Motor unit involvement and activities in respiratory muscles during spirometric measurements of obstructive and restrictive lung diseases in 14-20 years male

Introduction: Breathing involves respiratory muscle activities by recruiting motor units. The obstructive and restrictive lung diseases were categorized based on spirometric measurement. Measurement of respiratory muscle function is important in the diagnosis of respiratory disease or dysfunction. Purpose: This study focuses on the involvement of motor units in diaphragm, external intercostals and latissimus dorsi muscles during voluntary contractions in young boys having obstructive and restrictive lung diseases. Materials and methods: Fifty eight young male (14-20 years) were participated and they were grouped into three (normal, restrictive and obstructive) according to their lung condition measured by Spirometry. One way ANOVA was done to understand the significant differences between the muscles of three groups. Involvement of motor unit was shown by plotting the Line diagrams. Mean and standard deviation along with one way ANOVA were calculated in case of three respiratory muscles (External intercostals, Diaphragm, and latissimus dorsi) for three groups. Results: No significant differences were found among three groups during performing Forced vital capacity (FVC), Slow vital capacity (SVC), Maximum voluntary ventilation (MVV), and Minute ventilation (MV). Line diagram shows that during FVC, SVC, and MVV responses of different muscles are higher in three different groups except during MV. Conclusion: This study states that motor unit involvement is different in the case of three different conditions. It can be concluded that restrictive and obstructive diseases might not be interpreted on the basis of only spirometric measurements in static and dynamic lung conditions. Motor unit activation and responses of major respiratory muscles were important determinants during spirometric measurements