Demonstration of bilateral peripheral blood flow response to physical provocation tests including osteopathic digital pressure on vertebral segments

Despite widespread acceptance of the role of sympathetic hyperactivity in somatic dysfunction, autonomic response to osteopathic manipulative procedures (OMP) is not well understood.1 Modulation of autonomic activity following osteopathic procedures has been demonstrated by previous researchers through specific osteopathic manipulation and recording single upper extremity physiologic parameters (such as skin conductance, blood flow, perfusion, etc.). These data are usually recorded unilaterally. The goal of the present study is to demonstrate changes in upper extremity peripheral vasculature following a series of controlled physical provocations such as vascular occlusion, as well as digital pressure applied to select vertebral locations by an osteopathic physician. The present study leverages its development of a multi-channel signal acquisition and analyses set up to record peripheral vascular signals bilaterally over extended periods of time. To assess peripheral vascular effects from controlled physical stimuli on normal human body, instrumentation capable of multi-channel physiologic signal acquisition was used (Biopac™). Physiologic parameters representative of peripheral vascular perfusion of upper extremities such as Photo-Pulse Plethysmogram (PPG) and Laser Doppler Flow (LDF) were recorded. The acquisition was triggered by the subject's EKG signal, providing 5 channels of physiologic data. Following Institutional Review Board approval, 8 normal subjects with no clinically obvious pathologies or symptoms were tested over 15 sessions (7 control sessions). Subjects lay supine, the PPG and LDF sensors were attached bilaterally to the index and middle fingers, respectively. Standard 3-lead EKG electrodes were attached on the subjects. Physical stimulus included a transient forearm vascular occlusion for 180 s to demonstrate a post-occlusive hyperemic response. In addition, controlled digital pressure was applied by an experienced osteopathic physician sequentially, on OA-C2, T1-T4, T8-L2, and L5-S vertebral regions. These maneuvers were interspersed by quiescent phases (10 min), wherein the subject was lying undisturbed. Physiologic signals were acquired continuously during the course of the session (90–120 min). In this pilot study, quantitative change in the peripheral perfusion characteristics (PPG or LDF), is observed in all subjects during one or more vertebral pressure applications by the osteopathic clinician, compared to the quiescent unperturb