In a study conducted in April of 2016 (Sze, Yoon, Escoffier, Rickard Liow), researchers evaluated the efficacy of the Chin Tuck Against Resistance (CTAR) and the Shaker exercise. Both exercises target the suprahyoid muscles, to facilitate the opening of the upper esophageal sphincter and improving bolus transfer.
The study used surface electromyography (sEMG) recordings from the suprahyoid muscles and the sternocleidomastoid muscle during the exercises, with 39 healthy adults.
The results indicated that the Chin Tuck Against Resistance (CTAR) exercise was more specific in targeting the suprahyoid muscles than the Shaker exercise and that the sternocleidomastoid muscles were significantly less activated and fatigued during the CTAR exercise than the Shaker exercise, which indicates that the CTAR exercise more effectively isolates and equally fatigues the suprahyoid muscles.
The suprahyoid muscles are located in the base of the tongue, under the chin and are involved in many key components of the swallow, including tongue base retraction, hyoid projection, laryngeal elevation, and upper esophageal sphincter opening. Therefore, exercises which target the suprahyoid muscles, such as the Chin Tuck Against Resistance (CTAR), can be helpful when treating many different types of swallow dysfunction.
The Chin Tuck Against Resistance (CTAR) exercise can be done using any flexible device (a ball, towel, etc.), held firmly under the chin to provide resistance to the motion of the chin pressing down against it as the head is nodded in a downward motion.
The ISO-PLUS Swallowing Exercise Device (swallowingexercises.com) was developed specifically for this exercise, as well as the Jaw Opening Against Resistance (JOAR) exercise, which also targets the suprahyoid muscles. This device flexes as pressure is applied, to allow for comfortable, smooth resistance throughout the full range of motion of the CTAR and JOAR exercises, to maximize isolation and fatigue of the suprahyoid muscles.
Evaluating the Training Effects of Two Swallowing Rehabilitation Therapies Using Surface Electromyography-Chin Tuck Against Resistance (CTAR) Exercise and the Shaker Exercise. Dysphagia. 2016 April;31(2):195-205. doi: 10.1007/a00455-015-9678-2. Epub 2016 Feb 2. Sze WP, Yoon WL, Escoffier N, Rickard Liow SJ.