Efficacy of Core-Strengthening and Intensive Dynamic Back Exercises on Pain, Core Muscle Endurance, and Functional Disability in Patients with Chronic Non-Specific Low Back Pain: A Randomized Comparative Study

Background: Chronic back pains are progressively disabling working individuals, including 60–80% of the general population, for which their diagnosis is challenging to healthcare workers worldwide, thereby becoming a burden to nations. Purpose: The study aimed to investigate the efficacy of core strengthening exercise (CSE) and intensive dynamic back exercise (IDBE) on pain, core muscle endurance, and functional disability in patients with chronic non-specific low back pain (LBP). Methods: The study was based on a three-arm parallel-group randomized control design. Forty-five participants with chronic non-specific LBP were recruited and randomly divided into the CSE, IDBE, and Control groups. The CSE and IDBE groups received CSE and IDBE, respectively. However, the Control group received no intervention. Numeric pain rating scale, Oswestry Disability Index, core flexors, extensors, and side bridge tests assessed pain intensity, functional disability, and endurance of core muscles. Outcome scores for the dependent variables were collected at baseline (pre-intervention) and six-week post-intervention. There were no follow-up measurements in this study. A one-way multivariate analysis of covariance (MANCOVA) was used to analyze the intervention effects on the outcomes within groups and between groups, respectively; keeping the significance-level alpha at 95%, i.e., p < 0.05. A univariate F-test was performed to observe the superiority of one treatment over another. Pearson’s correlation coefficient test was conducted to determine a relation between the dependent variables. In all statistical analyses, the level of significance α was kept at 0.05. Results: All forty-five out of sixty-three participants with chronic non-specific low back pain (male, 32 and female, 23; average age, 20.24 ± 1.46 years; average pain duration, 19.6 ± 5.42 weeks) completed the study and their data were analyzed. The MANCOVA test showed a significant difference between the treatment groups on the combined multiple endurance tests for the core muscles (flexors, extensors, side bridge tests to the right and left), Visual Analog Scale (VAS), and Oswestry Disability Index (ODI) scores after controlling for baseline scores of all the dependent variables: F (6, 12) = 23.381; p < 0.05; Wilks’ Λ = 0.033; partial η2 = 0.819. A post hoc pair-wise comparison followed by a univariate F-test indicated that a significant improvement was found between the CSE vs. IDBE vs. Control groups on the post-test scores of all the dependent variables except VAS and EET (CSE vs. IDBE only). A Pearson’s correlation coefficient test revealed a notable relation between the dependent variables. Conclusions: The experimental group CSE was found to be more effective than IDBE on improving functional disability, cores’ flexors, and side bridges’ endurance tests than IDBE. The magnitude of this improvement exceeded the minimal clinically important difference (MCID), suggesting a clinically relevant enhancement in functional disability, core flexors, and side bridge endurance for participants engaged in CSE. However, CSE vs. IDBE revealed non-significant differences on reducing pain and core extensors’ endurance. The absence of statistically significant differences suggests that the observed changes did not exceed the established MCID for pain intensity and core extensors’ endurance. In addition, partial eta-squared value revealed the superiority of CSE over IDBE and Control groups. This suggests that the observed differences between the two interventions are not only statistically significant, but also clinically relevant, surpassing the established MCID.