Effects of Adding MedX Lumbar Extension or Deadlift Exercises to a Core Stabilization Program on Extensor Strength, Disability, and Pain in Men with Chronic Low Back Pain: A Randomized Pilot Trial

Background and Objectives: Despite extensive research on the management of chronic low back pain, evidence regarding the additional benefits of incorporating lumbar extension-specific exercises into conventional core stabilization programs remains limited. Therefore, the primary objective of this pilot study was to evaluate the feasibility of three 8-week exercise interventions in men in their 30s with chronic low back pain, including recruitment feasibility, retention rate, adherence to exercise sessions, intervention acceptability, and safety. The secondary and exploratory objective was to determine preliminary intervention effects and variability parameters for lumbar extensor strength, activities of daily living, and pain intensity. These findings may help in designing, selecting the outcome, and calculating sample size of a future definitive randomized controlled trial with adequate statistical power. Methods: The study included 30 male participants aged 30–39 years with low back pain persisting for more than 12 weeks. They were randomly divided into a MedX Exercise Program Group, a Deadlift Exercise Program Group, and a Core Exercise Program Group. The intervention consisted of exercise sessions conducted twice weekly for eight weeks. The intervention was evaluated by measuring lumbar extensor strength, the ability to perform activities of daily living, and pain intensity before and after the intervention. The collected data were tested for normality using the Shapiro–Wilk test, and homogeneity was tested using one-way analysis of variance. Group differences between time periods were tested using two-way analysis of variance with repeated measures. For outcome variables showing significant between-group differences at baseline, additional analyses of covariance were conducted with the corresponding baseline values included as covariates. Effect sizes and 95% confidence intervals were calculated and reported for all outcome variables. As this pilot study was not designed to provide confirmatory efficacy testing, analyses of secondary outcomes were considered exploratory in nature, and no adjustments for multiple comparisons were applied. Results: All 30 participants who underwent eligibility screening were randomized, and all participants completed the 8-week intervention and follow-up assessments, resulting in a 100% retention rate. Intervention adherence was also 100%, with all 480 scheduled sessions completed (480/480). No intervention-related adverse events were reported, and complete data were available for all outcome variables. For lumbar extensor strength, a significant main effect of time was observed across all seven lumbar extension angles (all p < 0.001), indicating significant improvements within all three groups. A significant time × group interaction was observed only at 0° (p = 0.048); however, subsequent pairwise comparisons revealed no significant differences between any groups at follow-up. Activities of daily living significantly improved in all three groups, and no significant between-group differences were observed in the baseline-adjusted analysis of variance (p = 0.226). Pain intensity significantly decreased in all groups, with the largest reduction observed in the core stabilization exercise group (−78.05%). Post-hoc analyses demonstrated that the reduction in pain intensity was significantly greater in the core stabilization exercise group than in both the MedX lumbar extension exercise group (p = 0.022) and the deadlift exercise group (p = 0.042). Conclusions: All three 8-week exercise interventions were feasible, achieving complete participant retention and adherence, with no reported adverse events. Although lumbar extensor strength, activities of daily living, and pain intensity significantly improved across all groups, no additional benefits were noted from incorporating MedX lumbar extension exercises or deadlift exercises into a common core stabilization exercise program. Notably, the greatest reduction in pain intensity was observed in the core stabilization exercise-only group. Given the exploratory nature and pilot design of this study, these findings should be interpreted cautiously and require confirmation in future adequately powered randomized controlled trials.