Associations among lumbopelvic muscle activation, functional capacity, and self-reported clinical outcomes in individuals with chronic low back pain: A cross-sectional study

Background: Lumbar multifidus (LM) and transverse abdominis (TrA) muscle activation deficits have been reported in patients with chronic low back pain (CLBP). These activation deficits could be related to poor functional capacity and self-reported clinical outcomes. Objective: To determine the associations between lumbopelvic muscle activation and functional capacity, as well as self-reported clinical outcomes in individuals with CLBP. Methods: Thirty individuals with CLBP were recruited. Ultrasound imaging was used to measure muscle activation. Participants performed a functional reach test (FRT), 5-time sit-to-stand test (5STS), 2-min step test (2MST), prone trunk extension test (PTET), and abdominal curl test (ACT). Self-reported clinical outcomes including visual analog scale (VAS), duration of low back pain (DLBP), modified Oswestry disability questionnaire (MODQ), and short-form health survey (SF-36) were also collected. Results: LM activation was significant associated (P < 0.05) with functional capacity (5STS and PTET) and self-reported clinical outcome (SF-36) were observed. Results also demonstrated TrA activation was significant associated (P < 0.05) with ACT, VAS, and DLBP. Conclusion: Our findings suggest that clinicians should focus on LM activation to potentially improve functional capacity and quality of life, as well as minimize the chronicity. In addition, pain duration can influence TrA activation, while TrA activation training may be able to modulate pain.