Differences In Respiratory Muscle Strength Research Articles

Reliability and Minimal Detectable Change for Respiratory Muscle Strength Measures in Individuals With Multiple Sclerosis.

The test-retest reliability and minimal detectable changes (MDCs) for respiratory muscle strength measures have not been determined in individuals with multiple sclerosis (MS). This study determined the test-retest reliability and MDCs for specific respiratory muscle strength measures, as well as their associations with health-related quality of life (HRQoL), disability, dyspnea, and physical activity level measures in this population. In addition, the study examined differences in respiratory muscle strength between different degrees of disability. Sixty-one individuals with MS attended 2 appointments separated by 7 to 10 days. Respiratory muscle strength was evaluated by maximal inspiratory and expiratory pressures (MIP/MEP), HRQoL by EuroQol-5D-5L (index and visual analog scale [EQ-VAS]), disability by the Expanded Disability Status Scale, dyspnea by the Medical Research Council scale, and physical activity levels by the International Physical Activity Questionnaire. Respiratory muscle strength measures had excellent test-retest reliability (ICC ≥ 0.92). The MDC for MIP is 15.42 cmH 2 O and for MEP is 17.84 cmH 2 O. Participants with higher respiratory muscle strength (MIP/MEP cmH 2 O and percentage of predicted values) had higher HRQoL ( r = 0.54-0.62, P < 0.01, EQ-5D-5L index; r = 0.30-0.42, P < 0.05, EQ-VAS); those with higher expiratory muscle strength (cmH 2 O and percentage of predicted values) had lower levels of disability ( r ≤ -0.66) and dyspnea ( r ≤ -0.61). There were differences in respiratory muscle strength between different degrees of disability ( P < 0.01; d ≥ 0.73). Respiratory muscle strength measures provide excellent test-retest reliability in individuals with MS. MDCs can be interpreted and applied in the clinical setting. Low respiratory muscle strength can contribute to a poor HRQoL; specifically, expiratory muscle strength appears to have the strongest influence on disability status and dyspnea.

Respiratory Muscle Strength in Brazilian Adolescents: Impact of Body Composition

(1) Introduction: Studies on respiratory muscle strength (RMS) in adolescents are controversial. Few studies so far have investigated respiratory muscle strength in Brazilian adolescents and the impact of body composition on it. (2) Objective: to evaluate the respiratory muscle strength of Brazilian adolescents and compare this with nationally and internationally predicted normality values. (3) Method: A cross-sectional study (CAEE: 34634414.5.0000.5479) was carried out with 98 adolescents, where both sexes were divided into four groups: eutrophic (n = 44); overweight (n = 15), obese (n = 25), and severely obese (n = 14). All were submitted to an anthropometric assessment, body composition analysis and manovacuometry. To interpret the results, Analysis of Variance (ANOVA) with Turkey’s post hoc test was used. The Kruskal–Wallis test and Friedman’s post hoc test were used to compare the observed vs. proposed results. A p-value &lt; 0.05 was considered statistically significant. (4) Results: There were no differences among the groups for maximal inspiratory (MIP) and expiratory (MEP) pressures. However, when considering the total sample, we could say that RMS was higher among boys, and there were no significant differences in RMS in relation to the maturational stage. The values obtained for MIP were lower than those suggested for the national equation and higher than those proposed for the international equation. Similarly, the values obtained for MEP were lower than those suggested for the national and international equation. (5) Conclusions: RMS was similar in adolescents with different body compositions and different maturation stages. Adiposity did not interfere with RMS in adolescents. Boys had higher MIP and MEP values compared to girls. Therefore, the reference values proposed by the equations do not consistently match RMS in the adolescents studied. This context reinforces the need for new studies that are related to RMS to establish normality values and propose equations that represent the youth population.

Respiratory Muscle Strength in Patients with Coronary Heart Disease and Different Musculoskeletal Disorders

