Expiratory Muscle Strength Research Articles

Short-term expiratory muscle strength training attenuates sleep apnea and improves sleep quality in patients with obstructive sleep apnea

This study investigated the effects of 5 weeks of expiratory muscle strength training (EMST) on sleep apnea, sleep quality, and respiratory muscle strength in patients with different levels of obstructive sleep apnea (OSA). Twenty-five outpatients who received a diagnosis of OSA participated in the study and were assigned to either the EMST group (n=13) or control group (CTRL, n=12). The training intensity for the EMST group was 75% of the maximum static expiratory (PEmax) score (5days/week). The PEmax, apnea–hypoapnea index (AHI), Epworth Sleepiness Scale (ESS), and Pittsburgh Sleep Quality Index (PSQI) scores were evaluated before and after the treatment. EMST improved the scores for AHI (−40%), PEmax (+68%), and PSQI (−28%) and reduced the PSQI scores of the moderate OSA subgroup but not the mild OSA subgroup. The percent changes (Δ%) in the AHI and PEmax scores of participants with OSA were negatively correlated. We demonstrated that EMST effectively improved sleep apnea, sleep quality, and expiratory muscle strength in participants with OSA. Participants with moderate OSA exhibited greater improvement than did those with mild OSA, and the improvement in PEmax scores was correlated with a decrease in sleep apnea.

Diaphragmatic dysfunction in SEPN1-related myopathy

SEPN1-related myopathy (SEPN1-RM) is characterized by predominant axial muscle weakness, early scoliosis, rigid spine and severe respiratory insufficiency. The aim of the study was to characterize the mechanisms of respiratory dysfunction in SEPN1-RM patients. Breathing pattern and respiratory muscle strength were measured by means of esophageal (Pes) and gastric (Pgas) pressures. Seven patients aged 7–55 years (1 adult) at first respiratory muscle test were studied. Five patients were treated by nocturnal noninvasive ventilation (NIV) ≥ 4 months. Mean ΔPes was within normality during tidal breathing, but the ΔPgas/ΔPes index indicated an increased contribution of the rib cage and expiratory muscles, as compared to the diaphragm, in the pediatric patients and bilateral diaphragmatic paralysis in the adult patient. Forced vital capacity (FVC) was reduced in all patients (52 ± 19%pr) with mean FVC seated-supine drop of 24 ± 7%. Global inspiratory muscle and diaphragmatic strengths were moderately reduced in 2 patients, highly reduced in 4 patients and severely reduced in the adult patient. Expiratory muscle strength was moderately reduced in 6 patients and severely reduced in the adult patient. FVC and respiratory muscle strength remained stable in 2 patients treated by nocturnal NIV within a 3-year follow-up. This study confirms that diaphragmatic dysfunction is a characteristic feature of SEPN1-RM and NIV may stabilize the decline in respiratory muscle strength.

Diaphragmatic mobility: relationship with lung function, respiratory muscle strength, dyspnea, and physical activity in daily life in patients with COPD.

ABSTRACTObjective: To evaluate diaphragmatic mobility in relation to lung function, respiratory muscle strength, dyspnea, and physical activity in daily life (PADL) in patients with COPD. Methods: We included 25 patients with COPD, classified according to the Global Initiative for Chronic Obstructive Lung Disease criteria, and 25 healthy individuals. For all of the participants, the following were evaluated: anthropometric variables, spirometric parameters, respiratory muscle strength, diaphragmatic mobility (by X-ray), PADL, and the perception of dyspnea. Results: In the COPD group, diaphragmatic mobility was found to correlate with lung function variables, inspiratory muscle strength, and the perception of dyspnea, whereas it did not correlate with expiratory muscle strength or PADL. Conclusions: In patients with COPD, diaphragmatic mobility seems to be associated with airway obstruction and lung hyperinflation, as well as with ventilatory capacity and the perception of dyspnea, although not with PADL.

Expiratory muscle strength training evaluated with simultaneous high-resolution manometry and electromyography.

