Background & Aims

Transcranial magnetic stimulation (TMS) has revealed differences in the motor cortex (M1) between people with and without low back pain (LBP) (1, 2). There is potential to reverse these changes using motor skill training (3). Although earlier studies found no effect of back muscle training on TMS measures in healthy individuals (4), it remains unclear whether changes can be induced in people with LBP or whether this differs between LBP subtypes (i.e., nociceptive and nociplastic pain). This study aimed to (1) compare TMS measures of M1 and performance of a motor task between individuals with LBP of predominant nociceptive or nociplastic presentation; (2) compare these measures pre- and post-training; and (3) explore correlations between TMS measures, motor performance, and clinical features.

Methods

Eighteen participants with LBP (9 nociceptive, 9 nociplastic) trained a lumbopelvic motor learning task for three 5-minute blocks. Single- and paired-pulse TMS measures were undertaken pre- and post-training. Data were compared with 16 pain-free individuals from a prior study.

Results

TMS measures did not differ between groups at baseline. The nociplastic group undershot the target in the motor task. Despite improved motor performance for all groups, only MEP amplitudes increased across the recruitment curve and only for the pain-free and nociplastic groups. Baseline or change in TMS measures did not correlate with motor performance or clinical features.

Conclusions

Some elements of motor task performance and changes in corticomotor excitability differed between LBP groups. Absence of changes in intra-cortical TMS measures suggests regions other than M1 are likely to be involved in skill learning of back muscles.

References

1. Strutton, P. H., Beith, I. D., Theodorou, S., Catley, M., McGregor, A. H., & Davey, N. J. (2004). Corticospinal activation of internal oblique muscles has a strong ipsilateral component and can be lateralised in man. Exp Brain Res, 158(4), 474-479.

2. Massé-Alarie, H., Beaulieu, L. D., Preuss, R., & Schneider, C. (2016). Corticomotor control of lumbar multifidus muscles is impaired in chronic low back pain: concurrent evidence from ultrasound imaging and double-pulse transcranial magnetic stimulation. Exp Brain Res, 234(4), 1033-1045.

3. Hall, L., Tsao, H., MacDonald, D., Coppieters, M., & Hodges, P. W. (2009). Immediate effects of co-contraction training on motor control of the trunk muscles in people with recurrent low back pain. J Electromyogr Kinesiol, 19(5), 763-773.

4. Shraim, M. A., Massé-Alarie, H., Salomoni, S. E., & Hodges, P. W. (2022). Can training of a skilled pelvic movement change corticomotor control of back muscles? Comparison of single and paired-pulse transcranial magnetic stimulation. Eur J Neu, 56(1), 3705-3719.

Presenting Author

Muath A Shraim

Poster Authors

Muath Shraim

BPhty, PhD

University of Queensland

Lead Author

E-mail

Topics

  • Mechanisms: Biological-Systems (Physiology/Anatomy)