Aim. To measure respiratory muscle strength (RMS) in patients with coronary heart disease (CHD) and different musculoskeletal disorders (MSD).Material and methods. Patients were divided in four groups according to the MSD. Group I included 52 (13.4%) patients with sarcopenia, group II included 28 (7.2%) patients with osteopenia, group III included 25 (6.5%) patients with osteosarcopenia, group IV included 282 (72.9%) patients without MSD. All patients underwent the assessment of maximal expiratory (МЕР) and maximal inspiratory mouth pressures (MIP).Results. The mean RMS values were lower than the normative values, and the strength of the expiratory muscles was 1.25 times lower compared to the inspiratory muscles. Both of these parameters were within the normal range in 191 (49.3%) patients, and lower values were noted in 196 (50.7%). An isolated decrease in MIP was observed in 24.8% of patients, an isolated decrease in МЕР in 6.5%, a combined decrease in MIP and МЕР in 19.4% of patients. Comparative analysis of МЕР and MIP (depending on the MSD) did not demonstrate statistically significant differences. Lower МЕР (76.9%) and MIP (75%) values were noted mainly in the group of patients with sarcopenia. A similar pattern was notes in patients with osteosarcopenia and in patients without MSD. Normative values of RMS were observed in patients with osteopenia. Correlation analysis revealed a unidirectional relationship between RMS and the parameters of muscle function (hand grip strength, muscle area and musculoskeletal index) and a multidirectional relationship between МЕР and BMI (r -0.743, p=0.013), MIP and patient age (r -0.624, p=0.021).Conclusion. Respiratory muscle weakness was diagnosed in half of the patients with coronary heart disease. There were no statistically significant differences in RMS between patients with MSD and isolated CHD, despite lower values in the group with MSD. Correlation analysis revealed an association between RMS and muscle function.

Natural history of respiratory muscle strength in spinal muscular atrophy: a prospective national cohort study

BackgroundRespiratory complications are the most important cause of morbidity and mortality in spinal muscular atrophy (SMA). Respiratory muscle weakness results in impaired cough, recurrent respiratory tract infections and eventually can cause respiratory failure. We assessed longitudinal patterns of respiratory muscle strength in a national cohort of treatment-naïve children and adults with SMA, hypothesizing a continued decline throughout life.MethodsWe measured maximal expiratory and inspiratory pressure (PEmax and PImax), Sniff Nasal inspiratory pressure (SNIP), peak expiratory flow (PEF), and peak cough flow (PCF) in treatment-naïve patients with SMA. We used mixed-models to analyze natural history patterns.ResultsWe included 2172 measurements of respiratory muscle function from 80 treatment-naïve patients with SMA types 1c-3b. All outcomes were lower in the more severe phenotypes. Significant differences in PEF were present between SMA types from early ages onwards. PEF decline was linear (1–2%/year). PEF reached values below 80% during early childhood in types 1c-2, and during adolescence in type 3a. PEmax and PImax were severely lowered in most patients throughout life, with PEmax values abnormally low (i.e. < 80 cmH2O) in virtually all patients. The PEmax/PImax ratio was < 1 throughout life in all SMA types, indicating that expiratory muscles were most affected. All but SMA type 3b patients had a lowered PCF. Patients with types 2b and 3a had PCF levels between 160 and 270 L/min, those with type 2a around 160 L/min and patients with type 1c well below 160 L/min. Finally, SNIP was low in nearly all patients, most pronounced in more severely affected patients.ConclusionsThere are clear differences in respiratory muscle strength and its progressive decline between SMA types. We observed lower outcomes in more severe SMA types. Particularly PEF may be a suitable outcome measure for the follow-up of respiratory strength in patients with SMA. PEF declines in a rather linear pattern in all SMA types, with clear differences at baseline. These natural history data may serve as a reference for longer-term treatment efficacy assessments.

Respiratory Muscle Strength: New Technology for Easy Assessment.

Respiratory muscle strength (RMS) is associated with good functionality of the respiratory system. For the general population, it refers to the quality of life, and for the athletes, is related to greater performance. In this study, a comparison was made between two different portable devices, MicroRPM (CareFusion, Kent, United Kingdom) and AirOFit PRO™ (AirOFit, Copenhagen, Denmark), assessing the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP). Twenty-one male professional athletes were evaluated on a voluntary basis and randomly used the devices for RMS assessment, while all athletes underwent Pittsburgh Sleep Quality Index (PSQI), pulmonary function tests and ergospirometry. All measurements of MIP and MEP were made with the same methodology and all participants after the efforts answered the question "easy-operation device-information" and dyspnea and/or respiratory fatigue during trials with the CR10 scale. Results showed statistical differences between VO2max and maximal respiratory strength both for AirOFit PRO™ (r=0.526, p=0.014) and in MicroPRM (r=0.567, p=0.007). The PSQI score showed statistical differences in % of predicted values in MEP with the AirOFit PRO™ device (r=0.478, p=0.028). Athletes reported that the AirOFit PRO™ device is easier in operation as a device and provides more information during trial comparisons to MicroPRM (p=0.001). Athletes reported that the AirOFit PRO™ device is easier in operation as a device and provides more information during the trial compared to MicroPRM. The results did not show differences in RMS (MIP and MEP) between devices (p>0.05). For the people who want to train with tele-exercise and/or tele-rehabilitation, the AirOFit PRO™ device would be an important and safe training solution.

