UNASSIGNED: Respiratory complications are a leading cause of mortality post spinal cord injury (SCI). Along with breathing, respiratory muscles have a role in maintaining seated balance. Postinjury breathing influences respiratory muscle function. Preliminary evidence indicates a relation between respiratory muscle function and seated balance in people with chronic SCI dwelling in the community, but the relationship between balance and body habitus has not been explored.
UNASSIGNED: To explore the relationships among inspiratory muscle function, functional seated balance (FSB), and body habitus in people with SCI.
UNASSIGNED: A convenience sample of inpatients with SCI (C5-T12) aged 18 to 60 years who were using a wheelchair was recruited from November 2022 to March 2023. Those with additional neurological disorders or respiratory support were excluded. Respiratory muscle function measures included maximal inspiratory pressure (MIP), sustained MIP (SMIP), and Fatigue Index Test (FIT). FSB was scored using the Function in Sitting Test (FIST). Body habitus was assessed using the axillary: umbilical (A:U) ratio. Spearman correlations explored the relationships.
UNASSIGNED: Thirty-eight of 42 screened participants were eligible and participated (male, 32). Levels of injury ranged from C5 to T12. The mean (SD) age and duration of injury of the sample was 25.61 (6.68) years and 31.03 (28.69) months, respectively. SMIP and FIT correlated significantly with FSB (r s= .441, p = .01, and r s= .434, p = .006, respectively). A significant correlation between SMIP and A:U ratio (r s= -.330, p = .043) was observed.
UNASSIGNED: We observed a significant correlation between inspiratory pressure parameters and both functional seated balance and body habitus, adding to evidence on postural role of respiratory muscles.

BACKGROUND: Inspiratory muscle fatigue has been shown to have effects on limbs blood flow and physical performance. This study aimed to evaluate the influence of an inspiratory muscle fatigue protocol on respiratory muscle strength, vertical jump performance and muscle oxygen saturation in healthy youths.
METHODS: A randomized and double-blinded controlled clinical trial, was conducted. Twenty-four participants aged 18-45 years, non-smokers and engaged in sports activity at least three times a week for a minimum of one year were enrolled in this investigation. Participants were randomly assigned to three groups: Inspiratory Muscle Fatigue (IMFG), Activation, and Control. Measurements of vertical jump, diaphragmatic ultrasound, muscle oxygen saturation, and maximum inspiratory pressure were taken at two stages: before the intervention (T1) and immediately after treatment (T2).
RESULTS: The IMFG showed lower scores in muscle oxygen saturation and cardiorespiratory variables after undergoing the diaphragmatic fatigue intervention compared to the activation and control groups (p < 0.05). For the vertical jump variables, intragroup differences were found (p < 0.01), but no differences were shown between the three groups (p > 0.05).
CONCLUSIONS: Inspiratory muscle fatigue appears to negatively impact vertical jump performance, muscle oxygen saturation and inspiratory muscle strength in healthy youths.
BACKGROUND: ClinicalTrials.gov ID: NCT06271876. Date of registration 02/21/2024. https://clinicaltrials.gov/study/NCT06271876 .

BACKGROUND: Although pressure support ventilation is one of the most commonly used assisted ventilation modes in intensive care units, there is still a lack of precise strategies for setting pressure support. By performing an end-inspiratory airway occlusion, the difference between the peak and plateau airway pressure, which is defined as pressure muscle index (PMI), can be easily measured on the ventilator screen. Previous studies have shown that PMI is accurate in detecting high and low inspiratory effort. No study has been conducted to investigate the use of PMI as an indicator for setting inspiratory pressure support.
METHODS: This is a study protocol for a prospective, single-centre, randomised controlled, pilot trial. Sixty participants undergoing pressure support ventilation will be randomly assigned in a 1:1 ratio to the control group or intervention group, with pressure support adjusted according to standard care or guided by the PMI strategy for 48 hours, respectively. The feasibility of the PMI-guided strategy will be evaluated. The primary endpoint is the proportion of inspiratory effort measurements within a well-accepted \'normal\' range, which is predefined as oesophageal pressure-time product per minute between 50 and 200 cmH2O⋅s/min, for each patient during 48 hours of pressure support adjustment.
BACKGROUND: The study protocol has been approved by Beijing Tiantan Hospital (KY2023-005-02). The data generated in the present study will be available from the corresponding author on reasonable request. The results of the trial will be submitted to international peer-reviewed journals.
BACKGROUND: NCT05963737; ClinicalTrials.org.

