Correlation between abdominal muscle strength and pulmonary function in subjects with low back pain

Introduction: The diaphragm is man's main respiratory muscle. The role of the abdominal muscles is seen in both quiet and forceful breathing. Abdominal muscle function could be affected in subjects with back pain. Few studies are done about the relation between expiratory muscle strength and pulmonary function. So the aim of this study was to evaluate the correlation of abdominal muscle strength with pulmonary function in patients with low back pain. Materials and methods: Sixty subjects with low back pain were included in the study. Subjects with history of acute or chronic respiratory disorders were excluded. Abdominal muscle strength was measured by curl up test and FEV1/FVC and peak expiratory flow rate (PEFR) was measured to assess pulmonary functional. Results: Using Spearman test for correlation between abdominal muscle strength and FEV1/FVC (r= -0.27, p=0.03), and between abdominal muscle strength and PEFR (r=0.34, p=0.007) was seen. Conclusion: There was a weak correlation between abdominal muscle strength and pulmonary function in subjects of low back pain.