Abstract
OBJECTIVES: The neural respiratory drive (NRD) is a critical determinant of breathlessness, influenced by the balance between ventilatory load and respiratory muscle capacity. This study aimed to evaluate the impact of body positions on NRD in young healthy adults (18-50 years) and to identify the optimal position for assessing NRD among the healthy subjects. METHODS: Surface electromyography (sEMG) data from the 2nd intercostal space parasternal muscle was collected in supine, sitting, and standing positions among young healthy adults. NRD parameters, including EMG Para max% and Neural Respiratory Drive Index (NRDI), were analysed and compared among positions using ANOVA. RESULTS: Significant differences in NRD values were observed across body positions, with standing vs. supine vs. sitting yielding higher values in both sexes respectively (Males: 5.113±0.437, 4.404±0.576, 4.913±0.623; P<0.001 and Females: 7.444±0.416, 6.435±0.266, 6.748±0.390; P<0.001). Post hoc analysis reveals significant difference in standing vs supine vs sitting position. These findings highlight the influence of body position on NRD measurements. CONCLUSIONS: The study emphasizes the importance of considering body position when evaluating NRD in healthy individuals. These factors should also be taken into account in clinical assessments to ensure accurate interpretation of NRD and related respiratory functions.