Effects of spinal stabilization exercise with real-time ultrasound imaging biofeedback in individuals with chronic nonspecific low back pain: a pilot study

The use of real-time ultrasound imaging (RUSI) as biofeedback to enhance the performance of spinal stabilization exercise and recovery from low back pain has been a recent trend in musculoskeletal rehabilitation. The aim of this pilot study was to evaluate whether it would be feasible to conduct a randomized controlled trial investigating the effects of spinal stabilization exercise with RUSI biofeedback in individuals with chronic nonspecific low back pain. This was a single-group pretest-posttest quasi-experimental study. Ten consecutive patients with chronic nonspecific low back pain met the study criteria. They received spinal stabilization exercise with the RUSI biofeedback focusing on lumbar multifidus muscle activation. The intervention was provided twice weekly for 6 weeks. Outcome measures were lumbar multifidus muscle cross-sectional area, pain, disability and quality of life assessed at baseline and after intervention. A paired t-test was applied and effect size (Cohen d) was computed. The recruitment and retention rates were 75% and 83% respectively. No adverse events were reported during the study. Compared with the baseline, the participants demonstrated statistically significant improvement in lumbar multifidus muscle cross-sectional area (P<0.05, d=1.03), pain (P<0.001, d=2.56) and disability (P<0.05, d=1.43) with large effect size after the intervention. However, no statistically significant differences were observed for physical and mental health (P>0.05) after the intervention. It was concluded that spinal stabilization exercise with RUSI biofeedback is effective in improving lumbar multifidus muscle cross-sectional area, pain and disability in individuals with chronic nonspecific low back pain. The results demonstrated the feasibility of conducting a future, larger-scale powered randomized controlled trial to confirm these preliminary findings.