The effects of submaximal neuromuscular blockade (SMNB) on the recruitment (or derecruitment) of the respiratory muscles during different types of respiratory maneuvers were studied in four healthy males infused slowly with pancuronium. The effects on lung mechanics were similar to those observed previously in that lung recoil pressure during inspiration did not change while the chest wall pressure-volume (PV) curve was shifted to the right (Rahn diagram). In each subject, SMNB produced a large increase in abdominal (gastric) and transdiaphragmatic pressures at any given lung volume during inspiration, reflecting greater diaphragmatic contribution to respiratory pressure swings. In addition, using concentric needle electrodes, we observed a marked fall in electrical (tonic and phasic) activity in the abdominal and in the intercostal/accessory muscles during SMNB but a slight increase in diaphragmatic activity. This pattern of changes was accentuated as ventilation increased. These findings indicate that the diaphragm is more resistant to curare than the other respiratory muscles in humans and that the transposition of the chest wall PV curve during SMNB is related to a loss of tonic activity in the intercostal musculature. The difference in sensitivity toward curare between the diaphragm and the other respiratory muscles is probably related to a difference in the safety margin at the neuromuscular synapses.
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http://dx.doi.org/10.1152/jappl.1980.49.6.1049 | DOI Listing |
Pulmonology
December 2025
Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.
Background: Nasal high flow (NHF) has been proposed to sustain high intensity exercise in people with COPD, but we have a poor understanding of its physiological effects in this clinical setting.
Research Question: What is the effect of NHF during exercise on dynamic respiratory muscle function and activation, cardiorespiratory parameters, endurance capacity, dyspnoea and leg fatigue as compared to control intervention.
Study Design And Methods: Randomized single-blind crossover trial including COPD patients.
Tob Induc Dis
January 2025
Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States.
Introduction: Cigarette smoking is an important risk factor in the development of dyspnea. Programs designed to strengthen the respiratory muscles can improve dyspnea in people with or without lung disease. As a first step in understanding the feasibility of offering a respiratory muscle training (RMT) program to people who are seeking help to try to quit smoking, we asked callers who contacted the New York State Quitline about their dyspnea and potential interest in a home-based RMT program.
View Article and Find Full Text PDFHum Mov Sci
January 2025
Sports Physical Therapy Laboratory, School of Physical Education and Sports Science, National and Kapodistrian University of Athens, Greece. Electronic address:
Introduction: Breathing and postural control is reported to be both neuromuscularly and mechanically interdependent. To date, the effects of voluntary abdominal and thoracic breathing (VAB and VTB) on the EMG activity of muscles involved in both respiratory and postural functions, as well as gait biomechanics related to these breathing patterns, have not been investigated in young, healthy adults. The aim of the study was to evaluate the EMG responses of neck and trunk muscles, as well as the kinematic, stability, and kinetic parameters of gait induced by VAB and VTB compared to involuntary breathing (INB).
View Article and Find Full Text PDFActa Bioeng Biomech
June 2024
2Daping Hospital, Army Medical Center, Chongqing, China.
: This study explores how thoracic orientation affects lung pressure and injury outcomes from shock waves, building on earlier research that suggested human posture impacts injury severity. : A layered finite element model of the chest was constructed based on the Chinese Visual Human Dataset (CVH), including the rib and intercostal muscle layers. The dynamic response of the chest under 12 different angle-oriented shock waves under incident pressures of 200 kPa and 500 kPa was calculated.
View Article and Find Full Text PDFFront Physiol
January 2025
Department of Rehabilitation Medicine, Qingdao Municipal Hospital, University of Health and Rehabilitation Sciences, Qingdao, China.
Background: Vocal therapy, such as singing training, is an increasingly popular pulmonary rehabilitation program that has improved respiratory muscle status in patients with chronic obstructive pulmonary disease (COPD). However, variations in singing treatment protocols have led to inconsistent clinical outcomes.
Objective: This study aims to explore the content of vocalization training for patients with COPD by observing differences in respiratory muscle activation across different vocalization tasks.
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