Changes in the Activation Level of the Floor of the Mouth Muscles during Pressing and Swallowing Tasks According to the Degree of Tongue Pressure.

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.

Effect of Visual Biofeedback Obtained Using the Iowa Oral Performance Instrument on the Suprahyoid Muscle Activation Level During Effortful Swallowing Maneuver.

Effortful swallowing (ES) is a maneuver prescribed for patients who experience pharyngeal residues after swallowing owing to weakness of the tongue and pharyngeal constrictor muscles. ES can increase the pharyngeal contraction force by intentionally increasing the degree of effort during swallowing. However, the effect is limited as the nature of swallowing makes it difficult to maintain a constant high-effort level. The aim of this study was to assess the effect of visual feedback, delivered by the Iowa Oral Performance Instrument (IOPI), a tongue pressure measurement device on ES maneuver effort. Overall, 34 healthy adults performed five sets of ten ES, once every 10 s. The ES maneuver was conducted under two conditions, ES with and without IOPI biofeedback in a crossover design. IOPI biofeedback was provided at 80% of the maximum posterior oral tongue pressure. The suprahyoid muscle activation level was assessed using surface electromyography during the ES maneuver. The mean suprahyoid muscle activation levels in all sets for which IOPI biofeedback was provided were significantly higher than those during ES maneuver without biofeedback (p < 0.05). IOPI biofeedback can help maintain the ES maneuver target effort, utilizing a constantly high swallowing pressure potentially promoting better pharyngeal pressures and muscle strength.

Effects of Effortful Swallowing Exercise with Progressive Anterior Tongue Press Using Iowa Oral Performance Instrument (IOPI) on the Strength of Swallowing-Related Muscles in the Elderly: A Preliminary Study.

The purpose of this study was to confirm the effect of effortful swallowing (ES) exercise programs applied to increase the swallowing-related muscle strength in the elderly. In this study, 20 healthy elderly people (76.65 ± 5.87 years; 10 women and 10 men) participated and exercised for 7 weeks. The experimental group performed ES exercise combined with external resistance using Iowa Oral Performance Instrument (IOPI), and the control group performed pure ES without external resistance. The exercises were performed for 20 min a day, 2 days a week for 7 weeks in both groups. ES was repeated 60 times in weeks 1 and 2, 80 times in week 3 and 4, and 120 times in weeks 5-7. In the experimental group, the isometric and swallowing tongue pressures at week 8 were significantly improved compared to baseline. At week 8, the anterior and swallowing tongue pressures and anterior tongue endurance were significantly higher than those of the control group. In the control group, no significant change in tongue pressure-related variables was observed after 7 weeks of exercise. ES exercise combined with IOPI resistance for 7 weeks tended to increase the suprahyoid muscle activation level without statistical significance. For clinical application of this exercise protocol, further studies including more elderly people and patients with dysphagia are required.

Systematic Effortful Swallowing Exercise Without External Resistance Does Not Increase Swallowing-Related Muscle Strength in the Elderly.

Effortful swallow (ES) is a maneuver intended to increase pressure on a bolus by swallowing and pushing with sufficient force to facilitate clearance. Although ES is mainly known for its immediate effects, the long-term effects of applying ES as an exercise program remain unclear. This study investigated the effects of a 7-week systematic ES exercise regime on swallowing-related muscle strength in individuals aged 65 years and over. In total, 30 healthy older adults participated in this study (16 women and 14 men, aged 67-90 years). The subjects participated in the exercise program for 20 min a day, twice a week, for 7 weeks. To gradually increase exercise intensity, the number of exercises per session was increased from the initial 60 repetitions (weeks 1-2) to 120 repetitions (weeks 5-7). To measure the effect of the strengthening exercise program, the activation level of suprahyoid muscles was measured using surface electromyography, and a tongue pressure measurement system was used to measure variables related to tongue strength (isometric tongue pressure, swallowing tongue pressure, and tongue endurance). Although the effect of ES exercise on muscle strength through gradual adjustment of exercise frequency was not confirmed, ES remains valuable as an exercise for strengthening the muscles involved in swallowing. Future studies are warranted to determine the effects of ES exercise after adjusting for other variables of exercise intensity.

