Expiratory muscle training and sensation of respiratory effort during exercise in normal subjects

Effect of expiratory muscle training on respiratory muscle fatigue in healthy adults: a randomized controlled trial

[Purpose] This study examined the effects of expiratory muscle training on fatigue in individual respiratory muscles. [Participants and Methods] Healthy adult males (n=31) were randomly assigned to two groups: expiratory muscle training (n=15) and normal controls (n=16). In the expiratory muscle training group, training was performed once for 15 min at 50% load of the maximum expiratory mouth pressure twice daily for 4 weeks. Respiratory muscle fatigue indicators were measured using surface electromyography as the median power frequency of each respiratory muscle at the time of measuring the maximum inspiratory mouth pressure during 20 min of inspiratory muscle loading and maximum expiratory mouth pressure. [Results] In the expiratory muscle training group, the median power frequency values of the sternocleidomastoid, rectus abdominis, and internal oblique/external oblique before expiratory muscle training significantly decreased during inspiratory muscle loading. However, no difference was observed in the median power frequency values measured before and during inspiratory muscle loading after the expiratory muscle training. In the normal controls, the median power frequency values of the sternocleidomastoid and rectus abdominis significantly decreased during inspiratory muscle loading. [Conclusion] Expiratory muscle training increased fatigue tolerance of the sternocleidomastoid, rectus abdominis, and internal and external oblique muscles in healthy individuals.

Inspiratory muscle training impact on respiratory muscle strength, pulmonary function, and quality of life in children with chest burn: A randomized controlled trial

PURPOSE

Respiratory muscle function is compromised in children recovering from chest wall burns, which potentially leads to more impact on exercise capacity and quality of life. This study investigates the effects of an inspiratory muscle training intervention accompanied with a pulmonary rehabilitation program on respiratory muscle strength, lung function, functional capacity, and quality of life in chest burned children.

METHODS

Forty children with burns, aged from 10 to 18 years old and total body surface area of 30% to 50%, were randomly allocated to the inspiratory muscle training group (IMT- G: n = 20) or control group (CG: n = 20). They received IMT plus pulmonary rehabilitation or pulmonary rehabilitation with sham IMT, respectively for eight weeks. The outcomes were the respiratory muscle strength measured by maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP); lung functions (FEV1, FVC and FEV1/FVC ratio); functional capacity as well as Pediatric Quality of Life to measure physical and psychosocial functioning. outcome measures were assessed at before and after intervention (after eight weeks).

RESULTS

Based on the pre-intervention assessments, we found no significant difference between both groups (p > 0.05). Significant post-intervention differences were reported between both groups in MIP (P = .003), MEP (P = .017), FVC (P = .001), FEV1 (P = .007), FEV1/FVC ratio (P = .028), functional capacity (P = .003), physical domain of QoL (P = .006) and psychological domain of QoL (P = .002) in favor of the IMT group.

CONCLUSIONS

Eight weeks of inspiratory muscle training combined with pulmonary rehabilitation program improved children with chest burns' respiratory muscles strength, lung functions, functional capacity, and quality of life. Inspiratory muscle training may be employed in burn rehabilitation programs. It is a safe and effective therapy in chest burned children.

Feasibility of oropharyngeal and respiratory muscle training in individuals with OSA and spinal cord injury or disease: A pilot study

OBJECTIVES

To examine the feasibility of individuals with spinal cord injury or disease (SCI/D) to perform combined oropharyngeal and respiratory muscle training (RMT) and determine its impact on their respiratory function.

METHODS

A prospective study at a single Veterans Affairs (VA) Medical Center. Inclusion criteria included: 1) Veterans with chronic SCI/D (>6 months postinjury and American Spinal Injury Association (ASIA) classification A-D) and 2) evidence of OSA by apnea-hypopnea index (AHI ≥5 events/h). Eligible participants were randomly assigned to either an experimental (exercise) group that involved performing daily inspiratory, expiratory (using POWERbreathe and Expiratory Muscle Strength Trainer 150 devices, respectively), and tongue strengthening exercises or a control (sham) group that involved using a sham device, for a 3-month period. Spirometry, maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), polysomnography, and sleep questionnaires were assessed at baseline and at 3 months.

RESULTS

Twenty-four individuals were randomized (12 participants in each arm). A total of eight (67%) participants completed the exercise arm, and ten (83%) participants completed the sham arm. MIP was significantly increased (p < 0.05) in the exercise group compared with the baseline.

CONCLUSIONS

Combined oropharyngeal and RMT are feasible for individuals with SCI/D. Future studies are needed to determine the clinical efficacy of these respiratory muscle exercises.

Similar effects on exercise performance following different respiratory muscle training programs in healthy young men

Both respiratory muscle endurance training (RMET) and inspiratory resistive training (IMT) seem to increase whole-body exercise performance, but direct comparisons between the two are scarce. We hypothesized that the similarity of RMET to exercise-induced ventilation would induce larger improvements compared to IMT. Twenty-six moderately-trained men performed either 4 weeks of RMET, IMT or SHAM training. Before and after the interventions, respiratory muscle endurance, 3-km running time-trial performance and leg muscle fatigue after intense constant-load cycling (assessed with femoral nerve magnetic stimulation) were measured. Both RMET (+ 59%) and IMT (+ 38%) increased respiratory muscle endurance (both p < 0.01 vs. SHAM) but only IMT increased inspiratory strength (+ 32%, p < 0.001 vs. SHAM). 3-km time improved showing a main effect of training (p = 0.026), however with no differences between groups. Leg fatigue after cycling was not attenuated with training (p = 0.088 for group-training interaction). All groups showed a significant (~ 0.3 l) increase in average tidal volume during cycling exercise combined with a concomitant reduction in respiratory exertion. While RMET and IMT improved specific aspects of respiratory muscles performance, no benefits beyond SHAM were seen during whole-body exercise. Changes in respiratory sensations might be a result of altered breathing pattern.

Effects of Sprint Interval and Endurance Respiratory Muscle Training on Postcycling Inspiratory and Quadriceps Fatigue

PURPOSE

We investigated whether a 4-wk period of respiratory muscle endurance training (RMET) or respiratory muscle sprint interval training (RMSIT) would lead to an attenuation of inspiratory muscle and quadriceps fatigue after a bout of high-intensity cycling compared with a placebo intervention (PLAT), as predicted by the respiratory metaboreflex model.