Lung Function and Respiratory Muscle Adaptations of Endurance- and Strength-Trained Males.

Diverse exercise-induced adaptations following aerobic endurance compared to strength-training programs is well documented, however, there is paucity of research specifically focused on adaptations in the respiratory system. The aim of the study was to examine whether differences in lung function and respiratory muscle strength exist between trainers predominately engaged in endurance compared to strength-related exercise. A secondary aim was to investigate if lung function and respiratory muscle strength were associated with one-repetition maximum (1RM) in the strength trainers, and with VO2 max and fat-free mass in each respective group. Forty-six males participated in this study, consisting of 24 strength-trained (26.2 ± 6.4 years) and 22 endurance-trained (29.9 ± 7.6 years) participants. Testing involved measures of lung function, respiratory muscle strength, VO2 max, 1RM, and body composition. The endurance-trained compared to strength-trained participants had greater maximal voluntary ventilation (MVV) (11.3%, p = 0.02). The strength-trained compared to endurance-trained participants generated greater maximal inspiratory pressure (MIP) (14.3%, p = 0.02) and maximal expiratory pressure (MEP) (12.4%, p = 0.02). Moderate–strong relationships were found between strength-trained respiratory muscle strength (MIP and MEP) and squat and deadlift 1RM (r = 0.48–0.55, p ≤ 0.017). For the strength-trained participants, a strong relationship was found between MVV and VO2 max (mL·kg−1·min−1) (r = 0.63, p = 0.003) and a moderate relationship between MIP and fat-free mass (r = 0.42, p = 0.04). It appears that endurance compared to strength trainers have greater muscle endurance, while the latter group exhibits greater respiratory muscle strength. Differences in respiratory muscle strength in resistance trainers may be influenced by lower body strength.

Effect of respiratory muscle strengthening on rowing performance

Background: Respiratory muscle training (RMT) has been proposed as a beneficial means of improving respiratory muscle strength (RMS) and respiratory muscle fatigue (RMF) in athletes.&#x0D; Aims and Objective: The aim of this study was to determine the effects of a 12-week specific RMT program on the RMS, RMF and rowing ergometer performance in highly- trained rowers.&#x0D; Materials and Methods: Twenty professional rowers aged 20-35 years were recruited for the study during the competitive period and randomly grouped into an experimental (n=11) or control (n=9) group. Baseline measurements of maximal inspiratory and expiratory mouth pressures were obtained with a portable handheld mouth pressure meter while performance was assessed by 2000m and 5000m rowing ergometer machine. Subsequently rowers in the experimental group were prescribed a novel RMT program comprising of specific breathing and abdominal muscle exercises while the control group was prescribed a “general exercise program” for non- respiratory muscles for a 12-week period. RMF was assessed by calculating the difference between the pre-exercise and post-exercise mouth pressures.&#x0D; Results: Respiratory muscle strength improved overtime in the experimental and the control group following the respective training programs (p&lt;0.05) with the experimental group showing higher RMS and lower RMF. However, there were no statistically significant differences in RMS and RMF between the two groups (P&gt;0.05). More importantly, rowing ergometer performance improved significantly in the experimental group compared to the control (p&lt;0.01).&#x0D; Conclusion: The results suggest that the novel RMT program had a significant effect in improving rowing performance, although the effect on RMS and RMF was not significant.

Unsupervised low-intensity home exercises as an effective intervention for improving physical activity and physical capacity in the community-dwelling elderly.

[Purpose] The purpose of this study was to examine the effectiveness of unsupervised low-intensity home exercises in improving physical activity and physical capacity for daily activities among the community-dwelling elderly. [Participants and Methods] We included 24 female older participants and divided them into two groups: 14 in the resistance training group and 10 in the fast walking group. The resistance training group performed shoulder joint flexion and abduction exercises using a resistance tube twice daily (in the morning and afternoon). Participants in the fast walking group walked fast for 3,000 steps once daily. Both groups continued the exercise intervention for 6 months. We measured the forced vital capacity, respiratory muscle strength, physical activity, walking distance in the 6-min walk test, grip strength, and knee extension strength before and after the intervention. [Results] The forced vital capacity significantly increased in the resistance training group, whereas the moderate-intensity physical activity time significantly increased in both groups and the vigorous-intensity physical activity time increased in the fast walking group only. We observed no intergroup differences in respiratory muscle strength, 6-min walking distance, grip strength, or knee extension strength. [Conclusion] The results of this study suggest that low-intensity home exercises can improve pulmonary function and physical activity and should be recommended for promoting health in the community-dwelling elderly.

