Neuromechanical responses after biofeedback training in participants with chronic low back pain: an experimental cohort study.

OBJECTIVE

The objective of this study was to evaluate changes in neuromechanical responses and clinical outcomes in chronic low back pain participants after 4 sessions of biofeedback training.

METHODS

Twenty-one participants took part in an electromyography biofeedback 4-session training program aimed at reducing lumbar paraspinal muscle activity during full trunk flexion. The sessions consisted of ~46 trunk flexion-extension divided into 5 blocks. The effects of training blocks and sessions on lumbar flexion-relaxation ratio and lumbopelvic ranges of motion were assessed. Changes in disability (Oswestry Disability Index), pain intensity (numerical rating scale), and fear of movement (Tampa Scale for Kinesiophobia) were also evaluated.

RESULTS

Analyses of variance revealed a significant block effect for which an increase in the flexion-relaxation ratio and the lumbar range of motion between block 1 and the other blocks for sessions 1 and 2 (P < .0001) was observed. However, no significant session or interaction effect was observed. Among clinical outcomes, only fear of movement significantly decreased between the baseline (mean [SD], 33.05 [7.18]) and the fourth session (29.80 [9.88]) (P = .02). There was no significant correlation between clinical outcomes and neuromechanical variables.

CONCLUSION

Biofeedback training led to decreases in lumbar paraspinal muscle activity in full trunk flexion and increases in lumbopelvic range of motion in participants with chronic nonspecific low back pain. Although the neuromechanical changes were mostly observed at the early stage of the program, the presence of a decrease in the fear of movement suggests that the participants' initially limited ROMs may have been modulated by fear avoidance behaviors.