METHODS

Thirty-three active, young healthy adults performed RMET, RMSIT, or PLAT. Changes in inspiratory muscle and quadriceps twitches in response to a cycling test at 90% of peak work capacity were assessed before and after training. EMG activity and deoxyhemoglobin (HHb, via near-infrared spectroscopy) of the quadriceps and inspiratory muscles were also monitored during the cycling test, along with cardiorespiratory and perceptual variables.

RESULTS

At pretraining, cycling reduced the twitch force of the inspiratory muscles (86% ± 11% baseline) and quadriceps (66% ± 16% baseline). Training did not attenuate the drop in twitch force of the inspiratory muscles (PLAT, -3.5 ± 4.9 percent-points [p.p.]; RMET, 2.7 ± 11.3 p.p.; RMSIT, 4.1 ± 8.5 p.p.; group-training interaction, P = 0.394) or quadriceps (PLAT, 3.8 ± 18.6 p.p.; RMET, -2.6 ± 14.0 p.p.; RMSIT, 5.2 ± 9.8 p.p.; group-training interaction P = 0.432). EMG activity and HHb levels during cycling did not change after training for either group. Only RMSIT showed a within-group decrease in the perception of respiratory exertion with training.

CONCLUSIONS

Four weeks of RMET or RMSIT did not attenuate the development of exercise-induced inspiratory or quadriceps fatigue. The ergogenic effects of respiratory muscle training during whole-body exercise might be related to an attenuation of perceptual responses.

The RESISTANT study (Respiratory Muscle Training in Patients with Spinal Muscular Atrophy): study protocol for a randomized controlled trial

BACKGROUND

Spinal Muscular Atrophy (SMA) is characterized by progressive and predominantly proximal and axial muscle atrophy and weakness. Respiratory muscle weakness results in impaired cough with recurrent respiratory tract infections, nocturnal hypoventilation, and may ultimately lead to fatal respiratory failure in the most severely affected patients. Treatment strategies to either slow down the decline or improve respiratory muscle function are wanting.

OBJECTIVE

The aim of this study is to assess the feasibility and efficacy of respiratory muscle training (RMT) in patients with SMA and respiratory muscle weakness.

METHODS

The effect of RMT in patients with SMA, aged ≥ 8 years with respiratory muscle weakness (maximum inspiratory mouth pressure [PImax] ≤ 80 Centimeters of Water Column [cmH2O]), will be investigated with a single blinded randomized sham-controlled trial consisting of a 4-month training period followed by an 8-month open label extension phase.

INTERVENTION

The RMT program will consist of a home-based, individualized training program involving 30-breathing cycles through an inspiratory and expiratory muscle training device. Patients will be instructed to perform 10 training sessions over 5-7 days per week. In the active training group, the inspiratory and expiratory threshold will be adjusted to perceived exertion (measured on a Borg scale). The sham-control group will initially receive RMT at the same frequency but against a constant, non-therapeutic resistance. After four months the sham-control group will undergo the same intervention as the active training group (i.e., delayed intervention). Individual adherence to the RMT protocol will be reviewed every two weeks by telephone/video call with a physiotherapist.

MAIN STUDY PARAMETERS/ENDPOINTS

We hypothesize that the RMT program will be feasible (good adherence and good acceptability) and improve inspiratory muscle strength (primary outcome measure) and expiratory muscle strength (key secondary outcome measure) as well as lung function, patient reported breathing difficulties, respiratory infections, and health related quality of life (additional secondary outcome measures, respectively) in patients with SMA.

DISCUSSION

RMT is expected to have positive effects on respiratory muscle strength in patients with SMA. Integrating RMT with recently introduced genetic therapies for SMA may improve respiratory muscle strength in this patient population.

TRIAL REGISTRATION

Retrospectively registered at clinicaltrial.gov: NCT05632666.

Differential control of respiratory frequency and tidal volume during exercise

The lack of a testable model explaining how ventilation is regulated in different exercise conditions has been repeatedly acknowledged in the field of exercise physiology. Yet, this issue contrasts with the abundance of insightful findings produced over the last century and calls for the adoption of new integrative perspectives. In this review, we provide a methodological approach supporting the importance of producing a set of evidence by evaluating different studies together-especially those conducted in 'real' exercise conditions-instead of single studies separately. We show how the collective assessment of findings from three domains and three levels of observation support the development of a simple model of ventilatory control which proves to be effective in different exercise protocols, populations and experimental interventions. The main feature of the model is the differential control of respiratory frequency (f_R) and tidal volume (V_T); f_R is primarily modulated by central command (especially during high-intensity exercise) and muscle afferent feedback (especially during moderate exercise) whereas V_T by metabolic inputs. Furthermore, V_T appears to be fine-tuned based on f_R levels to match alveolar ventilation with metabolic requirements in different intensity domains, and even at a breath-by-breath level. This model reconciles the classical neuro-humoral theory with apparently contrasting findings by leveraging on the emerging control properties of the behavioural (i.e. f_R) and metabolic (i.e. V_T) components of minute ventilation. The integrative approach presented is expected to help in the design and interpretation of future studies on the control of f_R and V_T during exercise.

Acute psychophysiological responses during exercise while using resistive respiratory devices: A systematic review

Different studies have observed that respiratory muscle training (RMT) improve the endurance and strength of the respiratory muscles, having a positive impact on performance of endurance sports. Nevertheless, it remains to be clarified how to improve the efficiency of such training. The objective of this systematic review was to evaluate the acute physiological responses produced by training the respiratory muscles during exercise with flow resistive devices because such information may support us improve the efficiency of this type of training. A search in the Medline, Science Direct, Web of Science and Scopus databases was conducted, following the PRISMA guidelines. The methodological quality of the articles was assessed using the PEDro scale. Nineteen studies met the inclusion criteria and a total of 212 subjects were included in the studies. The RMT method used in all studies was flow resistive loading, whereas the constant load exercise was the most common type of exercise among the studies. The results obtained seem to indicate that the use of this type of training during exercise reduces the performance, the lactate (La^-) values and the ventilation, whereas the end - tidal partial pressure of carbon dioxide (P_CO2) is increased.

Immediate changes in chest mobility and trunk muscle activity during pelvic tilt following different trunk muscle exercises

BACKGROUND

Given the characteristics of the superficial trunk muscles that cross the chest and pelvis, their excessive contraction might limit chest mobility.

OBJECTIVE

To examine the immediate effects of two types of trunk muscle exercises on chest mobility and trunk muscle activities.