Differences in Respiratory Muscle Strength in Well-nourished versus Malnourished Hospitalized Patients

Differences in Respiratory Muscle Strength in Well-nourished versus Malnourished Hospitalized Patients

Monitoring respiratory muscle strength assists in early diagnosis of respiratory dysfunction as opposed to the isolated use of pulmonary function evaluation in amyotrophic lateral sclerosis

It was study the relationship between respiratory muscle strength and forced vital capacity (FVC) in patients with amyotrophic lateral sclerosis (ALS) versus healthy subjects. Pulmonary function and respiratory muscle strength [maximal inspiratory (PImax), maximal expiratory (PEmax) and sniff nasal inspiratory pressure (SNIP)] were assessed in patients with ALS and healthy subjects, matched using cutoffs established in the literature for impaired pulmonary function and respiratory muscle weakness. Twenty-eight ALS patients and 28 healthy subjects were studied. We found sensitivity and specificity for PImax, PEmax and SNIP of 75/58%, 81/67% and 75/67%. The Receiver Operating Characteristic curve (ROC curve) indicated that the variables PImax, PEmax and SNIP can identify differences in respiratory muscle strength between ALS and healthy individuals at 0.89, 0.9 and 0.82, respectively. A positive correlation was recorded between FVC (%) versus SNIP, PImax and PEmax. In ALS, monitoring respiratory muscle strength assists in early diagnosis of respiratory dysfunction as opposed to the isolated use of FVC.

Effect of posture on oxygenation and respiratory muscle strength in convalescent infants

Objective: To determine if differences in respiratory muscle strength could explain any posture related effects on oxygenation in convalescent neonates. Methods: Infants were examined in three postures: supine, supine with...

Lung function in patients with diabetes mellitus

Lung function was assessed in 35 nonsmoking adults with insulin dependent diabetes mellitus and 34 matched control subjects. The tests included spirometry, lung volumes, CO transfer factor and maximum respiratory pressures. Additionally, in subjects under 35 years of age (20 patients and 18 controls) measurements of CO transfer factor were obtained during exercise at three different workloads. Random blood glucose and glycosylated haemoglobin were measured and each patient's diabetic history was recorded. The total lung capacity (TLC) in the patients was lower than those recorded for the controls (P less than 0.05) but there were no significant differences in respiratory muscle strength between the groups. In the young group of patients (less than 35 years) the transfer factor for CO (TLCO) was similar but the volume corrected transfer coefficient (KCO) was higher at rest than in the controls (P less than 0.02). The KCO remained high in these patients during exercise. The older patients (greater than 35 years) showed a lower TLCO (P less than 0.01) with a similar KCO to the controls. The association of a reduction in TLC and higher KCO in the young patients suggests an extrapulmonary mechanism of lung volume restriction. This is not attributable to muscle weakness but might be due to limited expansion of the rib cage. In older patients any tendency for KCO to rise may be masked by disease-related changes in the pulmonary microvasculature.

Relationship between respiratory muscle function and age, sex, and other factors.

To investigate the effects of gender and age on respiratory muscle function, 160 healthy volunteers (80 males, 80 females) were divided into four age groups. Twenty-eight of the male subjects were smokers. After the subjects were familiarized with the experimental procedure, respiratory muscle strength, inspiratory muscle endurance, and spirometric function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, tidal volume, breathing rate, and duty cycle, were measured. The respiratory muscle strength was indicated by the maximal static inspiratory and expiratory pressures (PImmax and PEmmax). Inspiratory muscle endurance was determined by the time the subject was able to sustain breathing against an inspiratory pressure load on a modified Nickerson-Keens device. The results showed that 1) except for inspiratory muscle endurance and FEV1/FVC, men had greater respiratory muscle and pulmonary functions than women, 2) respiratory muscle function and pulmonary function decreased with age, 3) smoking tended to lower duty cycle and FEV1/FVC and to enhance PE,mmax, and 4) inspiratory muscle endurance was greater in men who were physically active than in those who were sedentary. Therefore we conclude that there are sexual and age differences in respiratory muscle strength and pulmonary function and that smoking or physical activity may affect respiratory muscle function.