Evaluating the Training Effects of Two Swallowing Rehabilitation Therapies Using Surface Electromyography—Chin Tuck Against Resistance (CTAR) Exercise and the Shaker Exercise

Abstract

In this study, the efficacy of two dysphagia interventions, the Chin Tuck against Resistance (CTAR) and Shaker exercises, were evaluated based on two principles in exercise science-muscle-specificity and training intensity. Both exercises were developed to strengthen the suprahyoid muscles, whose contractions facilitate the opening of the upper esophageal sphincter, thereby improving bolus transfer. Thirty-nine healthy adults performed two trials of both exercises in counter-balanced order. Surface electromyography (sEMG) recordings were simultaneously collected from suprahyoid muscle group and sternocleidomastoid muscle during the exercises. Converging results using sEMG amplitude analyses suggested that the CTAR was more specific in targeting the suprahyoid muscles than the Shaker exercise. Fatigue analyses on sEMG signals further indicated that the suprahyoid muscle group were equally or significantly fatigued (depending on metric), when participants carried out CTAR compared to the Shaker exercise. Importantly, unlike during Shaker exercise, the sternocleidomastoid muscles were significantly less activated and fatigued during CTAR. Lowering the chin against resistance is therefore sufficiently specific and intense to fatigue the suprahyoid muscles.

Efficacy of a novel swallowing exercise program for chronic dysphagia in long-term head and neck cancer survivors

“…By contrast, the amount of load in the Shaker exercise is not easily quantifiable, and cannot be manipulated progressively over the course of treatment . Moreover, the sternocleidomastoid muscles are probably significantly more activated and fatigued during the Shaker exercise than during the SEA exercises . As swallowing is a submaximal activity, whereby increase in muscle volume is not the focal point, for the current study, a resistive load of approximately 60%‐70% of the estimated 1RM was maintained as the resistance level.…”

“…32 Moreover, the sternocleidomastoid muscles are probably significantly more activated and fatigued during the Shaker exercise than during the SEA exercises. 42 As swallowing is a submaximal activity, 32 whereby increase in muscle volume is not the focal point, for the current study, a resistive load of approximately 60%-70% of the estimated 1RM was maintained as the resistance level. Besides, in this population of patients with head and neck cancer with chronic, severe dysphagia, hypertrophy is not expected.…”

Efficacy of modified chin tuck against resistance exercise using hand‐free device for dysphagia in stroke survivors: A randomised controlled trial

“…Compared with the control group, the experimental group showed a significant decrease in aspiration. Previous studies have demonstrated that CTAR exercise is an effective method to activate the suprahyoid muscles, using surface electromyography . The activation of more muscle fibres is likely to generate more power by recruiting more motor units.…”

Effects of game-based chin tuck against resistance exercise vs head-lift exercise in patients with dysphagia after stroke: An assessor-blind, randomized controlled trial

“…1), while sitting, in order to strengthen the same submental muscles as those targeted in the HLE; hence, the expected effect is similar to that of HLE. Sze et al (11) demonstrated that CTAR exercise is more efficient than HLE because it the activates submental muscles similar to or higher than the HLE. As a result, patients were able to perform the exercise more easily than HLE, and the drop-out rate, which was moderate, also decreased.…”