METHODS

Fourteen healthy men (age: 21.1 ± 1.0 years, height: 172.7 ± 5.6 cm, weight: 61.0 ± 7.1 kg, body mass index: 20.4 ± 1.7 kg/m2; mean ± SD) randomly performed trunk side flexion and draw-in exercises using a cross-over design. The chest kinematic data and trunk muscle activities were measured before and after each intervention during the following tasks: maximum inspiration/expiration and maximum pelvic anterior/posterior tilt while standing. Two-way repeated measures analysis of variance was used for statistical analysis (P< 0.05).

RESULTS

After the side flexion, upper and lower chest mobility significantly decreased, and superficial trunk muscle activity significantly increased during the maximum pelvic anterior tilt (P< 0.05). Additionally, after the draw-in, upper chest mobility significantly increased during the maximum pelvic anterior tilt (P< 0.05).

CONCLUSIONS

Increased activity of the superficial abdominal muscles might limit chest mobility during maximum pelvic anterior tilt. Conversely, the facilitation of deep trunk muscles might increase upper chest mobility during the maximum pelvic anterior tilt.

The Efficacy of Expiratory Muscle Training during Inspiratory Load in Healthy Adult Males: A Randomized Controlled Trial

This study aimed to evaluate the effects of expiratory muscle training (EMT) on respiratory muscle strength and respiratory distress during inspiratory load. Thirty-one healthy adult males were randomly divided into an EMT group who underwent EMT (n = 15) and a control group who did not undergo EMT (n = 16). The EMT group underwent EMT with a 50% load of maximum expiratory mouth pressure (PEmax) for 15 min, twice a day, every day, for 4 weeks. The parameter of respiratory muscle fatigue was a decrease in maximum inspiratory mouth pressure (PImax) and PEmax during 20 min of inspiratory load; thus, PImax and PEmax during inspiratory load were measured. Respiratory distress during inspiratory load was assessed using the Borg scale. These assessments were performed on the same subjects in each group before and after the 4 week study. In the EMT group, the PEmax values after the study were significantly higher than those before the study (p < 0.01). Furthermore, before the study, the PImax and PEmax values for the EMT group during inspiratory load were significantly lower than those before inspiratory load (p < 0.01). However, after the study, there was no difference in these values between during and before inspiratory load. In the EMT group, the Borg scale value during inspiratory load from 6 to 20 min was significantly lower after the study than before the study (p < 0.05). EMT increases expiratory muscle strength, thereby attenuating decreased respiratory muscle strength (PImax and PEmax) and respiratory distress during inspiratory load in healthy subjects.

Facemasks during aerobic exercise: Implications for cardiac rehabilitation programs during the Covid-19 pandemic

Introduction and objectives

During the COVID-19 pandemic, among the safety measures adopted, use of facemasks during exercise training sessions in cardiac rehabilitation programs raised concerns regarding possible detrimental effects on exercise capacity. Our study examined the cardiorespiratory impact of wearing two types of the most common facemasks during treadmill aerobic training.

Methods

Twelve healthy health professionals completed three trials of a symptom-limited Bruce treadmill protocol: Without a mask, with a surgical mask and with a respirator. Perceived exertion and dyspnea were evaluated with the Borg Scale of Perceived Exertion and the Borg Dyspnea Scale, respectively. Blood pressure, heart rate and arterial oxygen saturation (SpO2) were measured at each 3-minute stage.

Results

Using a surgical mask or a respirator resulted in a shorter duration of exercise testing. At peak capacity, using a respirator resulted in higher levels of dyspnea and perceived exertion compared to not wearing a facemask. A significant drop in SpO2 was present at the end of exercise testing only when using a respirator. There were no differences in either chronotropic or blood pressure responses between testing conditions.

Conclusions

Professionals involved in cardiac rehabilitation should be aware of the cardiorespiratory impact of facemasks. Future studies should assess whether exposure to these conditions may impact on the overall results of contemporary cardiac rehabilitation programs.

Facemasks during aerobic exercise: Implications for cardiac rehabilitation programs during the Covid-19 pandemic

Introduction and objectives

During the COVID-19 pandemic, among the safety measures adopted, use of facemasks during exercise training sessions in cardiac rehabilitation programs raised concerns regarding possible detrimental effects on exercise capacity. Our study examined the cardiorespiratory impact of wearing two types of the most common facemasks during treadmill aerobic training.

Methods

Twelve healthy health professionals completed three trials of a symptom-limited Bruce treadmill protocol: Without a mask, with a surgical mask and with a respirator. Perceived exertion and dyspnea were evaluated with the Borg Scale of Perceived Exertion and the Borg Dyspnea Scale, respectively. Blood pressure, heart rate and arterial oxygen saturation (SpO2) were measured at each 3-minute stage.

Results

Using a surgical mask or a respirator resulted in a shorter duration of exercise testing. At peak capacity, using a respirator resulted in higher levels of dyspnea and perceived exertion compared to not wearing a facemask. A significant drop in SpO2 was present at the end of exercise testing only when using a respirator. There were no differences in either chronotropic or blood pressure responses between testing conditions.

Conclusions

Professionals involved in cardiac rehabilitation should be aware of the cardiorespiratory impact of facemasks. Future studies should assess whether exposure to these conditions may impact on the overall results of contemporary cardiac rehabilitation programs.

Endurance and Resistance Respiratory Muscle Training and Aerobic Exercise Performance in Hypobaric Hypoxia

INTRODUCTION: Hypoxia-induced hyperventilation is an effect of acute altitude exposure, which may lead to respiratory muscle fatigue and secondary locomotor muscle fatigue. The purpose of this study was to determine if resistive and/or endurance respiratory muscle training (RRMT and ERMT, respectively) vs. placebo respiratory muscle training (PRMT) improve cycling performance at altitude.METHODS: There were 24 subjects who were assigned to PRMT (N 8), RRMT (N 8), or ERMT (N 8). Subjects cycled to exhaustion in a hypobaric chamber decompressed to 3657 m (12,000 ft) at an intensity of 55% sea level maximal oxygen consumption (Vo_2max) before and after respiratory muscle training (RMT). Additionally, subjects completed a Vo_2max, pulmonary function, and respiratory endurance test (RET) before and after RMT. All RMT protocols consisted of three 30-min training sessions per week for 4 wk.RESULTS: The RRMT group increased maximum inspiratory (P_Imax) and expiratory (P_Emax) mouth pressure after RMT (P_Imax: 117.7 11.6 vs. 162.6 20.0; P_Emax: 164.0 33.2 vs. 216.5 44.1 cmH₂O). The ERMT group increased RET after RMT (5.2 5.2 vs.18.6 16.9 min). RMT did not improve Vo_2max in any group. Both RRMT and ERMT groups increased cycling time to exhaustion (RRMT: 35.9 17.2 vs. 45.6 22.2 min and ERMT: 33.8 9.6 vs. 42.9 27.0 min).CONCLUSION: Despite different improvements in pulmonary function, 4 wk of RRMT and ERMT both improved cycle time to exhaustion at altitude.Wheelock CE, Hess HW, Johnson BD, Schlader ZJ, Clemency BM, St. James E, Hostler D. Endurance and resistance respiratory muscle training and aerobic exercise performance in hypobaric hypoxia. Aerosp Med Hum Perform. 2020; 91(10):776784.