To examine feasibility of a simultaneous high-resolution pharyngeal manometry (HRM) and electromyography (EMG) experimental paradigm to detect swallowing-related patterns of palatal, laryngeal, and pharyngeal muscle activity during expiratory training. Technical report. Simultaneous HRM, surface submental, and intramuscular EMG were acquired in two healthy participants during five tasks: 10-cc water swallow, maximum expiratory pressure (MEP) testing, and expiratory muscle strength training (EMST) at three pressure levels (sham, 50%, and 75% MEP). Experimental conditions were feasible. Velopharyngeal closing pressure, palate EMG activity, and pharyngeal EMG activity increased as expiratory load increased. In contrast, thyroarytenoid EMG activity was low during the expiratory task, consistent with glottic opening during exhalation. Submental EMG patterns were more variable during expiratory tasks. Intraluminal air pressures recorded with HRM were correlated with measured expiratory pressures and target valve-opening pressures of the EMST device. Results suggest that a simultaneous HRM/EMG/EMST paradigm may be used to detect previously unquantified swallowing-related muscle activity during EMST, particularly in the palate and pharynx. Our approach and initial findings will be helpful to guide future hypothesis-driven studies and may enable investigators to evaluate other muscle groups active during these tasks. Defining mechanisms of action is a critical next step toward refining therapeutic algorithms using EMST and other targeted treatments for populations with dysphagia and airway disorders. 4. Laryngoscope, 127:797-804, 2017.

Respiratory muscle strength of patients with esophagus and stomach neoplasms

Abstract Introduction: In cancer patients, the reduced food intake causes weight loss and promotes protein-calorie malnutrition. This results in loss of lean body mass, which affects both skeletal muscles and respiratory muscles. Objective: Evaluate and compare the respiratory muscle strength of patients with esophageal and stomach neoplasia during the preoperative period. Methods: This is a cross-sectional study carried out with 24 patients of both genders hospitalized in a teaching hospital. They underwent a physical therapy evaluation composed of anthropometric data and measurement of respiratory muscle strength through manovacuometry. Paired and unpaired t-tests were used to compare the values obtained with the predicted equations. Results: Regarding the disease prevalence, 66.66%(16) of the individuals had stomach neoplasm and 33.33%(8) esophageal neoplasm. Of the patients with esophageal neoplasm, 100% were men with a mean age of 63 ± 9.16 years. Of those with stomach neoplasm, 68.75% were men with a mean age of 69.36 ± 10.92 years. Female patients with stomach neoplasm had significantly higher BMI (p = 0.01) than male patients, and they were classified as overweight. Both neoplasms had significantly lower real values (p ≤ 0.05) than predicted values at the maximal expiratory pressure. Conclusion: Patients with esophageal and stomach neoplasms in the preoperative period present reduction in the expiratory muscle strength. There were no statistically significant differences, when we compared the maximum respiratory pressures between the two types of neoplasms investigated.

Mechanisms for Successful Rehabilitation of Cough in Parkinson's Disease Using Expiratory Muscle Strength Training

Rehabilitation of cough is now moving under the purview of speech-language pathology as our understanding of the relationship between disorders of cough and swallow increases. The purpose of this review is to provide a guide in understanding the mechanisms of weak or disordered cough in Parkinson's disease, and mechanisms for why expiratory muscle strength training is an effective therapy. Additionally, this review provides resources for performing clinical evaluations of maximum expiratory pressure and dosage information for expiratory muscle strength training.

The effect of expiratory muscle strength training on the oral and respiratory functions of community-dwelling older people: An analysis using the swallowing, oral, phonatory, and respiratory muscle function indices.

This study was performed to determine the effects of expiratory muscle strength training (EMST) on the oral and respiratory functions of community-dwelling older people. Older people using a visiting-rehabilitation center were divided into an intervention group of 31 subjects and a control group of 15 subjects. Those in the intervention group were assigned home training for 8 weeks, which included 5 sets of 5 breaths per day with a 75% load of the maximum expiratory pressure using an EMST device. The outcome indices included (1) oral functions, evaluated by the cumulative time spent swallowing three times and the maximum phonation time (MPT) and (2) respiratory functions, evaluated by the maximum expiratory pressure and maximum inspiratory pressure (MEP/MIP). An independent t-test and paired t-test were used to analyze the data. The cumulative time spent swallowing three times was lower in the intervention group than in the control group. This difference remained significant even after adjusting for sex, age, and baseline values. The MPT was 2.1 seconds higher than baseline in the intervention group but 0.4 seconds lower than baseline in the control group. An average increase of 5.7 cmH2O in the PEmax was observed in the intervention group compared with an average decrease of 4.6 cmH2O in the control group, indicating a significant difference. These results suggest that EMST improves the oral and respiratory functions of community elderly subjects. This may be explained by the fact that the pathway for swallowing is partially shared with that for phonation, which contributes to a shortened swallowing time by repeated suprahyoid muscle contractions.