Effects of Resistive Jaw-Opening Exercise with Elastic Resistance Bands on Suprahyoid Muscle Activation and Tongue Strength in the Elderly: A Pilot Study.

BACKGROUND: The jaw-opening exercise (JOE) is designed to strengthen the suprahyoid muscles. However, it is difficult to apply this strength-training exercise to subjects in a systematic fashion. OBJECTIVE: This study examined the effect of resistive JOE on suprahyoid muscle activity and tongue strength in the elderly through the use of an elastic band. METHODS: Eight elderly people aged ≥65 years participated in this study. Participants wore an elastic loop around their head and mandible. The strength of the elastic loop used was adjusted based on the participant's sex, and the same strength loop was used for 8 weeks. Participants were required to open their jaw maximally, maintain the position for 10 s, and then rest for 10 s. This process was repeated for 10 min. There was then a rest period of 2 min before subjects began another 10-min exercise set. All participants performed the exercise twice weekly for 8 weeks. All subjects were tested for suprahyoid muscle activation during typical/effortful swallowing as well as isometric tongue pressures and endurances at baseline and at 9 weeks. RESULTS: After 8 weeks of exercise, the isometric maximum tongue-base pressure and tongue endurance were significantly improved. However, the swallowing tongue pressure and suprahyoid muscle activation levels had not changed significantly. CONCLUSION: This study confirmed that consistent resistance, which provides the same resistance throughout a resistive JOE exercise, is inadequate to reliably improve the muscle strength of swallowing-related muscles. Subsequent research should consider this and plan more efficient exercise programs.

Effects of Tongue-Hold Swallows on Suprahyoid Muscle Activation According to the Relative Tongue Protrusion Length in the Elderly Individuals.

This study investigated differences in suprahyoid muscle activity in elderly adults during tongue-hold swallowing (THS) according to tongue protrusion length to determine the most effective tongue protrusion length during THS. A total of 52 healthy participants (34 females and 18 males) aged 69-92 years were included. Changes in suprahyoid muscle activation during normal swallowing and THS with 1/3rd and 2/3rd tongue protrusions using surface electromyography were observed. Suprahyoid muscle activation significantly increased with the increasing tongue protrusion length (p < 0.05). Depending on the responses of the participants based on tongue protrusion length, participants were categorized into the increase group [increased suprahyoid muscle activity with tongue protrusion, n = 36 (1/3rd THS compared to normal swallowing) or 38 (2/3rd THS compared to normal swallowing)] or decrease group [decreased suprahyoid muscle activity with tongue protrusion, n = 16 (1/3rd THS compared to normal swallowing) or 14 (2/3rd THS compared to normal swallowing)]. The functional reserve of the increase group was significantly higher than that of the decrease group (p < 0.05). Many elderly people were found to have increased activation of the suprahyoid muscle during THS; however, others showed the opposite. Therefore, it is necessary to confirm the degree of suprahyoid muscle activation during THS so that the patient can perform the exercise at the tongue protrusion length that can maximize the effect of the exercise. For individuals who cannot overcome even a small amount of tongue protrusion (e.g., 1/3rd MTPL), replacing THS with another exercise may be considered.

Effect of partial head extension swallowing exercise on the strength of the suprahyoid and tongue muscles in healthy subjects: A feasibility study.

