Before we had microwaves, we had ovens. Before we had cars, we had horses. And before we had CTAR, we had (and still have) the Shaker. As clinicians we’re always on the lookout for new or better interventions, so I wanted to look into a more recent article that gives an interesting perspective (from PTs!) that compares these and a novel approach to improve those stubborn suprahyoid muscles for better airway protection!
The article starts with a quick ‘n dirty history behind these 2 exercises )with some references to save for later😉), explaining how since “impaired laryngeal elevation is usually the underlying cause of inadequate airprotection” and “suprahyoid muscles are primarily reposnible for laryngeal elevation,” first came the Shaker.
Then, because of the difficulty and somewhat discomfort in implementing this horizontal exercise, Chin Tuck Against Resistance was discovered as an alternative.
Given the authors’ physical thinking brains, they were curious about if using a Theraband could also be a practical alternative for the same purpose🤔.
“Considering the advantages of theraband, we thought that we may perform resistance training of chin tuck exercise with theraband. Chin tuck exercise with theraband involves craniocervical flexion in isometric and isotonic forms which are performed with the resistance of theraband attached to the patient’s forehead with a fixed point at the back.” p.2
So they took their 36 HEALTHY participants (ages 18-40) who got randomly divided into the 3 intervention groups:
- CTAR group (n=12)
- Shaker group (n=12)
- Theraband group (n=12)
All subjects had to score less than 3 points on the Turkish EAT-10 for inclusion, and nobody could participate if they had a history of disk herniation, mechanical neck pain and/or pathology in the cervical region, any neurological/systemic disease, or history of surgery/radiotherapy treatment for heck/neck areas (for obvious reasons).
The authors give a pretty good detailed description for how, when, and what they measured:
Maximum Suprahyoid Muscle Activation (EMG)
Semirigid cervical neck orthosis was worn to the subjects”
“In order to measure maximum suprahyoid muscle activation, individuals were asked to perform opening their jaw maximum as hard as possible for 10 s against the cervical neck orthosis. Test was repeated 5 times with rest intervals of 60 s. The maximum value in five measurements was accepted for statistical analysis“
Anterior Tongue Pressure Force Measurement (IOPI)
Instructions to press the anteriorly placed bulb against palate as hard as possible for 5 seconds, repeated for 3 times with 2 minute rest intervals.
While I still need to do a bit more investigating since this is my first time coming across this term, a cervical auscultation device was included with the above EMG in order to, from what I gather, basically to see the total amount someone can tolerate to swallow at a time?🤨
Up to 30 ml water were given to all participants in various increments (starting at 1 ml) via syringe behind incisors and swallowing immediately following instructions.
“The maximum amount of water was accepted as dysphagia limit in which the symptoms of the test ending criteria were not observed.” p.3
While all the measurements were performed twice (before/after exercise program) by an experienced physical therapist who was blinded to the groups, another experienced physical therapist was in charge of actually teaching/training the programs to each group. Talk about our interdisciplinary collaborations guys!!
Each exercise program consisted of a set of isometric repetitions + isotonic exercise, which were all completed 30 min per day, 5 days a week (3 days with PT and 2 days home program with standardized brochure for each):
CTAR (with inflatable 12 cm diameter ball between chin/sternum):
- Compressed ball to maximum force for 60 sec; repeated 3 times with 60 sec rest intervals
- Compressive/relaxed ball 30 separate times
Shaker Exercises (lying supine position)
- Raise heads and look at toes for 60 sec; repeateed 3 times with 60 sec rest intervals
- Raise head 30 times to look at toes and slowly return to iniital supine position
Chin Tuck Exercise with Theraband:
- OMNI-RES EB )Perceived Exertion Scale for Resistance Exercise with Elastic Band) used to determine the level of resistance/color of band
- Sitting in 90′ upright position on chair; Theraband placed on forehead and fixed to the back
- Instructed NOT to open mouths and avoid head flexion during exercises
- Holding chin tuck position for 60 sec against theraband resistance; repeated 3 times with 60 sec rest intervals
- Chin tuck position against theraband resistance for 30 separate times
While I wish I could’ve seen some more photos of each step (head down/chin tucked vs head neutral with CTAR/Theraband etc.) because I’m a visual learner, I decided to include my own version of the last exercise group to help you guys imagine what this looks like:
Ok, so what did they find out with all these different contraptions, measurements, and positions?