Effects of expiratory muscle strength training on swallowing function in acute stroke patients with dysphagia.

[Purpose] This study was conducted to identify the effects of expiratory muscle strength training on swallowing function in acute stroke patients with dysphagia. [Subjects and Methods] A total of 18 stroke patients with dysphagia were enrolled in the study. All participants were randomly assigned to either an experimental group (n=9) or a control group (n=9). All participants performed traditional-swallowing rehabilitation therapy in 30-minute sessions five times a week for four weeks; however, only the experimental group received expiratory muscle strength training. [Results] Both groups showed significant improvements after mediation. When compared with the control group, the functional dysphagia scale, vallecular residue, and penetration-aspiration scale were significantly improved in the experimental group. [Conclusion] Expiratory muscle strength training is an effective intervention for impaired swallowing function in acute strike patients with dysphagia.

Comparison of abdominal muscle activity and peak expiratory flow between forced vital capacity and fast expiration exercise.

[Purpose] The purpose of this investigation was to compare the activities of the abdominal muscles and peak expiratory flow between forced vital capacity and fast expiration exercise. [Subjects and Methods] Fifteen healthy male participated in this study. Peak expiratory flow and electromyographic activities of the rectus abdominis, external oblique, and internal oblique/transversus abdominis muscles were measured during forced vital capacity and fast expiration exercise and then peak amplitude and its appearance time were obtained. [Results] Peak expiratory flow values were significantly higher during fast expiration exercise than during forced vital capacity. The internal oblique/transversus abdominis muscles showed significantly higher peak amplitude during fast expiration exercise than during forced vital capacity. However, there were no significant differences between forced vital capacity and fast expiration exercise in the rectus abdominis and external oblique muscles. There was no difference in the appearance time of the peak amplitude between forced vital capacity and fast expiration exercise in any muscle. [Conclusion] Fast expiration exercise might be beneficial for increasing expiratory speed and neuromuscular activation of the internal oblique/transversus abdominis muscles compared to forced vital capacity. These findings could be considered when recommending a variation of expiratory muscle strength training as part of pulmonary rehabilitation programs.

Electromyographic activities of the abdominal muscles during 30% and 75% of maximum expiratory pressure

The aim of this study was to quantify the activities of the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles during 30% and 75% of maximum expiratory pressure (PE max).Fifteen healthy male university students participated in this study. Electromyographic (EMG) activities of the RA, EO, and IO muscles were measured during 30% and 75% of PE max and then normalized relative to maximum voluntary contractions (%MVC).All muscles during 75% of PE max showed significantly higher %MVC compared to that during 30% of PE max (P < 0.01). The EO and IO muscles showed significantly higher %MVC compared to the RA muscle during 30% and 75% of PE max (P < 0.05).Muscle endurance and strength induced by expiratory muscle strength training might be different in each abdominal muscle.

Abstract P119: Association Between Inspiratory Muscle Strength and Sympathetic Cardiac Modulation and Baroreflex in Patients With End Stage Renal Disease Undergoing Hemodialysis

