Comparative analysis of the autonomic nervous system response during movement representation in healthy individuals and patients with chronic low back pain: a prospective cohort study.

ABSTRACT

OBJECTIVE: The primary objective was to compare the difference in autonomic nervous system (ANS) response between motor imagery (MI) group and action observation (AO) group. Both consisted of two subgroups the control subgroup (CG), which consisted of asymptomatic individuals, and the patient subgroup (PG), which consisted of patients with chronic low back pain (CLBP). The secondary objective was to assess ANS activity during AO and MI training according to the fear-of-movement levels of the PGs. METHODS: Sixty participants were randomly assigned. The autonomic outcome measures included skin conductance (SC), respiration rate (RR), and heart rate (HR). RESULTS: Results showed that intergroup differences in RR were higher in the PG, with a large effect size (p = .007, d = 1.71). Only the PGs showed intragroup differences in SC (p <.05). In terms of ANS activity during the training, there were no statistically significant intergroup differences (p <.05). However, the strongest intragroup differences were among the AOPG with greater levels of kinesiophobia. For the SC and HR variables, only this condition showed significant differences between baseline and the first and second movements, with a large effect size (p <.001 and p = .002, respectively, and d >.80). CONCLUSIONS: The results showed that AO and MI training in the PG and CG resulted in similar but not identical ANS activation, with slightly higher activation in the PG. The differences in the PG could be associated with kinesiophobia when visually exposed to low-back movements that could be interpreted as hazardous or unsafe.