Autonomic correlates of osteopathic manipulative treatment on facial functional mapping: an innovative approach based on thermal imaging

Osteopathic manipulative treatment (OMT) has shown efficacy in various clinical conditions and age groups. Understanding its neurobiological, particularly autonomic, mechanisms of action remain limited. Preliminary studies suggested a parasympathetic effect of OMT, evidenced by heart-rate-variability analysis. A cross-over RCT on healthy adults was conducted to compare OMT with sham therapy. Thirty-seven participants underwent two sessions (OMT and sham), comprising baseline, tactile treatment, and post-touch. Novel thermal imaging data analyses in combination with seed correlation analyses (SCA) were employed to explore the OMT effects on autonomic parameters. Particularly, the sham group exhibited an elevated warming effect on the cheeks, nose, and chin. Inversely, for the OMT group a conspicuous cooling trend in the nose, but not in the cheeks and chin was observed. Considering SCA maps, the intensity of the correlation for nose tip, glabella and GSR seeds showed higher values in the OMT compared to the sham group. The comparative analysis of thermal maps and SCA results represents a significant advancement in our understanding of the physiological mechanisms underlying OMT's effects on autonomic functions. By elucidating specific patterns of temperature change, correlation intensity and specific clusters, this research provides valuable insights for optimizing clinical practice and refining theoretical models of manual therapy.