Inspiratory Muscle Training in Intermittent Sports Modalities: A Systematic Review

The fatigue of the respiratory muscles causes the so-called metabolic reflex or metaboreflex, resulting in vasoconstriction of the blood vessels in the peripheral muscles, which leads to a decrease in respiratory performance. Training the respiratory muscles is a possible solution to avoid this type of impairment in intermittent sports. The objective of this systematic review was to evaluate the results obtained with inspiratory muscle training (IMT) in intermittent sports modalities, intending to determine whether its implementation would be adequate and useful in intermittent sports. A search in the Web of Science (WOS) and Scopus databases was conducted, following the Preferred Reporting Elements for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The methodological quality of the articles was assessed using the PEDro (Physiotherapy Evidence Database) scale. In conclusion, the introduction of specific devices of IMT seems to be a suitable method to improve performance in intermittent sports, mainly due to a reduction of the metaboreflex, fatigue sensation, and dyspnea. The ideal protocol would consist of a combination of acute and chronic treatment, and, even if IMT is done daily, the duration will not exceed one hour per week.

Effects of Humidification of the Vocal Tract and Respiratory Muscle Training in Women With Voice Symptoms-A Pilot Study

OBJECTIVE

The aim of this study was to determine the efficacy of a 4-week breathing exercise intervention in participants with voice symptoms.

METHODS

Six nonsmoking women (mean age 49) experiencing voice symptoms used a novel device WellO₂ for respiratory exercises that provides counter pressure during both inspiration and expiration and warms and humidifies the breathing air. Speech samples were acoustically (Acoustic Voice Quality Index) and perceptually (grade, roughness, breathiness, asthenia, and strain scale) analyzed, and perceived voice symptoms and self-reported effort in breathing and phonation were obtained. Respiratory measurements included breathing frequency and pattern, peak expiratory flow, forced vital capacity, and forced expiratory volume in 1 minute.

RESULTS

The total scores of Acoustic Voice Quality Index and some of its subcomponents (shimmer and harmonic-to-noise ratio), and the grade, roughness, and strain of the GRBAS scale indicated significantly improved voice quality. However, neither the nature or frequency of the experienced voice symptoms nor the perceived phonatory effort changed as the function of intervention. According to the participants, their breathing was significantly less effortful after the intervention, although no significant changes were observed in the objective respiratory measurements with a spirometer.

CONCLUSION

Training with the WellO₂ device has the potential to improve voice quality. The combination of inspiratory and expiratory training and warmed, humidified air is a multifaceted entity influencing several parts in the physiology of voice production. The effects of using WellO₂ need to be confirmed by further studies with a larger number of participants.

The application of "upper-body yoga" in elderly patients with acute hip fracture: a prospective, randomized, and single-blind study

Purposes

Hip fracture leads to decreased activity and an increased risk of pulmonary complications. The main purpose of this study was to observe the lung capacity, cough capacity of the elderly patient with acute hip fracture, and assess the effects and the feasibility of using a special-designed “upper-body yoga” training to treat elderly patients with hip fracture.

Methods

This was a prospective, randomized, and single-blind study. Eighty-four subjects aged over 65 years were randomly divided into either a control group or a yoga group to undergo an abdominal breathing program or an “upper-body yoga” program until 4 weeks after surgery. The primary outcomes were forced vital capacity/predicted value (FVC%), peak cough flow (PCF), Barthel Index (BI), and the incidence of pneumonia. The secondary outcomes were the rates of right skills and inclination.

Results

Thirty-nine subjects in the yoga group and 40 subjects in the control group completed this study. At the end of the first training week, FVC% (74.14% ± 13.11% vs. 70.87% ± 10.46%, P = 0.231) showed no significant difference between the two groups, while the value of PCF (204.80 ± 33.45 L/min vs. 189.06 ± 34.80 L/min, P = 0.048) and BI (38.59 ± 8.66 vs. 33.00 ± 9.32, P = 0.009) in the yoga group was higher. After 4 weeks of treatment, FVC%, PCF, and BI were higher in the yoga group (78.83% ± 13.31 % vs. 72.20% ± 10.53%, P = 0.016; 216.16 ± 39.29 L/min vs. 194.95 ± 31.14 L/min, P = 0.008; 70.77 ± 10.23 vs. 65.75 ± 11.30, P = 0.019). One in the control group and nobody in the yoga group was diagnosed with pneumonia. There was no significant difference between the two groups in terms of the rates of right skills, whereas more elderly people preferred the training program of the “upper-body yoga.”

Conclusion

Elderly patients with acute hip fractures are at risk of impaired lung capacity and inadequate cough. “Upper-body yoga” training may improve the quality of daily life, vital capacity, and cough flow in elderly patients, making it a better choice for bedridden patients with hip fracture.

Effectiveness of expiratory muscle strength training on expiratory strength, pulmonary function and cough in the adult population: a systematic review

BACKGROUND

Respiratory muscle strength declines in certain disease states, leading to impaired cough, reduced airway clearance and an increased risk of aspiration pneumonia. Respiratory muscle training may therefore reduce this risk.

OBJECTIVES

To assess current evidence of expiratory muscle strength training (EMST) on maximum expiratory pressure, cough flow and spirometry.

DATA SOURCES

Databases including CINAHL, Medline, Science Direct and PEDRo were searched.

ELIGIBILITY CRITERIA

Randomised controlled trials investigating expiratory muscle strength training on maximum expiratory pressure, pulmonary function or cough in any adult population, published before December 2017.

STUDY APPRAISAL

Data were extracted to a trial description form and study quality evaluated by two reviewers. Meta-analysis was performed with calculation of mean differences and 95% confidence intervals.