BACKGROUND: Head extension swallowing exercise (HESE) is one of the exercise methods to strengthen the suprahyoid muscle and tongue. In this study, we modified the exercise protocol of the original HESE for application in patients who have difficulty in performing full HESE owing to decreased muscular strength related to swallowing. OBJECTIVE: The purpose of this study was to investigate the feasibility and the effect of partial HESE on suprahyoid muscle activation and the tongue pressure during 30° extension of the head, rather than full extension, for 8 weeks. METHODS: Thirteen healthy young volunteers (mean age, 21.5 ± 1.13 years) participated in this study. The participants extended their head backward by 30° and swallowed their saliva every 10 seconds. The exercise was performed three times a week for 8 weeks. The effect of the exercise was confirmed by surface electromyography and tongue pressure measurement. The measurements were performed three times (baseline, at 4 weeks and at 8 weeks). RESULTS: No significant improvement in the tongue pressure-related parameters and suprahyoid muscle activation compared to those at baseline was observed as a result of the exercise. CONCLUSION: Although partial HESE in healthy adults did not lead to significant improvement in swallowing-related muscle strength, this study confirmed the feasibility of partial HESE. On the basis of these results, future studies should assess the applicability and effectiveness of partial HESE in elderly individuals and patients with dysphagia with swallowing-related muscular weakness.

Effects of Resistive Jaw-Opening Exercise with Elastic Bands on Suprahyoid Muscle Activation in Normal Subjects.

OBJECTIVE: The effect of a resistive jaw-opening exercise using an elastic band on suprahyoid muscle activity and tongue strength was examined in healthy volunteers. METHODS: Twenty-one adults wore an elastic loop around their head and mandible. To prescribe the appropriate elastic band resistance, the 10-repetition maximum (10 RM) was measured among 4 bands at baseline. Band loops, starting with the highest resistance value band, were sequentially applied to determine the suitability for 10 RM. During the exercise, the participants were required to open their jaw maximally and maintain the position for 10 s; then, they rested for 10 s. This procedure was repeated for 20 min, 3 days per week for 8 weeks to test suprahyoid muscle activation during effortful swallowing; isometric tongue pressures of the tongue tip and base at baseline, after 4, and after 8 weeks of training were measured. RESULTS: Peak suprahyoid muscle activation amplitudes during effortful swallow and isometric pressures at the tongue tip significantly increased after 8 weeks. CONCLUSION: The 8-week resistive jaw-opening exercise significantly improved strength of the suprahyoid muscle and tongue pressures in healthy subjects. These positive results warrant further investigation of the therapeutic effects and feasibility of this resistive exercise.

A Pilot Study of the Head Extension Swallowing Exercise: New Method for Strengthening Swallowing-Related Muscle Activity.

This pilot study examined the effect of a new head extension swallowing exercise (HESE) on submental muscle activity and tongue strength in healthy volunteers. Fifteen young adults (10 females and 5 males) were instructed to extend their head backwards as much as possible, and while watching the ceiling, swallowed their saliva every 10 s for a duration of 20 min. Twenty-four treatments were performed over 8 weeks. The outcome variables evaluated at baseline, 4 and 8 weeks of training, and 12-week follow-up included mean and peak submental muscle activation amplitudes during normal and effortful swallowing measured via surface electromyography, and anterior and posterior isometric tongue pressures were measured with the Iowa Oral Performance Instrument. Results indicated that the muscle activation amplitudes during effortful swallowing increased significantly at 4 and 8 weeks compared to baseline (p < 0.025). However, the increases in amplitudes during normal swallowing were minor (nonsignificant) after 8 weeks compared to baseline. The isometric pressures of the tongue tip and the posterior part of the oral tongue were significantly higher at 8 weeks compared to baseline (p < 0.025). Thus, the 8-week HESE protocol significantly improved suprahyoid muscle activity during effortful swallowing as well as the isometric tongue pressures. The HESE appears effective in exercising and strengthening the suprahyoid muscles and tongue muscles in healthy participants. Although encouraging, these results need to be replicated in clinical trials for testing the therapeutic effects of the HESE in older adults and patients with dysphagia who present with decreased hyolaryngeal elevation.

Effects of asymmetric sitting on spinal balance.

[Purpose] To investigate the effects of two common asymmetric sitting positions on spinal balance. [Subjects and Methods] Thirty-seven healthy subjects in their twenties were enrolled and randomly divided into two groups. Asymmetric positions of resting the chin on a hand and crossing the legs were performed by each group for 1 hour. After 1 hour, the subjects lay in the supine position again and spinal imbalance was measured using a device. [Results] After 1 hour of resting with the chin on a hand, sagittal imbalance, coronal imbalance, pelvic obliquity and lordosis angle presented spinal imbalance worsening of 1 hour of crossing legs, sagittal imbalance, pelvic torsion showed in mainly learned spinal imbalance living. [Conclusion] Good posture could be an innate ability, however it through habits. So this study is meaningful from the perspective of the importance of good posture.

