RESUMEN
OBJECTIVE: To investigate and compare the effectiveness of aquatic physiotherapy and therapeutic exercise in the physical and functional performance of patients with chronic low back pain. METHODS: Twenty-six participants were randomized into 3 groups, namely an aquatic physiotherapy group (AG), a therapeutic exercise group (EG), and a control group (CG). The pain, disability, and quality of life were compared before and after the exercise protocols for 2 months, twice a week, on alternate days, for 60 min. For statistical analyses, the Kruskal-Wallis test was used to test the difference between the groups; the Wilcoxon test and the effect size were used for before-and-after comparisons. RESULTS: Twenty participants completed the study. There was a significant difference improvement in pain between the AG and the EG (p = 0.004), between the EG and the CG (p = 0.05), and in social role functioning between the groups (p = 0.02). No differences were observed in the other analyzed variables between the groups. Compared to the pre-treatment state, there were significant improvements in the AG in terms of pain (p = 0.02), functionality (p = 0.03), and general health status (p = 0.04). CONCLUSION: The AG group showed significant and clinical improvement in pain, disability, and quality of life. Improvements related to social aspects were found in the EG compared to the CG. The water provides a safe environment that facilitates the onset of exercise, so aquatic physiotherapy could be considered the first recommendation for patients with low back pain.