To investigate the clinical effects and application value of self-made disseminating and descending breathing exercises on home rehabilitation of patients with stable chronic obstructive pulmonary disease (COPD). Seeking to generate concepts for creating novel, convenient, and efficient COPD prognosis rehabilitation exercises aimed at enhancing the well-being and rehabilitation confidence of both COPD patients and their families. A total of 70 COPD patients admitted to our outpatient department from July 2019 to September 2021 were randomly divided into the exercise group (n = 35) and the control group (n = 35). The control group received routine breathing training, while the exercise group was treated with self-made disseminating and descending breathing exercises. The respiratory function, including pulmonary function (FVC, FEV1, FEV1/FVC) and respiratory muscle strength (MIP, MEP), exercise tolerance (6-min walking distance, 6MWT), Modified Medical Research Council Dyspnea Scale (mMRC, Borg), COPD quality of life score (CAT, SGRQ), anxiety and depression scores (HAMA, HAMD) were compared between the two groups after 12-week exercise. After 12-week training, the FEV1, MIP, and MEP in the exercise group were significantly higher than those in the control group (p < 0.001), and the 6MWT was significantly increased in the exercise group compared to the control group (p < 0.001); while the mMRC, Borg score, the scores of CAT, SGRQ, HAMA, and HAMD were found significantly lower than those in the control group (p < 0.001). The self-made disseminating and descending breathing exercises can improve respiratory function and reduce symptoms of dyspnea in COPD patients, while enhancing exercise tolerance and relieving anxiety and depression, and are worthy of clinical application.

Patients receiving mechanical ventilation in the intensive care unit (ICU) frequently develop contractile weakness of the diaphragm. Consequently, they may experience difficulty weaning from mechanical ventilation, which increases mortality and poses a high economic burden. Because of a lack of knowledge regarding the molecular changes in the diaphragm, no treatment is currently available to improve diaphragm contractility. We compared diaphragm biopsies from ventilated ICU patients (N = 54) to those of non-ICU patients undergoing thoracic surgery (N = 27). By integrating data from myofiber force measurements, x-ray diffraction experiments, and biochemical assays with clinical data, we found that in myofibers isolated from the diaphragm of ventilated ICU patients, myosin is trapped in an energy-sparing, super-relaxed state, which impairs the binding of myosin to actin during diaphragm contraction. Studies on quadriceps biopsies of ICU patients and on the diaphragm of previously healthy mechanically ventilated rats suggested that the super-relaxed myosins are specific to the diaphragm and not a result of critical illness. Exposing slow- and fast-twitch myofibers isolated from the diaphragm biopsies to small-molecule compounds activating troponin restored contractile force in vitro. These findings support the continued development of drugs that target sarcomere proteins to increase the calcium sensitivity of myofibers for the treatment of ICU-acquired diaphragm weakness.

UNASSIGNED: The aim of this study was to measure the diaphragm volume using three-dimensional computed tomography (3D-CT) and verify its validity.
UNASSIGNED: This was a retrospective study of existing samples.
UNASSIGNED: Participants comprised five male patients, aged 65-70 years, who underwent preoperative chest CT (with a slice thickness of 0.5 mm) before coronary artery bypass surgery. The diaphragm was selectively extracted using a workstation to reconstruct a stereoscopic image, and the total muscle volume was measured. To confirm the accuracy and reproducibility of diaphragm muscle volume measurements on CT, all cases were measured three times by two observers, and intraclass correlation coefficients (ICCs) and interobserver correlations were determined.
UNASSIGNED: Observers #1 and #2 reported an average diaphragm volume of 256.7±33 cm3 and 259.3±36 cm3, respectively. The ICC analyses yielded Cronbach\'s alphas of 0.992 and 0.981 from both observers, and the interobserver correlation was 0.991. The ICC of a single measurement and the average measurement was 0.984 (95% confidence interval: 0.998-0.884) and 0.992 (95% confidence interval: 0.999-0.939), respectively.
UNASSIGNED: To our knowledge, this study is the first to standardize the method for measuring the total diaphragm volume and examine the reproducibility and validity of the new method. The diaphragm could be selectively extracted and reconstructed. Measurement of the total diaphragm muscle volume using a workstation to reconstruct a stereoscopic image is feasible and highly reproducible. This technique can be reliably employed to evaluate diaphragm volume, thickness, and morphology.