Effects of Tongue Strength Training and Detraining on Tongue Pressures in Healthy Adults.

This study examined the effect of tongue strengthening training and long-term detraining on tongue tip pressure, tongue base pressure, and tongue pressure during effortful swallowing. Ten young healthy volunteers (21-35 years) were participated in this study. Participants received 8-week tongue strengthening exercise 3 days a week with each session lasting 30 min. Measurement of tongue pressure and tongue strengthening exercise were administrated using Iowa Oral Performance Instrument (IOPI). Training intensity was applied at 60 and 80% of maximal tongue pressure for the first week and the remainder, respectively. Following completion of 8-week training, 28 weeks of detraining period was continued. Training increased tongue tip pressure, tongue base pressure, and tongue pressure during effortful swallowing above pre-training values (p < 0.05). After 28-week detraining, all tongue variables were significantly lower than after 8-week training (p < 0.05) but remained significantly higher than pre-training levels (p < 0.05). These findings demonstrate that high-intensity tongue strengthening exercise can improve tongue pressures. However, training effects were diminished gradually during detraining period. Thus, maintenance programs after strengthening exercise would be required for prolonging training effects.

Effortful swallowing training combined with electrical stimulation in post-stroke dysphagia: a randomized controlled study.

We tested the effect of effortful swallow combined with surface electrical stimulation used as a form of resistance training in post-stroke patients with dysphagia. Twenty post-stroke dysphagic patients were randomly divided into two groups: those who underwent effortful swallow with infrahyoid motor electrical stimulation (experimental group, n = 10) and effortful swallow with infrahyoid sensory electrical stimulation (control group, n = 10). In the experimental group, electrical stimulation was applied to the skin above the infrahyoid muscle with the current was adjusted until muscle contraction occurred and the hyoid bone was depressed. In the control group, the stimulation intensity was applied just above the sensory threshold. The patients in both groups were then asked to swallow effortfully in order to elevate their hyolaryngeal complex when the stimulation began. A total of 12 sessions of 20 min of training for 4 weeks were performed. Blinded biomechanical measurements of the extent of hyolaryngeal excursion, the maximal width of the upper esophageal sphincter (UES) opening, and the penetration-aspiration scale before and after training were performed. In the experimental group, the maximal vertical displacement of the larynx was increased significantly after the intervention (p < 0.05). The maximal vertical displacement of the hyoid bone and the maximal width of the UES opening increased but the increase was not found to be significant (p = 0.066). There was no increase in the control group. Effortful swallow training combined with electrical stimulation increased the extent of laryngeal excursion. This intervention can be used as a new treatment method in post-stroke patients with dysphagia.

Effortful swallowing training coupled with electrical stimulation leads to an increase in hyoid elevation during swallowing.

We tested the effects of surface electrical stimulation on hyoid elevation during swallowing in healthy volunteers. Sixteen people were recruited and randomly divided into two groups. Electrical stimulation was applied to the skin above the infrahyoid muscle in the experimental group. The stimulation current was adjusted until muscle contraction occurred and the hyoid bone became depressed. Participants were asked to swallow forcefully so as to elevate the hyolaryngeal complex when the stimulation began. The same experiment was performed in the control group except the intensity of stimulation was adjusted to just above the sensory threshold. The two groups received ten 20-min treatments over 2 weeks. We recorded the myoelectrical activity of the submental muscles and the amount of hyoid bone movement at three time points (pretreatment, immediately post-treatment, and 2 weeks after treatment). In the experimental group, the amount of y-axis hyoid bone excursion was increased immediately post-treatment, but this effect faded within 2 weeks following the treatment. Myoelectrical activity was not affected by either treatment regimen. We concluded that effortful swallowing coupled with electrical stimulation increases the degree of hyoid elevation in healthy volunteers. It needs to be evaluated for its long-term effectiveness in increasing the elevation of hyolaryngeal complex.