Introduction: Patients with end-stage renal disease (ESRD) are susceptible to development of autonomic dysfunction and have metabolic and muscular changes which are associated with decreased functional capacity. Objectives: To evaluate respiratory muscle strength and cardiac autonomic modulation in ESRD patients undergoing hemodialysis. Methods: ESRD patients undergoing hemodialysis (n= 9, mean age 46.2±14.1 years) and healthy controls (n =7, mean age 44.6±14.6 years) were assessed. Non–invasive curves of blood pressure were recorded continuously (Finometer ®) for 10 minutes. The heart rate variability was estimated in the time and frequency domain. Inspiratory and expiratory maximal pressures (IPmax and EPmax) were quantified using a pressure transducer. Mann-Whitney and Spearman tests were used. The results were expressed as mean ± SD. Results: Regarding respiratory muscle strength, ESRD patients had lower inspiratory (IPmax: 79.1±25.0 vs 121.3±24.3cmH 2 O, p=0.03) and expiratory muscle strength (EPmax 92.8±23.1 vs 153.8±23.5cmH 2 O, p=0.01) then healthy controls. ESRD patients presented lower heart rate variability than healthy controls (SDNN: 19.2±4.0 vs 52.6±18.8ms, p=0.000) and lower RMSSD, an index of vagal modulation (11.8±5.2 vs 46.1±20.4ms, p=0.000). Regarding frequency domain indexes, ESRD patients presented higher low-frequency component (LFnu= 68.9±11.9 vs 47.3± 2.8, p=0.008), lower high-frequency component (HFnu= 31.1±11.9 vs 52.7±12.8, p=0.008) and higher sympathovagal balance (LF/HF: (LF/HF= 3.1±1.3 vs 1.1±0.5, p=0.005) when compared to controls. Furthermore baroreflex sensitivity was reduced in ESRD patients (alfa index: 3.6±1.6 vs 11.7±4.4ms/mmHg, p=0.002). In ESRD patients the IPmax was significantly associated with LF (r=-0.813, p=0.014) and with alfa index (r=-0.900, p=0.037). Conclusion: ESRD patients undergoing hemodialysis presented reduced inspiratory muscle strength, increased sympathetic modulation and reduced cardiac vagal modulation and impaired baroreflex sensitivity. In these patients inspiratory muscle strength was associated with sympathetic cardiac modulation and baroreflex.

Respiratory training in an individual with amyotrophic lateral sclerosis.

We examined the impact of expiratory muscle strength training on maximum expiratory pressure, cough spirometry, and disease progression in a 71‐year‐old male with amyotrophic lateral sclerosis. Maximum expiratory pressure declined 9% over an 8‐week sham training period, but subsequently improved by 102% following 8 weeks of expiratory muscle strength training. Improvements in cough spirometry and mitigated disease progression were also observed post expiratory muscle strength training. Improvements in maximum expiratory pressures were maintained 6 months following expiratory muscle strength training and were 79% higher than baseline data obtained 301 days prior. In this spinal‐onset amyotrophic lateral sclerosis patient, respiratory training improved subglottic air pressure generation and sequential cough generation.

Effects of Aerobic Exercise Applied Early After Coronary Artery Bypass Grafting on Pulmonary Function, Respiratory Muscle Strength, and Functional Capacity: A Randomized Controlled Trial.

Physical activity is beneficial in several clinical situations and recommended for patients with ischemic heart disease, as well as for those undergoing cardiac surgery. In a randomized controlled trial, 34 patients underwent coronary artery bypass grafting. A randomized control group (n = 15) submitted to conventional physiotherapy. The intervention group (n = 19) received the same protocol plus additional aerobic exercise with cycle ergometer. Pulmonary function by spirometry, respiratory muscle strength by manovacuometry, and functional capacity through 6-minute walking test was assessed before surgery and at hospital discharge. There was significant reduction in pulmonary function in both groups. In both groups, inspiratory muscle strength was maintained while expiratory muscle strength significantly decreased. Functional capacity was maintained in the intervention group (364.5 [324.5 to 428] vs. 348 [300.7 to 413.7] meters, P = .06), but it decreased significantly in control group patients (320 [288.5 to 393.0] vs. 292 [237.0 to 336.0] meters, P = .01). A significant difference in functional capacity was also found in intergroup analyses at hospital discharge (P = .03). Aerobic exercise applied early on coronary artery bypass grafting patients may promote maintenance of functional capacity, with no impact on pulmonary function and respiratory muscle strength when compared with conventional physiotherapy.

Effect of conventional physical therapy and Pilates in functionality, respiratory muscle strength and ability to exercise in hospitalized chronic renal patients: a randomized controlled trial

Objective: To compare the effect of conventional physical therapy and Pilates on function, restoration, and exercise ability in hospitalized chronic renal patients. Methods: A total of 56 inpatients were randomized into two groups: Conventional physical therapy and Pilates. The primary outcomes were functionality (Barthel Index), respiratory muscle strength (manovacuometry), and ability to exercise (step test) evaluated in the following periods: preintervention, after the 5th session, and after the 10th session or at discharge. Three months after randomization, the Barthel Index was applied over the phone. At the end of the 10 sessions or at discharge, the length of hospital stay was calculated and the level of satisfaction with physical therapy care was assessed (MedRisk). Linear mixed models were used for the primary outcomes and the Student’s t-test was used for length of stay and satisfaction. Results: There was no significant between-group difference in functionality (MD −1.3; 95% CI −2.8 to 5.4), inspiratory and expiratory muscle strength (MD −1.3; 95% CI −7.3 to 4.5/MD −4.5; 95% CI −0.7 to 9.7, respectively), performance in the step test (MD −3.3; 95% CI −6.2 to 12.8), patient satisfaction with physical therapy care (MD −2.0; 95% CI −5.1 to 9.1), and length of stay (MD 4.5; 95% CI −15.9 to 6.8). Conclusion: Both interventions, conventional physical therapy and Pilates, showed improvements and there is no difference between them. Therefore both can be used in chronic renal patients.

