Effectiveness of back therapeutic exercises and Pilates on the clinical improvement of the intensity of chronic low back pain and determination of the minimal clinically important improvement threshold from treatments in a hospital setting

Abstract

The primary aim was to compare the effectiveness of therapeutic back exercises and Pilates in reducing chronic low back pain and to determine the threshold of improvement and the difference in pre- and post-treatment scores considered clinically relevant for patients. Methodology: A total of 53 patients with chronic low back pain were randomly assigned to two groups: one with 27 participants performing Pilates and another with 26 participants following a back exercise program. The treatment consisted of sessions twice a week for three months. Pain intensity was assessed before and after treatment using the Visual Analog Pain Scale. A clinically relevant threshold was defined as a sufficient reduction in pain score for patients to feel "very satisfied." A Receiver Operating Characteristic Curve analysis was used to determine the sensitivity and specificity of the improvement threshold. Additionally, a linear regression model was applied to analyze the relationship between score difference and the percentage of improvement. Results: Although both groups showed significant improvements in pain reduction after treatment, there were no statistically significant differences between them. The average reductions in both groups did not exceed two points (Back Exercise Group = 1.43 points, Pilates Group = 1.82 points), thus not reaching the two-point average improvement required to meet the clinically relevant improvement threshold. However, at an individual level, 45.83% of the Pilates group and 37.5% of the back exercise group achieved a clinically relevant improvement (≥30% improvement). The improvement threshold of 31.4%, equivalent to a two-point reduction, was correlated with greater clinical satisfaction (sensitivity 84%, specificity 87%). Conclusions: Both treatments produced beneficial effects in reducing chronic low back pain. However, the average improvement was not clinically relevant for the overall sample. At an individual level, a significant proportion of patients achieved clinically relevant improvement, particularly in the Pilates group. The 31.4% improvement threshold serves as an additional indicator for evaluating the clinical relevance of treatments. Keywords: Therapeutic back exercises, Pilates, chronic low back pain, Visual Analog Scale for Pain, Minimal Clinically Important Change.

Keywords

• Ejercicios terapéuticos para la espalda, Pilates, dolor lumbar crónico, Escala Visual Analógica del Dolor, Cambio Mínimo Clínicamente Importante.