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A Pilot Study of the Tongue Pull-Back Exercise for Improving Tongue-Base Retraction and Two Novel Methods to Add Resistance to the Tongue Pull-Back

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Laurie Slovarp at University of Montana
Laurie Slovarp
Lauren King
Lauren King
Lauren King
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Catherine A Off at University of Montana
Catherine A Off
Julie M Liss at Arizona State University
Julie M Liss
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Abstract and Figures

This pilot study investigated the tongue pull-back (TPB) exercise to improve tongue-base retraction as well as two methods to add resistance to the TPB. Surface electromyography (sEMG) to the submental triangle was used as an indication of tongue-base activity on 13 healthy adults during: (1) saliva swallow, (2) 15 mL water swallow, (3) effortful swallow, (4) unassisted TPB, (5) TPB with added resistance by holding the tongue with gauze (finger-resisted TPB), and (6) TPB with the tongue clipped to a spring-loaded tension resistance device (device-resisted TPB). Order of the exercises was randomized. The exercises fell into two groups-weak and intense. Weak exercises included saliva swallow, water swallow, and unassisted TPB (mean sEMG = 19.07 μV, p = .593). Intense exercises included effortful swallow, finger-resisted TPB, and device-resisted TPB (mean sEMG = 36.44 μV, p = .315). Each intense exercise resulted in significantly higher mean sEMG peak amplitude than each weak exercise (p < .05), with one exception; the effortful swallow was not significantly different than the unassisted TPB (p = .171). This study provides preliminary evidence that the unassisted TPB may not be any more helpful for improving tongue-base retraction than normal swallowing. Adding resistance to the TPB by holding the tongue with gauze may be an effective alternative. This study also demonstrates proof-of-concept for creating a device to attach to the tongue and provide tension resistance during the TPB exercise. Further research with a more sophisticated design is needed before such a device can be fully developed and implemented clinically.
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ORIGINAL ARTICLE
A Pilot Study of the Tongue Pull-Back Exercise for Improving
Tongue-Base Retraction and Two Novel Methods to Add
Resistance to the Tongue Pull-Back
Laurie Slovarp
1
•Lauren King
1
•Catherine Off
1
•Julie Liss
2
Received: 25 June 2015 / Accepted: 20 January 2016 / Published online: 9 February 2016
ÓSpringer Science+Business Media New York 2016
Abstract This pilot study investigated the tongue pull-
back (TPB) exercise to improve tongue-base retraction as
well as two methods to add resistance to the TPB. Surface
electromyography (sEMG) to the submental triangle was
used as an indication of tongue-base activity on 13 healthy
adults during: (1) saliva swallow, (2) 15 mL water swal-
low, (3) effortful swallow, (4) unassisted TPB, (5) TPB
with added resistance by holding the tongue with gauze
(finger-resisted TPB), and (6) TPB with the tongue clipped
to a spring-loaded tension resistance device (device-re-
sisted TPB). Order of the exercises was randomized. The
exercises fell into two groups—weak and intense.Weak
exercises included saliva swallow, water swallow, and
unassisted TPB (mean sEMG =19.07 lV, p=.593). In-
tense exercises included effortful swallow, finger-resisted
TPB, and device-resisted TPB (mean sEMG =36.44 lV,
p=.315). Each intense exercise resulted in significantly
higher mean sEMG peak amplitude than each weak exer-
cise (p\.05), with one exception; the effortful swallow
was not significantly different than the unassisted TPB
(p=.171). This study provides preliminary evidence that
the unassisted TPB may not be any more helpful for
improving tongue-base retraction than normal swallowing.
Adding resistance to the TPB by holding the tongue with
gauze may be an effective alternative. This study also
demonstrates proof-of-concept for creating a device to
attach to the tongue and provide tension resistance during
the TPB exercise. Further research with a more sophisti-
cated design is needed before such a device can be fully
developed and implemented clinically.
Keywords Deglutition Deglutition disorders
Dysphagia Tongue-base retraction Electromyography
Effortful swallow Tongue pull-back Strength training
The pharyngeal swallow consists of a series of multiple
complex sensory-motor events that occur in a coordinated
fashion to efficiently and effectively move a bolus through
the pharynx and into the esophagus, while simultaneously
protecting the airway from aspiration [1,2]. Motor events
that contribute to the pharyngeal swallow include tongue-
base retraction, hyolaryngeal elevation and excursion,
sequential contraction of the pharyngeal constrictors, and
opening of the upper esophageal sphincter (UES) [1–4].
The role of tongue-base retraction during the swallow is to
move the base of the tongue posteriorly to meet the pos-
terior pharyngeal wall, which moves superiorly and ante-
riorly during the swallow [1,3–6]. Collectively, posterior
movement of the tongue base and superior-anterior
movement of the posterior pharyngeal wall increase pha-
ryngeal pressure during the swallow to push the bolus
through the pharynx and into the esophagus [3,5,7].
