Immediate effect of T2, T5, T11 thoracic spine manipulation of asymptomatic patient on autonomic nervous system response: Single-blind, parallel-arm controlled-group experiment

Purpose: Investigating the immediate effect of thoracic spinal manipulation on autonomic nervous system targeting three segments arbitrarily chosen, T2/T5/T11, compared to a sham-treatment randomised controlled group. Methods: 73 participants completed the study protocol. Paired-t test were used to compare within-group and ANOVA repeated measures for between-groups results. Subjects were randomised into a single-blind controlled trial involving two study groups: intervention group and sham treatment group. Outcome measure was the rMSSD, electronically recorded through R-R intervals, continuously registered over a period of 60 s before and 60 s after the manipulation/sham. Results: Within-group and between-group changes suggest a significant increase in rMSSD (p < 0.05) in intervention group compared to sham treatment, im- mediately after the postero-anterior thoracic HVLAT. Conclusion The result of this study suggests that thoracic OMT could affect ANS balance with a shift towards parasympathetic increase activity. Due to population sample, this study shouldn't be used for clinical application, but as a baseline for future research on the argument.