Comparison Between the Effectiveness of Mackenzie Exercise and William Flexion Exercises for Treatment of Non-Specific Low Back Pain in Obese People

Background: Low back pain (LBP) is one of the most common musculoskeletal disorders worldwide, with a lifetime prevalence of 84% and chronic nonspecific forms affecting approximately 23% of individuals. Chronic LBP, defined as pain persisting beyond 12 weeks, is influenced by multiple risk factors including sex, middle age, sedentary lifestyle, strenuous activity, occupational overload, smoking, and obesity. Conservative management frequently emphasizes therapeutic exercise, with approaches such as aerobic training, flexibility exercises, McKenzie extension, and William’s flexion routines demonstrating varying degrees of efficacy depending on the protocol applied. Objective: To compare the effectiveness of McKenzie extension and William’s flexion exercises in the management of nonspecific low back pain among obese individuals. Methods: A pre-test/post-test clinical trial was conducted on 32 participants who met inclusion criteria and provided informed consent. Ethical approval was secured prior to commencement. Participants were purposively allocated into two groups of 16 each. Group A underwent William’s flexion exercise program, which included double knee-to-chest, single knee-to-chest, and straight leg raise exercises, performed 5–8 repetitions per session, five times weekly for four weeks. Group B followed a McKenzie extension protocol comprising prone extensions and pelvic bridging with identical frequency and duration. Pain was measured using the Visual Analogue Scale (VAS), and disability was evaluated with the Oswestry Low Back Pain Disability Index (OLBPDI). Data were analyzed using paired and independent t-tests, with p < 0.05 considered statistically significant. Results: Group A demonstrated a reduction in mean VAS score from 7.19 ± 1.11 to 2.00 ± 1.32 and improvement in OLBPDI score by 1.00 ± 0.89 (p < 0.001). Group B showed a similar decrease in VAS from 7.69 ± 0.95 to 2.50 ± 1.32 and improvement in OLBPDI by 1.31 ± 0.60 (p < 0.001). Independent samples analysis revealed no statistically significant difference between groups for post-intervention pain (p = 0.291) or disability (p = 0.362). Conclusion: Both McKenzie and William’s flexion exercises significantly reduced pain intensity and disability in obese patients with nonspecific low back pain. The absence of significant between-group differences indicates that either protocol may be effectively applied in clinical practice to improve patient outcomes.