RESULTS

Nine studies met inclusion criteria and ranged in size from 12 to 42 participants. Trials investigated EMST in healthy adults (2), multiple sclerosis (3), COPD (2), acute stroke (1) and spinal cord injury (1). Overall, EMST improved maximum expiratory pressure (15.95cmH₂O; 95% CI: 7.77 to 24.12; P<0.01) with no significant impact on cough flow (4.63L/minute; 95%CI -27.48 to 36.74; P=0.78), forced vital capacity (-0.16L; 95%CI -0.35 to 0.02; P=0.09) or forced expiratory volume in 1second (-0.09L; 95%CI -0.10 to -0.08; P<0.001) vs control or sham training.

CONCLUSIONS

Meta-analysis indicated a small significant increase in maximum expiratory pressure following EMST. Improvements in maximum expiratory pressure did not lead to improvements in cough or pulmonary function.

LIMITATIONS

Variations in protocol design and population limited the overall effect size. Systematic Review Registration PROSPERO CRD42018104190.

The Effects of Respiratory Muscle Training on Phonatory Measures in Individuals with Parkinson's Disease

INTRODUCTION

In individuals with Parkinson's disease (PD), respiratory muscle weakness and rigidity, bradykinesia of abdominal muscles and stiffness of the chest wall, affect the respiratory component of voice intensity due to reduced pulmonary capacity and airflow needed to vibrate the vocal folds. It may be possible to improve voice production by strengthening respiratory muscles. The purpose of this study was to evaluate the effects of inspiratory and expiratory muscle training on voice production outcomes in individuals with PD.

METHOD

Thirty-one participants with PD were randomly allocated to three study groups (control group n = 10, inspiratory training group, n = 11, and expiratory training group, n = 11). The inspiratory and expiratory group performed a home-based inspiratory and expiratory muscle training program, respectively (five sets of five repetitions). Both groups trained six times a week for 2 months using a progressively increased resistance. The control group performed expiratory muscle training using the same protocol and a fixed resistance. Phonatory measures, maximum inspiratory/expiratory pressure, and spirometric indexes were assessed before and at 2 months after training.

RESULTS

Differences in peak subglottic pressure were moderate (d = 0.59) between expiratory and inspiratory groups, large between inspiratory and control groups (d = 1.32), and large between expiratory and control groups (d = 1.96). Differences in maximum phonation time were large (d = 1.26) between inspiratory and control groups, moderate (negative) between expiratory and inspiratory groups (d = -0.60), and moderate between expiratory and control groups (d = 0.72). Differences in peak sound pressure level were large (d = 1.27) between inspiratory and control groups, trivial between expiratory and inspiratory groups (d = -0.18), and large between expiratory and control groups (d = 1.10).

CONCLUSIONS

Inspiratory muscle training is effective in improving maximum phonation time, and expiratory muscle training is more effective for improving peak subglottic pressure, and peak sound pressure level in individuals with PD.

Putative Role of Respiratory Muscle Training to Improve Endurance Performance in Hypoxia: A Review

Respiratory/inspiratory muscle training (RMT/IMT) has been proposed to improve the endurance performance of athletes in normoxia. In recent years, due to the increased use of hypoxic training method among athletes, the RMT applicability has also been tested as a method to minimize adverse effects since hyperventilation may cause respiratory muscle fatigue during prolonged exercise in hypoxia. We performed a review in order to determine factors potentially affecting the change in endurance performance in hypoxia after RMT in healthy subjects. A comprehensive search was done in the electronic databases MEDLINE and Google Scholar including keywords: “RMT/IMT,” and/or “endurance performance,” and/or “altitude” and/or “hypoxia.” Seven appropriate studies were found until April 2018. Analysis of the studies showed that two RMT methods were used in the protocols: respiratory muscle endurance (RME) (isocapnic hyperpnea: commonly 10–30′, 3–5 d/week) in three of the seven studies, and respiratory muscle strength (RMS) (Powerbreathe device: commonly 2 × 30 reps at 50% MIP (maximal inspiratory pressure), 5–7 d/week) in the remaining four studies. The duration of the protocols ranged from 4 to 8 weeks, and it was found in synthesis that during exercise in hypoxia, RMT promoted (1) reduced respiratory muscle fatigue, (2) delayed respiratory muscle metaboreflex activation, (3) better maintenance of SaO₂ and blood flow to locomotor muscles. In general, no increases of maximal oxygen uptake (VO_2max) were described. Ventilatory function improvements (maximal inspiratory pressure) achieved by using RMT fostered the capacity to adapt to hypoxia and minimized the impact of respiratory stress during the acclimatization stage in comparison with placebo/sham. In conclusion, RMT was found to elicit general positive effects mainly on respiratory efficiency and breathing patterns, lower dyspneic perceptions and improved physical performance in conditions of hypoxia. Thus, this method is recommended to be used as a pre-exposure tool for strengthening respiratory muscles and minimizing the adverse effects caused by hypoxia related hyperventilation. Future studies will assess these effects in elite athletes.

The elevation training mask induces modest hypoxaemia but does not affect heart rate variability during cycling in healthy adults

This study examined the acute effects of the elevation training mask (ETM) on haemodynamics and heart rate variability (HRV) at rest, during cycling, and during recovery in healthy adults. Fifteen healthy male (N=9) and female (N=6) adults (27.0 ± 1.14 years) completed two trials with the mask (MASK) and without the mask (CON). The 40-minute cycling exercise protocol included 10-minute phases of (1) rest, (2) 50% of VO_2peak cycling, (3) 70% of VO_2peak cycling, and (4) recovery. Blood pressure and pulse oximetry saturation (S_PO₂) were measured at each phase. An Actiwave-Cardio ECG monitor (CamNtech, UK) was used to measure HRV variables including time and frequency domains. A greater response in systolic blood pressure (p=.035) was observed at rest while S_PO₂ (p=.033) was lower during high-intensity cycling (70% of VO_2peak) in the MASK trial. The HRV indices were not different between trials during cycling. However, heart rate (p=.047) was greater while inter-beat interval and sympathovagal balance (the ratio between low-frequency and high-frequency components; ln LF/HF, p=.01) were lower in the MASK than the CON trials during recovery. Wearing an ETM during high-intensity cycling (70% of VO_2peak) induces modest hypoxaemia. Although this device did not affect HRV changes during cycling, it seems to delay the cardiac-autonomic recovery from exercise. Healthy adults may be required to perform high-intensity exercise with an ETM to simulate a hypoxic environment, but future studies are needed to determine whether repeated exposure to this condition provides similar benefits as altitude training.

