Corticomotor reorganization during short‐term visuomotor training in the lower back: A randomized controlled study

Abstract

Introduction Accumulating evidence suggests that motor skill training is associated with structural and functional reorganization of the primary motor cortex. However, previous studies have focussed primarily upon the upper limb, and it is unclear whether comparable reorganization occurs following training of other regions, such as the lower back. Although this holds important implications for rehabilitation, no studies have examined corticomotor adaptations following short‐term motor training in the lower back. Method The aims of this study were to (a) determine whether a short‐term lumbopelvic tilt visuomotor task induced reorganization of the corticomotor representations of lower back muscles, (b) quantify the variability of corticomotor responses to motor training, and (c) determine whether any improvements in task performance were correlated with corticomotor reorganization. Participants were allocated randomly to perform a lumbopelvic tilt motor training task ( n = 15) or a finger abduction control task involving no lumbopelvic movement ( n = 15). Transcranial magnetic stimulation was used to map corticomotor representations of the lumbar erector spinae before, during, and after repeated performance of the allocated task. Results No relationship between corticomotor reorganization and improved task performance was identified. Substantial variability was observed in terms of corticomotor responses to motor training, with approximately 50% of participants showing no corticomotor reorganization despite significant improvements in task performance. Conclusion These findings suggest that short‐term improvements in lower back visuomotor task performance may be driven by changes in remote subcortical and/or spinal networks rather than adaptations in corticomotor pathways. However, further research using tasks of varying complexities and durations is required to confirm this hypothesis.

Effects of different modalities of afferent stimuli of the lumbo‐sacral area on control of lumbar paravertebral muscles

“…Second, paravertebral muscle MEPs are difficult to elicit with the muscle at rest and require muscle activation (Ferbert et al, 1992; O'Connell et al, 2007; Strutton et al, 2005; Tsao, Danneels, & Hodges, 2011a). Third, in contrast to distal muscles, practice of skilled movements and neuromuscular electrical stimulation have little impact on corticospinal and/or cortical excitability of back muscles (Cavaleri et al, 2020; Elgueta‐Cancino et al, 2019). Together, these results suggest the cortical contribution to the control of paravertebral muscles is smaller than for distal upper limb muscles.…”

Can training of a skilled pelvic movement change corticomotor control of back muscles? Comparison of single and paired‐pulse transcranial magnetic stimulation

“…Tilt of the pelvis in the sagittal plane was estimated from the change in vertical acceleration (due to gravity) induced by change in tilt of the sensor. This was displayed as line on the visual feedback using Spike2 software (Cavaleri et al, 2020). To train the participants in the skilled motion of the pelvis, they initially followed a 'target' sinusoidal wave presented along with the accelerometer data.…”

“…Participants were given a 30-s rest prior to commencing the training. During training, the target curve was presented for 5 min, with the variation of the peak-to-peak amplitude with each cycle (Cavaleri et al, 2020). Participants were instructed to tilt their pelvis to match the target wave as accurately as possible (illustrated in Figure 1b).…”

The Effects of Visuomotor Training on the Functional Recovery of Post-Surgery Musculoskeletal Conditions: A Randomized Controlled Trial

“…Visuomotor training can be defined as any training or practice that integrates visual perception with motor performance. This training is able to induce changes in remote subcortical and/or spinal networks rather than adaptations in corticomotor pathways [22]. The visuomotor training has been effectively implemented in the treatment for the functional recovery of post-stroke subjects [20] as well as in athletes [23,24] and children with autism [25]; moreover, it was shown to improve function of lower back muscles [22].…”

“…This training is able to induce changes in remote subcortical and/or spinal networks rather than adaptations in corticomotor pathways [22]. The visuomotor training has been effectively implemented in the treatment for the functional recovery of post-stroke subjects [20] as well as in athletes [23,24] and children with autism [25]; moreover, it was shown to improve function of lower back muscles [22]. The extent of corticomotor plasticity and motor learning induced by complex visuomotor tasks was similar in young and old adults [26].…”