 The qualitative description of the data will be made with percentages and frequency. The quantitative data described as means and standard deviation for the symmetrical distributions. The Kolmogorov-Smirnov test to determine distributions mean normality. A One-way analysis of variance ANOVA with repeated measurements and Bonferroni test will be used as post-hoc test to evaluate statistical significance. Within-group effect sizes will be calculated using the Cohen d coefficient interpretation. For all the study data, the P values lower than 0.05 will be consider significant. The investigators will use the Student T- test for independent sample for quantitative data and for comparisons between the COPD patients and control group and ANOVA to the comparisons within COPD group. The investigators will use Pearsons correlation test to measure the correlation between the diaphragmatic mobility and the lung functioning variables. 