Effect of the head extension swallowing exercise on suprahyoid muscle activity in elderly individuals.

Aging causes motor function deterioration in the elderly population, which in turn can cause weakness in the muscles associated with swallowing. Swallowing-related problems in elderly individuals can be prevented or their symptoms can be improved with strengthening exercises for the muscles involved in swallowing. The existing strengthening exercises for the suprahyoid muscle have their limitations. Therefore, it is necessary to find another exercise that can be performed by individuals whose personal characteristics make it difficult for them to perform the existing exercises. In this study, we investigated the changes in suprahyoid muscle activation, tongue strength, and thickness of the suprahyoid muscle after 8 weeks of the head extension swallowing exercise (HESE). A total of 23 healthy elderly individuals participated in an 8-week exercise program (20 min/session, 2 times/week for 8 weeks). Suprahyoid muscle activation during effortful swallowing and the effortful-normal ratio were significantly increased at 8 weeks compared to the baseline values (p = 0.002, and 0.033, respectively). Tongue tip pressure, tongue base pressure, normal swallowing pressure, effortful swallowing pressure, and tongue tip endurance were significantly increased at 8 weeks compared with baseline (p = 0.014, 0.004, 0.046, 0.009, and 0.004, respectively). The thickness of the digastric muscle and that of the mylohyoid muscle were significantly increased at 8 weeks compared with baseline (p = 0.000 and 0.004, respectively). This study showed that HESE can be a good option for improving the suprahyoid muscle and tongue strength in the elderly population. Additionally, this exercise does not require any additional equipment and has the advantage of being able to be performed anytime and anywhere. A variety of exercise options tailored according to individual characteristics may be helpful in choosing the most appropriate exercise.

Effects of tongue-hold swallows on suprahyoid muscle activation according to the relative tongue protrusion length: a preliminary study.

Tongue-hold swallow (THS) is a therapeutic maneuver used to increase the posterior pharyngeal wall motion during swallowing. This maneuver has also been reported to result in increased activation of the suprahyoid muscles. The hypothesis of this study was that the degree of suprahyoid muscle activation would depend on the tongue protrusion-length. The aim of this study was to investigate the activation levels of the suprahyoid muscles by surface electromyography (sEMG) while performing the THS maneuver at three tongue-protrusion lengths. Suprahyoid muscle activity during THSs was recorded in 25 adult volunteers (17 women and 8 men; age range 20-38 years). To record the activity of the suprahyoid muscles while the participants performed the maneuver, surface wireless EMG electrodes separated by a distance of 1 cm were placed on the skin on both sides of the midline under the chin. Each activity was recorded three times. Data analysis was performed by repeated-measures analysis of variance. Our results revealed that participants exhibited greater electrical activity during THS with 2/3rd or maximal tongue protrusion as compared to THS with 1/3rd tongue protrusion (p ≤ 0.001). To maximize the therapeutic effect of the THS maneuver, it is advised to protrude the tongue maximally as long as swallowing is possible.

Relationship between Quantified Instrumental Swallowing Examination and Comprehensive Clinical Swallowing Examination.

The aim of this study was to identify the correlation between the Mann Assessment of Swallowing Ability (MASA) and the Videofluoroscopic Dysphagia Scale (VDS) to investigate the applicability of the MASA as a follow-up test of swallowing function. Criterion validity was assessed for MASA results versus VDS scores of tests administered to 54 patients who had a stroke and dysphagia. A significant correlation was found between the MASA and the VDS (correlation coefficient = -0.509). In analyses of test-re-test reliability and inter-rater reliability of the scoring scale, intraclass correlation coefficients (2, 1) were high (0.98, 0.99). In conclusion, the results of the present study indicate that the MASA holds adequate clinical test-re-test and inter-rater reliabilities and criterion validity for measuring the swallowing abilities of Korean patients who had a stroke and dysphagia. The MASA could contribute to more systematic management of swallowing problems and efficient therapeutic service.