Dysphagia in Parkinson's Disease: Pathophysiology, Diagnosisand Therapy

Oropharyngeal and esophageal dysphagia are a frequent, but seldom diagnosed symptom of Parkinson's disease (PD). More than 80 % of patients with PD develop dysphagia during the course of their disease leading to a reduced quality of life, complicated medication intake, malnutrition and aspiration pneumonia, which is a major cause of death inPD. The underlying pathophysiology is poorly understood. Impaired dopaminergic and non-dopaminergic mechanisms of the cortical swallowing network as well as peripheral neuromuscular involvement have been suggested to contribute to its multifactorial genesis. Diagnostic screening methods include PD-specific questionnaires and a modified water test. Fiber optic endoscopic evaluation of swallowing (FEES) and videofluoroscopic swallowing study (VFSS), which complement each other, are the gold standard forevaluation of PD-related dysphagia. For evaluation of esophageal dysphagia, the high-resolution manometry (HRM) may be a helpful tool. In addition to dysphagia-specific treatment by speech and language therapists (SLTs), optimized dopaminergic medication is a meaningful therapeutic option. A promising novel method is intensive training of expiratory muscle strength (EMST). Deep brain stimulation does not seem to have a clinically relevant effect on swallowing function in PD.

Effect of expiratory muscle strength training on swallowing-related muscle strength in community-dwelling elderly individuals: a randomized controlled trial.

This study aimed to investigate the effect of expiratory muscle strength training (EMST) on swallowing-related muscle strength in community-dwelling elderly individuals. Expiratory muscle strength training is an intervention for patients with oropharyngeal dysphagia. This training is associated with respiration, coughing, speech and swallowing, and its effectiveness has been proven in previous studies. However, the effects of EMST on elderly individuals and evidence are still lacking. This study included 24 community-dwelling senior citizens aged ≥65 years (12 men and 12 women). The experimental group trained at the 70% threshold value of the maximum expiratory pressure using an EMST device 5 days per week for 4 weeks and comprised five sets of five breaths through the device for 25 breaths per day. The placebo group trained with a resistance-free sham device. Post-intervention, muscle strength of the bilateral buccinator and the orbicularis oris muscles (OOM) was measured using the Iowa Oral Performance Instrument. Surface electromyography was used to measure activation of the suprahyoid muscles (SM). After intervention, the strength of the buccinator and the OOM in the experimental group showed statistically significant improvement. There was also statistically significant activation of the SM. In the placebo group, the strength of the orbicularis oris muscle alone improved. No statistically significant differences between groups were found for the strength of the buccinator and the OOM and the activation of the SM. EMST had a positive effect on swallowing-related muscle strength in elderly participants.

Effects of Expiratory Muscle Strength Training on Lung Function and Musical Performance in Collegiate Wind Instrumentalists

Expiratory muscle strength training (EMST) has been associated with increased maximum expiratory pressure (MEP). Because wind instrumentalists depend on sufficient pressure production for optimal musical performance, it is possible that EMST might improve musical performance in this population. The purpose of this study was to determine if 4 weeks of EMST would improve instrumental performance in relation to MEP in college-level wind instrumentalists. All participants (N=19) were pre-tested for MEP (inH 2 O) and musical performance measures of loudness (dB) and duration of play (sec) on various pitches. Participants were then divided into groups matched by MEP, gender, and instrument. The experimental group (n=12) trained 4 times/week for 4 weeks at 75% MEP. Following training, MEP increased significantly in the experimental group (pre: 49.50±14.41; post: 83.17±22.47 inH 2 O) compared to the control group (pre: 50.29±7.76; post: 53.14±11.89 inH 2 O, p< 0.0001). There were no significant musical performance improvements as measured following training, but results suggest that EMST may be a viable option for instrumental training. Future research might build upon this study design to better assess the effects of EMST on musical performance in wind instrumentalists by considering alternate definitions for musical performance and by assessing specific instruments separately.