Respiratory Frequency during Exercise: The Neglected Physiological Measure

The use of wearable sensor technology for athlete training monitoring is growing exponentially, but some important measures and related wearable devices have received little attention so far. Respiratory frequency (f_R), for example, is emerging as a valuable measurement for training monitoring. Despite the availability of unobtrusive wearable devices measuring f_R with relatively good accuracy, f_R is not commonly monitored during training. Yet f_R is currently measured as a vital sign by multiparameter wearable devices in the military field, clinical settings, and occupational activities. When these devices have been used during exercise, f_R was used for limited applications like the estimation of the ventilatory threshold. However, more information can be gained from f_R. Unlike heart rate, V˙O₂, and blood lactate, f_R is strongly associated with perceived exertion during a variety of exercise paradigms, and under several experimental interventions affecting performance like muscle fatigue, glycogen depletion, heat exposure and hypoxia. This suggests that f_R is a strong marker of physical effort. Furthermore, unlike other physiological variables, f_R responds rapidly to variations in workload during high-intensity interval training (HIIT), with potential important implications for many sporting activities. This Perspective article aims to (i) present scientific evidence supporting the relevance of f_R for training monitoring; (ii) critically revise possible methodologies to measure f_R and the accuracy of currently available respiratory wearables; (iii) provide preliminary indication on how to analyze f_R data. This viewpoint is expected to advance the field of training monitoring and stimulate directions for future development of sports wearables.

Effects of Exercise on Cervical Angle and Respiratory Function in Smartphone Users

Objectives

The aim of this study was to determine whether exercises can change the cervical angle and respiratory function in smartphone users.

Methods

Thirty healthy volunteers were recruited. The subjects were randomly divided into an exercise group and a control group. All participants used a smartphone for 1 hour while maintaining a sitting posture. Then, each group performed their assigned activity. The exercise group performed two types of exercises and the control group maintained routine activities for 20 minutes. To investigate the changes in cervical angle and respiratory function, we measured the craniovertebral angle by using a spirometer.

Results

Statistically significant differences were noted in the craniovertebral angle, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, peak expiratory flow, maximal inspiratory pressure, and maximal expiratory pressure of the two groups (p < 0.05).

Conclusion

Our findings showed that proper exercise could be a good method of improving the cervical angle and respiratory function in smartphone users.

Efficacy of inspiratory muscle training as a practical and minimally intrusive technique to aid functional fitness among adults with obesity

OBJECTIVE

To examine the efficacy of inspiratory muscle training (IMT) as a non-intrusive and practical intervention to stimulate improved functional fitness in adults with obesity. As excess adiposity of the chest impedes the mechanics of breathing, targeted re-training of the inspiratory muscles may ameliorate sensations of breathlessness, improve physical performance and lead to greater engagement in physical activity.

METHODS

Sixty seven adults (BMI=36±6.5) were randomized into either an experimental (EXP: n=35) or placebo (PLA: n=32) group with both groups undertaking a 4-week IMT intervention, comprising daily use of a inspiratory resistance device set to 55% (EXP), or 10% (PLA) of maximum inspiratory effort.

RESULTS

Inspiratory muscle strength was significantly improved in EXP (19.1 cmH₂0 gain; P<0.01) but did not change in PLA. Additionally, the post training walking distance covered was significantly extended for EXP (P<0.01), but not for PLA. Bivariate analysis demonstrated a positive association between the change (%) of performance in the walking test and BMI (r=0.78; P<0.01) for EXP.

CONCLUSION

The findings from this study suggest IMT provides a practical, self-administered intervention for use in a home setting. This could be a useful strategy to improve the functional fitness of obese adults and perhaps lead to better preparedness for engagement in physical activity initiatives.

Effects of fast expiration exercises without pressure on the respiratory muscle strength of healthy subjects

[Purpose] The aim of this investigation was to determine the effects of 4 weeks of fast expiration exercises performed without pressure on respiratory muscle strength. [Subjects and Methods] Respiratory muscle strength of the training group that performed fast expiration exercises (n=12) was compared with that of a control group that performed no exercises (n=12). The fast expiration exercises were performed using a peak expiratory flow meter device and consisted of 20 fast expiration exercises performed 3 times per week for 4 weeks. Maximal expiratory and inspiratory pressures were evaluated as respiratory muscle strength using a spirometer pre- and post- intervention. [Results] There were significant increases in maximal expiratory pressure from 76.9 ± 29.1 to 96.1 ± 37.5 cmH₂O and maximal inspiratory pressure from 80.8 ± 36.6 to 95.3 ± 37.6 cmH₂O in the training group, but there was no significant difference in respiratory muscle strength between pre- and post-intervention in the control group. [Conclusion] Fast expiration exercises may be beneficial for increasing respiratory muscle strength. The findings of this study should be considered when prescribing a variation of the expiratory muscle strength training, as part of a pulmonary rehabilitation program.

Breathing exercises and inspiratory muscle training in heart failure

Breathing exercises (BE) and inspiratory muscle training (IMT) have been demonstrated to improve ventilation and ventilation-to-perfusion matching, and to improve exercise, functional performance, and many pathophysiologic manifestations of heart failure (HF). This article provides an extensive review of BE and IMT in patients with HF and identifies several key areas in need of further investigation, including the role of expiratory muscle training, IMT targeted at various locations of inspiration (early, mid, or late inspiration), and alteration of the ratio of inspiratory time to total breath time, all of which have substantial potential to improve many pathophysiologic manifestations of HF.

Functional outcomes associated with expiratory muscle strength training: narrative review

This review presents the available evidence for the effects of expiratory muscle strength training (EMST) with the use of a pressure threshold device. The investigators used computerized database searches for studies reporting the outcomes of pressure threshold EMST published after 1994. A total of 24 selected articles presented outcomes related but not limited to respiratory function, such as speech, swallow, voice, and cough function in persons with neurologic conditions such as Parkinson disease, multiple sclerosis, and Lance-Adams syndrome; in persons with respiratory diseases, such as chronic obstructive pulmonary disease; and in healthy young adults and sedentary and active elderly. Several studies demonstrated promising outcomes of EMST as a non-task-specific training for airway protection in persons with dysphagia secondary to neuromuscular impairments; however, further research is needed to confirm and generalize the reported findings.

