The effects of two rehabilitation exercises on submental hyolaryngeal muscular activity

Abstract

This study compared the electrophysiological activity in hyolaryngeal muscles during performance of two exercises that target the submandibular laryngeal elevators. Twenty-six normal, healthy participants were measured using surface electromyography (sEMG) in three different conditions: (a) performing a baseline chin tuck with no resistance applied to the mandible, (b) performing the Chin Tuck Against Resistance Exercise (CTAR), and (c) performing the Chin-to-Chest Exercise (CtC). Measures of normalized sEMG peak amplitude and mean amplitude across 10 seconds of contraction were obtained. Results revealed a significant effect of condition on measures of peak and mean contraction amplitudes where both exercises were significantly greater than baseline chin tuck (p < 0.001 for both). Hyolaryngeal peak contraction amplitude and mean contraction amplitude were significantly greater during performance of the CtC compared to the CTAR exercise (p = 0.011 and 0.018, respectively). This study provides supporting evidence for the effect of two published exercises targeting submandibular muscles when compared to baseline. Both exercises incorporated resistance to facilitate an overload to muscle contraction, which likely accounted for baseline differences. The CtC exercise, which required jaw opening against a rigid brace, resulted in the greatest degree of neuromuscular activity in the submandibular muscles. Potential clinical implications will be discussed.