Rehabilitation of Swallowing and Cough Functions Following Stroke: An Expiratory Muscle Strength Training Trial

ObjectiveTo determine the effect of expiratory muscle strength training (EMST) on both cough and swallow function in stroke patients. DesignProspective pre-post intervention trial with 1 participant group. SettingTwo outpatient rehabilitation clinics. ParticipantsAdults (N=14) with a history of ischemic stroke in the preceding 3 to 24 months. InterventionEMST. The training program was completed at home and consisted of 25 repetitions per day, 5 days per week, for 5 weeks. Main Outcome MeasuresBaseline and posttraining measures were maximum expiratory pressure, voluntary cough airflows, reflex cough challenge to 200μmol/L of capsaicin, sensory perception of urge to cough, and fluoroscopic swallow evaluation. Repeated measures and 1-way analyses of variance were used to determine significant differences pre- and posttraining. ResultsMaximum expiratory pressure increased in all participants by an average of 30cmH2O posttraining. At baseline, all participants demonstrated a blunted reflex cough response to 200μmol/L of capsaicin. After 5 weeks of training, measures of urge to cough and cough effectiveness increased for reflex cough; however, voluntary cough effectiveness did not increase. Swallow function was minimally impaired at baseline, and there were no significant changes in the measures of swallow function posttraining. ConclusionsEMST improves expiratory muscle strength, reflex cough strength, and urge to cough. Voluntary cough and swallow measures were not significantly different posttraining. It may be that stroke patients benefit from the training for upregulation of reflex cough and thus improved airway protection.

Impact of expiratory strength training in amyotrophic lateral sclerosis.

We evaluated the feasibility and impact of expiratory muscle strength training (EMST) on respiratory and bulbar function in persons with amyotrophic lateral sclerosis (ALS). Twenty-five ALS patients participated in this delayed intervention open-label clinical trial. Following a lead-in period, patients completed a 5-week EMST protocol. Outcome measures included: maximum expiratory pressure (MEP); physiologic measures of swallow and cough; and penetration-aspiration scale (PAS) scores. Of participants who entered the active phase of the study (n = 15), EMST was well tolerated and led to significant increases in MEPs and maximum hyoid displacement during swallowing post-EMST (P < 0.05). No significant differences were observed for PAS scores or cough spirometry measures. EMST was feasible and well tolerated in this small cohort of ALS patients and led to improvements in expiratory force-generating pressures and swallow kinematics. Further investigation is warranted to confirm these preliminary findings. Muscle Nerve 54: 48-53, 2016.

Whistle and cough pressures in children with neuromuscular disorders

RationaleExpiratory muscle strength is a determinant of cough function. Maximal static expiratory pressure (PEmax) manoeuvres are widely used but are limited by patient motivation and technique. The study hypothesized that whistle mouth (PmW) and cough gastric (PgasCough) pressures might provide additional tests of expiratory muscle strength in children and young adults with neuromuscular disease (NMD). MethodsWe retrospectively reviewed the data of lung function and respiratory muscle tests of all the patients with NMD followed in our centre between November 2001 and December 2013. PmW and PgasCough were compared to other common tests. ResultsThree hundred and four respiratory evaluations were performed in 143 patients, aged 3–29 years old. Seventy-two patients had 2 to 8 evaluations. Median [interquartiles] PEmax (38 [28–54] cmH2O) did not differ significantly from PgasCough (45 [30–60] cmH2O) and both were significantly greater than PmW (30 [19–44] cmH2O). Significant good correlations were observed between all the expiratory muscle parameters. The best correlation was observed between PEmax and PmW (r = 0.812, p < 0.001). Moreover, good correlations were found between the percentage of predicted forced vital capacity and PmW (r = 0.619, p < 0.001) and PgasCough (r = 0.568, p < 0.001). Concerning the whistle test, the non-invasive measurement highly correlated with invasive measurements. ConclusionsPmW and PgasCough are simple and valuable tests to assess expiratory muscle strength in children and young adults with NMD. These tests are particularly useful in children having difficulties to perform PEmax manoeuvre. They have the great advantage of their simplicity, but PgasCough is limited by its invasiveness.