A systematic review on the effectiveness of motor control exercise in improving morphology of lumbar multifidus muscles in patients with low back pain

Abstract

Introduction: Since low back pain (LBP) patients demonstrate morphological changes in lumbar multifidus muscles (LMM), motor control exercises (MCE) are used to improve LMM morphology and LBP. No relevant systematic reviews have summarised these findings. Therefore, this review aimed to summarise the evidence regarding the effectiveness of MCE in improving LMM morphology in LBP patients, and the temporal relationships between changes in LMM morphology and changes in LBP/LBP-related disability. Materials and Methods: Comprehensive search of CINAHL, MEDLINE, Cochrane Central Register of Controlled Trials, PEDro, EMBASE and SPORTDiscus was conducted from inception to 30 October 2019. Randomised controlled trials (RCTs) addressing our objectives were included. Methodological quality of the included studies was evaluated by the PEDro scale. Level of evidence was graded using the criteria of Oxford Center for Evidence-Based Medicine. Results: Thirteen RCTs involving 704 participants (663 chronic and 41 acute LBP) were included. MCE with/without additional intervention increased LMM CSA (level 1b evidence). MCE was better than no treatment and other interventions in increasing LMM CSA (level 1b and 2b evidence). Inconsistent evidence was noted regarding MCE altered LMM resting thickness. MCE/ McKenzie exercise/analgesics increased LMM contracted thickness (level-2b evidence). No significant correlations were noted between post-treatment changes in LMM morphology and LBP/disability. Discussion and Conclusion: While MCE is superior to other interventions in increasing LMM CSA, there is insufficient evidence to support that changes in LMM morphology is related to changes in patients’ outcomes. Future research should investigate the optimal exercise dosages for improving LMM morphology and LBP.