The effect of the thoracic facet joints mobilization technique on heart rate variability

20代の健常者18名を対象に、体位変換、プラセボ手技、徒手モビライゼーション手技、ウエッジモビライゼーション手技（以下WM手技）の４実験を施行し、時間経過による変動を心電図R-R間隔の周波数解析装置で測定し、低周波（以下LF）成分、高周波（以下HF）成分を算出した。その結果LF成分はWM手技では増加せず、他の３実験で時間経過に伴い増加した。HF成分は４実験で変動が見られなかった。WM手技の効果に統計学的な有意差を認めなかったが、LF成分に明らかな抑制効果を認めた者が18名中７名（38％）存在した。WM手技でLF成分が増加しない理由は、胸椎椎間関節へのモビライゼーション刺激が胸部交感神経幹あるいは血管圧受容体に伝達され、脳幹に存在する心臓血管中枢に影響した結果、交感神経の洞結節への入力が抑制されたためと推測された。胸椎椎間関節へのモビライゼーション手技が心臓交感神経系に影響を及ぼす可能性が示唆された。The purpose of this study was to examine the effects of facet joints mobilization of the middle thoracic spine on the heart rate variability. Eighteen healthy volunteers underwent power spectral analysis of ECG under 4 experimental conditions including control experiment, placebo experiment, manual mobilization experiment, and wedge mobilization experiment. Spectral analysis using the maximum entropy method was applied to the heart rate variability extracting the power spectral density. Low frequency component（LF: 0.04-0.15 Hz）, high frequency component（HF: 0.15-0.4 Hz）was obtained during pre-treatment of 5 minutes and post-treatment of 30 minutes. Post-treatment average values of every 5 minutes were compared to pre-treatment average value for each component. In control, placebo, and manual mobilization, trend to increase LF was observed during post-treatment periods, but no significant increase was observed in wedge mobilization. High frequency component did not show significant change in all four experiments. Observation of individual pattern of each experiment revealed that 7 cases out of 18（38%）demonstrated reduced LF without change of HF. These results suggest that mechanical stimuli on thoracic facet joints produced by wedge mobilization dispatched some signal through adjacent thoracic sympathetic nerve trunk to cardiovascular center in the brain stem, resulted in a stabled cardiac sympathetic input to the sinus node