Respiratory diseases significantly affect respiratory function, making them a considerable contributor to global mortality. The respiratory muscles play an important role in disease prognosis; as such, quantitative analysis of the respiratory muscles is crucial to assess the status of the respiratory system and the quality of life in patients. In this study, we aimed to develop an automated approach for the segmentation and classification of three types of respiratory muscles from computed tomography (CT) images using artificial intelligence. With a dataset of approximately 600,000 thoracic CT images from 3,200 individuals, we trained the model using the Attention U-Net architecture, optimized for detailed and focused segmentation. Subsequently, we calculated the volumes and densities from the muscle masks segmented by our model and performed correlation analysis with pulmonary function test (PFT) parameters. The segmentation models for muscle tissue and respiratory muscles obtained dice scores of 0.9823 and 0.9688, respectively. The classification model, achieving a generalized dice score of 0.9900, also demonstrated high accuracy in classifying thoracic region muscle types, as evidenced by its F1 scores: 0.9793 for the pectoralis muscle, 0.9975 for the erector spinae muscle, and 0.9839 for the intercostal muscle. In the correlation analysis, the volume of the respiratory muscles showed a strong correlation with PFT parameters, suggesting that respiratory muscle volume may serve as a potential novel biomarker for respiratory function. Although muscle density showed a weaker correlation with the PFT parameters, it has a potential significance in medical research.

OBJECTIVE: Posture correction bands (PCBs) have been proposed as aids to help chest expansion and to enhance respiratory function. However, the impact of PCBs on community-based older individuals engaged in inspiratory muscle training (IMT) at home remains unclear.
METHODS: Community-based individuals aged 65 years and older were divided into the PCB group, wearing PCBs, and the NPCB group, not wearing PCBs. The IMT regimen lasted 8 weeks, with sessions 5 times a week, including 4 sets per day and 15 repetitions per set. Training intensity was set at 50% of the maximum inspiratory pressure of each subject. To assess the effects of IMT, respiratory function, 6-minute walk test, and grip strength were measured before, during, and after the training period. Data were analyzed using repeated-measures analysis of variance, with post-hoc evaluation employing Bonferroni correction.
RESULTS: A total of 40 subjects were evenly divided into the PCB group and the NPCB group, with 20 subjects in each group. No significant difference was observed in respiratory muscle strength based on PCB use. However, during the initial 4 weeks, the PCB group exhibited a trend towards an increase in respiratory muscle strength compared to the NPCB group; this trend, however, did not prove to be statistically significant by the end of the 8-week period. Performance on the 6-minute walk test significantly improved in both groups.
CONCLUSIONS: The PCB group exhibited a tendency for increase in respiratory muscle strength in the first 4 weeks; however, ultimately there was no significant difference compared to the NPCB group.
BACKGROUND: This study was registered with the Clinical Research Information Service, part of the World Health Organization\'s International Clinical Trials Registry Platform (Clinical Research Information Service No. KCT0008075).

Systematic reviews support the benefits of inspiratory muscle training (IMT) for exercise performance. Recently, many health benefits from IMT have been reported in older adults. Therefore, this work reviewed the literature focusing on IMT effects beyond physical performance in older adults, such as cardiorespiratory, metabolic, and postural balance outcomes. Searches were conducted with the following terms: (\"respiratory muscle training\" OR \"inspiratory muscle training\") OR (\"inspiratory muscle strength training\") AND (\"elderly\" OR \"older\" OR \"aging\" OR \"aging\"), and using the databases: MEDLINE (PubMed), SCOPUS and EUROPE PMC. Of the 356 articles found, 13 matched the inclusion criteria after screening. Based on reviewed studies, four to eight weeks of IMT (Mostly from 50 % up to 75 % of MIP, 7 days/week) improve cardiac autonomic control at rest and post-exercise, cerebrovascular response to orthostatic stress, static and dynamic balance, blood pressure control, endothelial function, and oxidative stress in older adults. The benefits of IMT in cardiac autonomic and vascular functions are reversed after training cessation. It thus appears that IMT promotes broad physiological gains for the older population. It is necessary to carry out more randomized clinical trials on the subject to confirm the findings of this research.

Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a rare form of idiopathic interstitial pneumonia. We report a case of a patient with iPPFE in whom postural changes improved diaphragmatic excursion (DE) and exercise tolerance. Chest radiography showed a greater elevation of the diaphragm at maximum expiration in the supine position than the standing position. DE measured by ultrasonography was higher in the supine position than the standing position. The findings may suggest greater diaphragm movement in the supine position, leading to successful rehabilitation and improved exercise endurance. There is no effective treatment for iPPFE; therefore, an innovative treatment strategy is warranted.