Efficacy of specific exercises in general population with non-specific low back pain: A systematic review and meta-analysis of randomized controlled trials

Objective Localized exercises are employed to activate, train, or restore the function of particular muscles and they are usually considered as part of treating individuals suffering low back pain. So, this systematic review and meta-analysis aimed to assess the efficacy of specific exercises in general population with non-specific low back pain (LBP). Methods We conducted electronic searches in MEDLINE/PubMed, Scopus, Web of Science (WoS), and Google scholar from January 1990 to June 2021. Initially, 47,740 records were identified. Following the removal of duplicates, 32,138 records were left. After reviewing titles and abstracts, 262 papers were chosen for thorough assessment. Among these, 208 studies were excluded, resulting in 54 trials meeting the inclusion criteria for this study. Additionally, 46 of these trials were randomized controlled trials and were further evaluated for the meta-analysis. We included trials investigating the effectiveness of exercise therapy, including isometric activation of deep trunk muscles, strengthening exercises, stabilization exercises, stretching exercises, and proprioceptive neuromuscular facilitation exercises (PNF) in LBP patients. The primary outcome was pain intensity, measured using tools such as the visual analogue scale (VAS) and numeric pain rating scale (NPRS). The secondary outcome was disability, assessed through instruments such as the Roland Morris Disability Questionnaire (RMDQ) and Oswestry Disability Index (ODI). The quality of the eligible studies was assessed using the Verhagen tool, and the level of evidence was evaluated using the GRADE approach. Results Based on the Verhagen tool, 46 trials (85.2%) were categorized as having low methodological quality, while 8 studies (14.8%) were considered to have medium methodological quality. The meta-analysis indicated a small efficacy in favor of isometric activation of deep trunk muscles (−0.37, 95% CI: −0.88 to 0.13), a moderate efficacy in favor of stabilization exercises (−0.53, 95% CI: −1.13 to 0.08), and a large efficacy in favor of PNF exercises (−0.91, 95% CI: −1.62 to −0.2) for reducing pain intensity as assessed by VAS or NPRS tools. Moreover, the meta-analysis revealed a moderate efficacy for isometric activation of deep trunk muscles (−0.61, CI: −1.02 to −0.19), and a large efficacy for PNF exercises (−1.26, 95% CI: −1.81 to −0.72) in improving disability, assessed using RMDQ or ODI questionnaires. The level of certainty in the evidence, as determined by the GRADE approach, was very low to low. Conclusion These findings emphasize the importance of incorporating localized therapeutic exercises as a fundamental aspect of managing non-specific LBP. Clinicians should consider utilizing localized therapeutic exercise tailored to individual patient needs. Furthermore, further research investigating optimal exercise therapy, optimal dose of the exercises, durations, and long-term adherence is warranted to enhance the precision and efficacy of exercise-based interventions for non-specific LBP.