Chin Tuck Against Resistance (CTAR)
CTAR is a strength-based exercise intended to strengthen the perihyoid muscles. This tutorial will take you through the steps for prescribing and instructing the CTAR exercise.
First, before recommending CTAR for a patient, it is important to determine if a person's perihyoid strength is weak. If a patient's perihyoid strength is within normal limits, then you may consider recommending exerices other than CTAR. If perihyoid strength is reduced (weak), then targeting increased perihyoid strength via CTAR may be a helpful treatment target (although there may be other more effective exercises). How do you measure perihyoid strength clinically? Use the Open Mouth-Maximal Isometric Press (OMMIP)!
The OM-MIP is a simple, objective way to quantify perihyoid strength. OM-MIP involves having a person tuck their chin with maximal force against a handheld dynamometer while maintaining a neutral open mouth posture. The OMMIP has age- and sex-based norms to objectively determine if a person's perihyoid strength is within or outside of normal limits.
By assessing your patient’s OMMIP, you can: (1) objectively determine if perihyoid strength is reduced; (2) systematically decide whether CTAR is appropriate; and (3) individualize the intensity of the CTAR exercise to fit your patient’s strength training needs.
Second, determine which device will be used to facilitate CTAR. Cushion balls were used in the original CTAR publication (see below image) and are therefore frequently used for CTAR. However, the resistance exerted by a cushion ball can vary greatly based on the location and depth of each CTAR compression (see below video). This can drastically affect treatment delivery and rehabilitation outcomes!
Therefore, consider using the Neckline Slimmer (Note: I have no financial conflict of interest). The Neckslimmer allows the clinician and patient to clearly determine when a CTAR repetition was completed accurately or not. This allows for easier and more accurate delivery of the CTAR exercise for your patient. The NecklineSlimmer comes with 3 different resistance springs which can be used in isolation or combination, for a total of 7 resistance levels. This allows for the possibility of much more targeted, patient-specific, strength training regimen.
Lastly, determine the intensity level and dose of the CTAR exercise. To do this, place the CTAR device onto the dynamometer. Then, press the device until one full compression is complete and read the value on the dynamometer. Then, compare this value, to the patient's OMMIP. For a low intensity CTAR, practice each repetition at ~50-60% of the patient's OMMIP. For moderate intensity, practice at ~60-80% of the patient's OM-MIP, and for high intensity, practice at ~80-100% of the patient's OM-MIP.
If doing moderate-to-high intensity strength training, consider 2-3 seconds per rep, 2-3 seconds rest between each rep, 10-12 reps/set, 3-4 sets/session, 2-3 minutes break between each set, 3-4 days/week. If working on low intensity endurance training, consider 60 seconds per rep, 1 rep/set, 3-5 sets/session.
Make sure to re-evaluate OM-MIP every week and adjust the intensity of CTAR in order to maintain the desired intensity level! In the video below, a patient's OM-MIP was measured at 12 kilograms of force (kgf) - which is >2 standard deviations below the mean for this person's age and sex. Since the I was recommending practicing at 80% of the patients OM-MIP, I used the dynamometer to determine which springs were needed to obtain 10 kgf for one CTAR repetition.
References
Yoon, W. L., Khoo, J. K. P., & Rickard Liow, S. J. (2014). Chin tuck against resistance (CTAR): new method for enhancing suprahyoid muscle activity using a Shaker-type exercise. Dysphagia, 29(2), 243-248.
Park, J. S., & Hwang, N. K. (2021). Chin tuck against resistance exercise for dysphagia rehabilitation: a systematic review. Journal of oral rehabilitation, 48(8), 968-977.
Curtis, J. A., Langenstein, J., Troche, M. S., Laus, J., & Schneider, S. L. (2019). Open mouth-maximal isometric press: Development and norms for clinical swallowing evaluations and treatment. American journal of speech-language pathology, 28(1), 148-154.