Effects of inspiratory and expiratory muscle training in normal subjects

The present study aimed to clarify the effects of inspiratory muscle training (IMT) and expiratory muscle training (EMT) on ventilatory muscle strength, pulmonary function and responses during exercise testing. Young healthy women were randomly assigned to 3 groups: IMT (n=16); EMT (n=16); or untrained normal controls (NC, n=8). Subjects in the IMT and EMT groups trained for 15 minutes twice daily over 2 weeks at loads of 30% maximal inspiratory and expiratory muscle strength, respectively. Ventilatory muscle strength (maximal inspiratory and expiratory muscle strength; PImax and PEmax, respectively), pulmonary function and progressive exercise testing was performed. Both PImax and PEmax increased in the IMT group, and PEmax increased in the EMT group. Neither trained group demonstrated any change in pulmonary function or peak values during exercise testing. In the IMT group, exercise-induced increases in heart rate, oxygen uptake (VO2/kg) and rating of perceived exertion (RPE) decreased with training, as did increases in VO2/kg and RPE in the EMT group. The increased ventilatory muscle strength in both IMT and EMT groups might improve ventilatory efficacy during exercise, and increased inspiratory muscle strength might facilitate oxygen delivery through improved circulatory responses.

Respiratory muscle training on pulmonary and swallowing function in patients with Huntington's disease: a pilot randomised controlled trial

OBJECTIVE

To examine the effects of 4-month of respiratory muscle training on pulmonary and swallowing function, exercise capacity and dyspnoea in manifest patients with Huntington's disease.

DESIGN

A pilot randomised controlled trial.

SETTING

Home based training program.

PARTICIPANTS

Eighteen manifest Huntington's disease patients with a positive genetic test and clinically verified disease expression, were randomly assigned to control group (n=9) and training group (n=9).

INTERVENTION

Both groups received home-based inspiratory (5 sets of 5 repetitions) and expiratory (5 sets of 5 repetitions) muscle training 6 times a week for 4 months. The control group used a fixed resistance of 9 centimeters of water, and the training group used a progressively increased resistance from 30% to 75% of each patient's maximum respiratory pressure.

MAIN MEASURES

Spirometric indices, maximum inspiratory pressure, maximum expiratory pressure, six minutes walk test, dyspnoea, water-swallowing test and swallow quality of life questionnaire were assessed before, at 2 and 4 months after training.

RESULTS

The magnitude of increases in maximum inspiratory (d=2.9) and expiratory pressures (d=1.5), forced vital capacity (d=0.8), forced expiratory volume in 1 second (d=0.9) and peak expiratory flow (d=0.8) was substantially greater for the training group in comparison to the control group. Changes in swallowing function, dyspnoea and exercise capacity were small (d ≤ 0.5) for both groups without substantial differences between groups.

CONCLUSIONS

A home-based respiratory muscle training program appeared to be beneficial to improve pulmonary function in manifest Huntington's disease patients but provided small effects on swallowing function, dyspnoea and exercise capacity.

Effect of expiratory resistive loading in expiratory muscle strength training on orbicularis oris muscle activity

[Purpose] The purpose of this study was to elucidate the effect of expiratory resistive loading on orbicularis oris muscle activity. [Subjects] Subjects were 23 healthy individuals (11 males, mean age 25.5±4.3 years; 12 females, mean age 25.0±3.0 years). [Methods] Surface electromyography was performed to measure the activity of the orbicularis oris muscle during maximum lip closure and resistive loading at different expiratory pressures. Measurement was performed at 10%, 30%, 50%, and 100% of maximum expiratory pressure (MEP) for all subjects. The t-test was used to compare muscle activity between maximum lip closure and 100% MEP, and analysis of variance followed by multiple comparisons was used to compare the muscle activities observed at different expiratory pressures. [Results] No significant difference in muscle activity was observed between maximum lip closure and 100% MEP. Analysis of variance with multiple comparisons revealed significant differences among the different expiratory pressures. [Conclusion] Orbicularis oris muscle activity increased with increasing expiratory resistive loading.

Respiratory muscle training for respiratory deficits in neurodegenerative disorders: a systematic review

BACKGROUND

Studies of the impact of respiratory muscle training (RMT) on central neurodegenerative pathologies have been aimed at improving pulmonary function. However, there is no certainty about the effectiveness of RMT in patients affected by these groups of disorders. The purpose of this review was to assess the evidence regarding the efficacy of inspiratory muscle training (IMT) and expiratory muscle training (EMT) on respiratory function in patients with neurodegenerative disorders of the CNS.

METHODS

A comprehensive search from 1990 to September 2012 on MEDLINE, Physiotherapy Evidence Database (PEDro), PubMed, Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases was made. Studies reporting on IMT and EMT in patients with neurodegenerative diseases were included. The selected studies were abstracted using a standardized data collection instrument and were assessed by a quality checklist created and adapted from CONSORT (Consolidated Standards for Reporting Trials) and TREND (Transparent Reporting of Evaluation with Nonrandomized Designs).

RESULTS

Twenty-four studies were identified by the search strategy. Only 19 studies met the criteria for full review. Ten studies met all the inclusion criteria and were included in the final analysis. Of the 16 parameters present in the quality assessment checklist, only six were achieved for the studies analyzed.

CONCLUSIONS

There is some evidence that RMT improves a number of respiratory function parameters in patients with Parkinson disease and multiple sclerosis; however, the number of studies and their quality are not sufficient to conclude whether IMT or EMT is effective in improving respiratory function in patients with neurodegenerative disorders of the CNS.

Change in tongue morphology in response to expiratory resistance loading investigated by magnetic resonance imaging

[Purpose] The purpose of this study was to investigate the effect of expiratory resistance load on the tongue area encompassing the suprahyoid and genioglossus muscles. [Subjects] The subjects were 30 healthy individuals (15 males, 15 females, mean age: 28.9 years). [Methods] Magnetic resonance imaging was used to investigate morphological changes in response to resistive expiratory pressure loading in the area encompassing the suprahyoid and genioglossus muscles. Images were taken when water pressure was sustained at 0%, 10%, 30%, and 50% of maximum resistive expiratory pressure. We then measured tongue area using image analysis software, and the morphological changes were analyzed using repeated measures analysis of variance followed by post hoc comparisons. [Results] A significant change in the tongue area was detected in both sexes upon loading. Multiple comparison analysis revealed further significant differences in tongue area as well as changes in tongue area in response to the different expiratory pressures. [Conclusion] The findings demonstrate that higher expiratory pressure facilitates greater reduction in tongue area.

