Effects of progessive vs. constant protocol whole-body vibration on muscle activation, pain, disability and functional performance in non-specific chronic low back pain patients: a randomized clinical trial.

Background and objective: Non-specific chronic low back pain (NSCLBP) is a prevalent condition causing significant disability and functional impairment. Whole-body vibration exercise (WBVE) has emerged as a new treatment method, but additional research is necessary to determine the optimal parameters of WBVE that would be beneficial for patients experiencing chronic low back pain (CLBP). This study aims to investigate the effects of two type of WBVE (constant vs progressive) on pain, disability, functional performance, and muscle activity in patients with NSCLBP.

Methods: Thirty-two individuals diagnosed with chronic low back pain (CLBP) without any specific causes were enrolled and randomly assigned to one of two intervention groups: a constant/fixed protocol WBVE group or a progressive protocol WBVE group. Participants underwent WBVE sessions for around 30 min, thrice weekly over a period of 8 weeks. Primary outcomes assessed included pain intensity, functional disability, functional performance, and electromyographic activity of core musculature, measured at baseline and upon completion of the intervention period. Temporal changes of each outcome variable across different periods and between groups were measured with repeated measures 2×2 mixed ANOVA. Further, the paired t-test was performed to compare pre- and post-treatment values within each group.

Results: Significant improvements were observed in both the constant and progressive WBVE protocol groups. Pain intensity decreased by 64.2% (p < 0.001) in the constant group and by 61.1% (p < 0.001) in the progressive group. Functional disability decreased by 48.1% (p < 0.001) in the constant group and by 53.3% (p < 0.001) in the progressive group. Functional performance improved by 16.5% (p < 0.001) in the constant group and by 16.9% (p < 0.001) in the progressive group. Electromyography (EMG) demonstrated significant improvements across all measured variables except % maximum voluntary isometric contraction (%MVIC) of external obliques (EO) in both intervention groups with time (p < 0.001). There was no statistically significant difference in the magnitude of improvement between the constant and progressive WBVE protocols (p > 0.05), indicating both modalities' effectiveness in ameliorating CLBP symptoms and associated functional impairments.

Conclusion: The study demonstrates that both progressive and constant WBVE protocols are equally effective in reducing pain and disability in NSCLBP patients. These findings support the inclusion of progressive WBVE in clinical practice, offering a flexible treatment option that can be tailored to individual patient needs, ensuring both tolerability and effectiveness. This contributes valuable evidence towards optimizing WBVE protocols for managing NSCLBP.