it is difficult to apply this strength-training exercise to subjects in a systematic fashion. <b><i>Objective:</i></b> This study examined the effect of resistive JOE on suprahyoid muscle activity and tongue strength in the elderly through the use of an elastic band. <b><i>Methods:</i></b> Eight elderly people aged ≥65 years participated in this study. Participants wore an elastic loop around their head and mandible. The strength of the elastic loop used was adjusted based on the participant’s sex, and the same strength loop was used for 8 weeks. Participants were required to open their jaw maximally, maintain the position for 10 s, and then rest for 10 s. This process was repeated for 10 min. There was then a rest period of 2 min before subjects began another 10-min exercise set. All participants performed the exercise twice weekly for 8 weeks. All subjects were tested for suprahyoid muscle activation during typical/effortful swallowing as well as isometric tongue pressures and endurances at baseline and at 9 weeks. <b><i>Results:</i></b> After 8 weeks of exercise, the isometric maximum tongue-base pressure and tongue endurance were significantly improved. However, the swallowing tongue pressure and suprahyoid muscle activation levels had not changed significantly. <b><i>Conclusion:</i></b> This study confirmed that consistent resistance, which provides the same resistance throughout a resistive JOE exercise, is inadequate to reliably improve the muscle strength of swallowing-related muscles. Subsequent research should consider this and plan more efficient exercise programs.