Four weeks of inspiratory muscle training improves self-paced walking performance in overweight and obese adults: a randomised controlled trial

Objective. To examine whether a programme of inspiratory muscle training (IMT) improves accumulative distance of self-paced walking in overweight and obese adults. Methods. A total of 15 overweight and obese adults were randomized into experimental (EXP: n = 8) and placebo (PLA: n = 7) groups. Lung function, inspiratory muscle performance, 6-minute walking test, and predicted [Formula: see text]O(2) max were assessed prior to and following the 4-week IMT intervention. Both groups performed 30 inspiratory breaths, twice daily using a proprietary inspiratory resistance device set to 55% of baseline maximal effort (EXP), or performing the same inspiratory training procedure at the minimum resistive setting (PLA). Results. Lung function was unchanged in both groups after-training; however inspiratory muscle strength was significantly improved in EXP (19 ± 25.2 cm H(2)O gain; P < 0.01) but did not significantly change in PLA. Additionally, the posttraining distance covered in the 6-minute walking test was significantly extended for EXP (62.5 ± 37.7 m gain; P < 0.01), but not for PLA. A positive association was observed between the change (%) of performance gain in the 6-minute walking test and body mass index (r = 0.736; P < 0.05) for EXP. Conclusion. The present study suggests that IMT provides a practical, minimally intrusive intervention to significantly augment both inspiratory muscle performance and walking distance covered by overweight and obese adults in a clinically relevant 6-minute walk test. This indicates that IMT may provide a useful priming (preparatory) strategy prior to entry in a physical training programme for overweight and obese adults.

Pilates: how does it work and who needs it?

Pilates uses a combination of approximately 50 simple, repetitive exercises to create muscular exertion. Advocates of this system of exercise claim that exercises can be adapted to provide either gentle strength training for rehabilitation or a strenuous workout vigorous enough to challenge skilled athletes. The exercises are designed to increase muscle strength and endurance, as well as flexibility and to improve posture and balance. There is cautious support for the effectiveness of Pilates in improving flexibility, abdominal and lumbo-pelvic stability and muscular activity. Stronger support cannot be given at this point in time primarily due to the limited number of studies and the lack of sound methodology in the published research. However, current research does indicate that there may be applications for this type of intervention in certain clinical populations that are worthy of continued investigation.

Inspiratory Muscle Training and Endurance: A Central Metabolic Control Perspective

The efficacy of inspiratory muscle training (IMT) has been the subject of considerable controversy in terms of whether it is beneficial to endurance athletes and because a convincing physiological rationale has not been identified to explain its mechanism of action. Early studies suggested that IMT was an ineffectual intervention for gains in either maximal aerobic power or endurance-specific performance. More rigorous recent research supports the observation that maximal aerobic power is not receptive to IMT; however, closer evaluation of both early and contemporary research indicates that responses to endurance-specific performance tests are sensitive to IMT. As the aim of endurance training is to improve endurance performance rather than maximal aerobic power, it is plausible that IMT may be useful in specific performance-related circumstances. Performance adaptations following IMT appear to be connected with post training reports of attenuated effort sensations, but this common observation has tended to be overlooked by researchers in preference for a reductionist explanation. This commentary examines the pertinent research and practical performance implications of IMT from the holistic perspective of complex central metabolic control.

The effects of respiratory-muscle training on exercise in older women

This research examined the effects of respiratory-muscle (RM) training on RM function and exercise performance in older women. Twenty-six women (60-69 yr of age) were assessed for spirometry, RM strength (maximal inspiratory and expiratory pressure), inspiratory-muscle endurance, and walking performance to a perceived exertion rating of "hard." They were randomly allocated to a threshold RM training group (RMT) or a nonexercising control group (CON) for 8 wk.After training, the 22% (inspiratory) and 30% (expiratory) improvements in RM strength in the RMT group were significantly higher than in the CON group (p < .05). The RMT group also displayed several significant performance improvements, including improved within-group treadmill performance time (12%) and reductions in submaximal heart rate (5%), percentage of maximum voluntary ventilation (16%), and perceived exertion for breathing (8%). RM training appears to improve RM function in older women. Furthermore, these improvements appear to be related to improved submaximal exercise performance.

Treatment Outcomes for Professional Voice Users

Professional voice users comprise 25% to 35% of the U.S. working population. Their voice problems may interfere with job performance and impact costs for both employers and employees. The purpose of this study was to examine treatment outcomes of two specific rehabilitation programs for a group of professional voice users. Eighteen professional voice users participated in this study; half had complaints of throat pain or vocal fatigue (Dysphonia Group), and half were found to have benign vocal fold lesions (Lesion Group). One group received 5 weeks of expiratory muscle strength training followed by six sessions of traditional voice therapy. Treatment order was reversed for the second group. The study was designed as a repeated measures study with independent variables of treatment order, laryngeal diagnosis (lesion vs non-lesion), gender, and time. Dependent variables included maximum expiratory pressure (MEP), Voice Handicap Index (VHI) score, Vocal Rating Scale (VRS) score, Voice Effort Scale score, phonetogram measures, subglottal pressures, and acoustic and perceptual measures. Results showed significant improvements in MEP, VHI scores, and VRS scores, subglottal pressure for loud intensity, phonetogram area, and dynamic range. No significant difference was found between laryngeal diagnosis groups. A significant difference was not observed for treatment order. It was concluded that the combined treatment was responsible for the improvements observed. The results indicate that a combined modality treatment may be successful in the remediation of vocal problems for professional voice users.

Expiratory Muscle Strength Training

Purpose. This study investigated the effect of expiratory muscle strength training (EMST) on voice production, dysarthria, and voice-related quality-of-life issues in persons with multiple sclerosis (PwMS). It was hypothesized that PwMS would have improved voice production and reduced voice-related quality-of-life issues following EMST. Participants and Methods. Seventeen participants with MS and 14 healthy (H) controls completed 8 weeks of EMST, followed by 4 weeks of no training. Analyzed outcomes as a function of EMST were maximal expiratory pressure (MEP), sustained vowel prolongation (SVP), words per minute (WPM) measured from connected speech, and quality-of-life indices related to the presence of the dysarthria and dysphonia. Results. PwMS had lower MEPs, shorter SVP, and less WPM than the controls prior to training. Following EMST, both groups had significant improvement in MEPs that stayed above baseline after training halted. EMST did not improve voice production or voice-related quality of life for PwMS. Conclusion. Respiratory muscle weakness is present in PwMS having mild- to moderate-level disability. EMST improved expiratory muscle strength but did not statistically change objective and subjective components of voice/speech production in PwMS.