Not only were there no differences in all the baseline measurements across all groups nor any differences in the descriptive info (age, gender, height/weight), but also “no difference in all groups before/after exercise” when it came to dysphagia limit. While the authors conclude this could likely be due to the syringe method bypassing oral and mucosal receptors for feedbackback, this should really be no surprise given the fact that we’re talking about HEALTHY ADULTS here. While we absolutely cannot conclude that these interventions will improve dysphagia impairment, I suppose at least you can say at least it doesn’t make it worse?🤷♀️
“In the current study, the CTAR and theraband group showed an increase in maximum suprahyoid muscle activation and tongue pressure, whereas there was no change in Shaker group.” p.5
Well let’s just say we should be happy that PTs were running this study to really help us understand more as to why:
“There are also studies showing that Shaker exercise increases muscle activation in superficial cervical flexor muscles rather than suprahyoid muscle. It has been reported that the Shaker exercise protocol leads to/cause muscular fatigue and the patient group is able to complete only average of 50% of isometric components of this protocol.”
“Shaker exercises are performed in supine position with lifting head against gravity. This positional difference creates various biomechanical changes.” p.5
“Although there was no difference in improvement of suprahyoid muscle activation between CTAR and theraband group, 39.5% increase was obtained in CTAR group and 13.1% increase in theraband group. We thought that the difference of 26.4% between two groups could be clinically significant.” p.6
The authors susggest having the tactile biofeedback input from the ball directly at the suprahyoid musculature could be an explanation, along with the more ‘inner range’ contracting position against the ball you’re already trying to hold with additional effort.
Before swiping all the Therabands you can find in the Rehab gym and making all the PT/OTs think you’ve really lost it, make sure to ponder more on the limitations first! Besides a small sample size, the authors admit that:
“Replication studies with patients with dysphagia would increase the understanding of the effect of exercises before clinical usage…It may be a limitation of this study that we did not evaluate the increase in laryngeal elevation.” p.7
So while no clear cut evidence (as usual), at least we know CTAR continues to be a clinically impactful exercise, and if this isn’t an option (especially for those trach patients!), possibly pulling out those colorful elastic bans might be an alternative!
Even more inspiring, go and talk to your PT friends now to get more input, feedback, and possibly data!!🤓
Kılınç, H., Arslan, S., Demir, N., & Karaduman, A. (2019). The Effects of Different Exercise Trainings on Suprahyoid Muscle Activation, Tongue Pressure Force and Dysphagia Limit in Healthy Subjects. Dysphagia, 35(4), 717-724. doi: 10.1007/s00455-019-10079-w
Some more resources on CTAR:
- Yoon, W., Khoo, J., & Rickard Liow, S. (2013). Chin Tuck Against Resistance (CTAR): New Method for Enhancing Suprahyoid Muscle Activity Using a Shaker-type Exercise. Dysphagia, 29(2), 243-248. doi: 10.1007/s00455-013-9502-9
- Sze, W., Yoon, W., Escoffier, N., & Rickard Liow, S. (2016). Evaluating the Training Effects of Two Swallowing Rehabilitation Therapies Using Surface Electromyography—Chin Tuck Against Resistance (CTAR) Exercise and the Shaker Exercise. Dysphagia, 31(2), 195-205. doi: 10.1007/s00455-015-9678-2
- Gao, J., & Zhang, H. (2017). Effects of chin tuck against resistance exercise versus Shaker exercise on dysphagia and psychological state after cerebral infarction. European Journal Of Physical And Rehabilitation Medicine, 53(3). doi: 10.23736/s1973-9087.16.04346-x
- Park, J., Lee, G., & Jung, Y. (2019). 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. Journal Of Rehabilitation Medicine, 51(10), 749-754. doi: 10.2340/16501977-2603