Trunk resistance to mechanical perturbations, associations with low back pain, pain-related cognitions and movement precision

Hum Mov Sci. 2023 Nov 16;92:103159. doi: 10.1016/j.humov.2023.103159. Online ahead of print.ABSTRACTBACKGROUND: Pain-related cognitions are associated with motor control changes in people with chronic low-back pain (CLBP). The mechanism underlying this association is unclear. We propose that perceived threat increases muscle-spindle-reflex-gains, which reduces the effect of mechanical perturbations, and simultaneously decreases movement precision.AIM: To evaluate effects of CLBP and pain-related cognitions on the impact of mechanical perturbations on trunk movement, and associations between these perturbation effects and movement precision.METHODS: 30 participants with CLBP and 30 healthy controls, performed two consecutive trials of a seated repetitive reaching task. During both trials participants were warned for mechanical perturbations, which were only administered during the second trial. The perturbation effect was characterized by the deviation of the trajectory of the T8 vertebra relative to the sacrum. Trunk movement precision was expressed as tracking error during a trunk movement target tracking task. We assessed pain-related cognitions with the task-specific 'Expected Back Strain'-scale (EBS). We used a two-way-Anova to assess the effect of Group (CLBP vs back-healthy) and dichotomized EBS (higher vs lower) on the perturbation effect, and a Pearson's correlation to assess associations between perturbation effects and movement precision.FINDINGS: Higher EBS was ass...
Source: Human Movement Science - Category: Neurology Authors: Source Type: research