Impairment in tongue-base retraction results in post-swal-
low residue within the pharynx, particularly the valleculae,
and is common in patients suffering from dysphagia due to
various etiologies [2,8–11].
The literature is inconsistent regarding the exact muscles
responsible for tongue-base retraction. Most sources describe
the intrinsic and extrinsic lingual muscles when discussing
anatomy but then generally refer to the ‘‘tongue base’’ or
&Laurie Slovarp
laurie.slovarp@umontana.edu
1
Communicative Sciences and Disorders, The University of
Montana, 32 Campus Drive, Missoula, MT 59812-9968, USA
2
Speech and Hearing Science, Arizona State University, 975
S. Myrtle Ave, P.O. Box 870102, Tempe, AZ 85287-0102,
USA
123
Dysphagia (2016) 31:416–423
DOI 10.1007/s00455-016-9693-y
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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... The researchers noted the limitations of ES as an exercise program. Slovarp et al. reported that the suprahyoid muscle activation level varied significantly among people during ES performance [3]. This indicates that the performance level may be inconsistent in patients with dysphagia performing ES. ...
... They also pointed out limitations in terms of resistive load and gradual resistance provision. In addition, ES is difficult to be performed by patients with severe dysphagia because it requires repeated swallowing by participants for exercise [3]. According to Kim et al., ES exercise is limited in that exercise intensity cannot be quantified [9]. ...
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View
... When introducing a new rehabilitative exercise, establishing its effects on healthy subjects is an important first step before applying it to patient populations [4]. Generally, pilot studies of newly developed rehabilitative exercises verify the physiological effects of these exercises on healthy individuals using sEMG [4,11,12]. ...
... These pressures may provide additional information about the therapeutic mechanism underlying training effects. Both the measurements used in this study have been used in previous studies to represent the changes generated during long-term swallowing-related exercises in healthy subjects [4,11,18]. This study hypothesized that long-term HESE would enhance swallowing-related submental muscle activation and tongue pressure. ...
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... However, in the case of muscle strengthening exercises, when the primary cause of a swallowing disorder is muscle weakness or muscle tension, various exercise methods comprising tasks that induce higher loading than the level of muscle activity required for typical swallowing may be used [5,8,9]. Nevertheless, it is difficult to objectively and systematically monitor and control the resistance applied to the swallowing muscles when performing skill-based or strength training to improve swallowing function [5,10,11]. ...
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The suprahyoid muscles play an important role in protecting the airway by elevating both the hyoid bone and larynx superior-anteriorly during swallowing. However, providing systematic external resistance when performing exercises to improve suprahyoid muscle strength is practically difficult. This study attempted to confirm whether systematic resistance can be provided to the suprahyoid muscles using the Iowa Oral Performance Instrument (IOPI)—a representative tongue pressure measurement device. Thirty-one healthy adults participated in this study (20.6 ± 0.96 y, 19 females). The participants performed 16 exercise tasks using the IOPI three times each in random order (Anterior/posterior tongue × pressing/swallowing task × 40/60/80/100% maximum tongue pressure). Furthermore, the floor of the mouth (FOM) muscle activity during exercise was simultaneously measured using surface electromyography. During the pressing task, there were significant differences in FOM maximal muscle activity among the four exercise intensities for both the anterior and posterior oral tongue. For the swallowing task, a significant difference was found in FOM muscle activity among the four exercise intensities for the anterior tongue. For the posterior tongue, significant differences were identified among all conditions except for the comparison between 80% and 100% maximum tongue pressure. Significant correlations between the degree of tongue pressure and maximal FOM muscle activity were found in both the pressing and swallowing tasks at the anterior and posterior oral tongue. Overall, these results indicate that objective and systematic external resistance can be applied using the IOPI—a standard tongue pressure measurement device—during the program to improve suprahyoid muscle function.
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... Slovarp et al. noted that providing gradual resistance during ES is difficult. In addition, participants who had difficulty in swallowing repeatedly because of severe impairment of swallowing function could have limited participation in this exercise [35]. Kim et al. noted another limitation, which is that accurately quantifying the exercise intensity when applying ES as an exercise program is challenging [11]. ...
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View
... These factors are known to modulate the effect of exercise on directly involved (targeted) as well as indirectly involved (nontargeted) skeletal muscles, including exercise-related changes in strength and endurance (Tew et al. 2009;Karavirta et al. 2011a;Wilson et al. 2012b). Although the effect of some of these factors has been examined when the exercise was designed to directly target tongue muscles (Clark 2012;Van Nuffelen et al. 2015;Slovarp et al. 2016), it is currently unknown if these factors also impact tongue muscle performance when exercise targets skeletal muscles and only indirectly involves tongue muscles. Such information would be valuable to better understand how to promote healthy tongue muscle performance throughout the aging process. ...
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