Preliminary prediction models for autonomic nervous system response to a cranial osteopathic technique Kim Collard A research project submitted in partial fulfilment of the requirements for the degree of Master of Osteopathy at Unitec New Zealand, 2009 Declaration Name of candidate: Kim Collard This Research Project entitled „Preliminary prediction models for autonomic nervous system response to a cranial osteopathic technique‟ is submitted in partial fulfilment for the requirements for the Unitec degree of Master of Osteopathy. CANDIDATE’S DECLARATION I confirm that: This Thesis/Dissertation/Research Project represents my own work; The contribution of supervisors and others to this work was consistent with the Unitec Regulations and Policies. Research for this work has been conducted in accordance with the Unitec Research Ethics Committee Policy and Procedures, and has fulfilled any requirements set for this project by the Unitec Research Ethics Committee. Research Ethics Committee Approval Number: 2008-848 Candidate Signature: ……….…………………………………….Date: ………………… Student number: 1112467 Table of Contents Abstract i Acknowledgements ii Preface…………………………………………………………………………………………………1 Literature Review…………………………………………………………………………………2 Chapter 1 6 Chapter 2 8 Chapter 3 11 Chapter 4 19 Chapter 5 23 Chapter 6 28 Chapter 7 42 Chapter 8 46 Chapter 9 60 Chapter 10 64 References 65 Manuscript…………………………………………………………………………………………74 Abstract 76 Introduction 77 Methods 79 Results 101 Discussion 112 Conclusion 122 References 123 Appendix 1 126 Appendix 2 127 Appendix 3 128 Appendix 4 137 Appendix 5 139 Appendix 6 151 Appendix 7 157 Appendix 8 159 Appendix 9 160 Appendices for the Research Project..………………………………………………….161 Appendix A 162 Appendix B 163 Appendix C 164 Appendix D 165 Appendix E 168 Abstract Preliminary prediction models for autonomic nervous system response to a cranial osteopathic technique Background and Objectives Osteopathy in the cranial field (OCF) is a contentious area of manual therapy. The literature base has attracted much debate, and consists of theories, anecdotal claims and limited academic research. As such, the potential mechanisms and effects of OCF remain poorly understood. Current research into the physiological effects of OCF is directed toward changes in measures of autonomic nervous system function. One cranial osteopathic technique, the CV4, is commonly claimed to increase parasympathetic activity. The aim of this study was to determine if the CV4 has the potential to increase parasympathetic nervous system activity in some individuals, to examine the notion of ‘responders’ and ‘non-responders’ to the CV4. Further, this study investigated variables from the participants’ history which predicted response to the CV4, with the objective of identifying responder characteristics in order to assist future research into the mechanisms and effects of OCF techniques. Methods Heart rate variability was measured in thirty participants during an experiment consisting of four phases: baseline, touch control, intervention (CV4) and post-intervention. The CV4 was delivered by one of three registered osteopaths who were experienced in cranial approaches. Response and non-response to the CV4 were operationally defined for the study. Changes in heart rate variability across the phases of the experiment were analysed individually for each participant to determine response or non-response to the CV4. Potential predictor variables for response were collected prior to the experiment. Following allocation of participants into response and non-response categories, logistic regression was used to determine which, if any, variables predicted response to the intervention. Results 14 participants were classified as responders, 16 participants were classified as non- responders. Logistic regression demonstrated predictive value of the variables relating to the individuals’ history of physical trauma and baseline heart rate variability to predict response. The variable height offered marginal predictive value. Conclusion Results of this study support claims that the CV4 has the potential to increase parasympathetic activity in some individuals. Short-term parasympathetic response to the CV4, determined by spectral analysis of heart rate variability, may be associated with an individual’s baseline ANS activity, history of physical trauma, and possibly height. Further research is required to refine understanding of response to the CV4, and to establish the relevance of the prediction models developed in this study. Key words Osteopathy in the cranial field; OCF; cranial osteopathy; CV4; heart rate variability; autonomic nervous system; logistic regression analysis; prediction model Acknowledgements There are so many people who have helped me along the way with this project, so a huge thank- you to: My supervisors Rob Moran and Craig Hilton (bold and italic). You guys are awesome! Your care, dedication and hard work are greatly appreciated, thank you so much for your help with my project. My brother Philip Collard, whose assistance with data analysis made my life so much easier. Handy to have a brother with expertise in statistics! Kate Milnes and Hugh McPherson, osteopaths (and friends), who provided advice and guidance in the planning stages of the project. All my data collection helpers, osteopathic practitioners and participants. Thanks for contributing your valuable time to be a part of my project, it would not have been possible without your input. And of course to my amazing support crew, who have kept me going throughout my studies; My classmates – the ‘non-guys’ who make study so much more entertaining. My dear friends, especially Felice and Camilla, who have provided me with so much support and encouragement, thank-you. Mum and Dad, who have always encouraged me to follow my inspiration (wherever that may lead) and helped in so many practical ways too. Sean; whose love, encouragement and belief in me have kept me going, and kept a smile on my face (most of the time). Thank-you so much for everything you do, and thank-you for knowing just the right time to lock my computer and stop me from working! Lastly to my beautiful girl Shani, who has been supportive and understanding beyond her years while I have been so busy writing this thesis. Thank-you Shani, your enthusiasm and appreciation remind me what is important in life! Preface This research project is divided into three parts. The first part is a literature review which outlines osteopathy in the cranial field, describes related theories and relevant research, then discusses literature supporting the methodology used in this study. The second part is a manuscript and related appendices which will be submitted for publication to the International Journal of Osteopathic Medicine. The manuscript uses the referencing style stipulated by the publisher. Due to the volume of material contained within the manuscript, it will be divided into two separate reports for publication, with the appendices made available on-line. However, for examination purposes is presented here as one report. The third section of this project is an appendix that contains documentation of ethics approval, participant information and guidelines for publication. Literature Review Contents Chapter 1 Introduction ................................................................................................................. 11 Chapter 2 A Brief Historical Background to Osteopathic Principles .............................. 12 Chapter 3 An Outline of Osteopathy in the Cranial Field ................................................... 11 3.1 Development of Theories about Osteopathy in the Cranial Field .......... 11 3.2 Possible Influences on Development of Sutherland‟s Theories ........... 13 3.3 Current Approaches to Cranial Therapy .................................................... 14 3.4 Contention around Osteopathy in the Cranial Field................................. 17 Chapter 4 Principles of Treatment Using Osteopathy in the Cranial Field ................... 19 4.1 Concepts of Subtle Motion ........................................................................... 19 4.2 A Description of the Cranial Rhythmic Impulse ........................................ 20 4.3 Cranial Dysfunction ....................................................................................... 21 4.4 Aims of Osteopathy in the Cranial Field .................................................... 22 Chapter 5 Theoretical Models Attempting to Explain the Cranial Rhythmic Impulse and Effects of Osteopathy in the Cranial Field .......................................................... 23 5.1 The Cranial Rhythmic Impulse .................................................................... 23 5.1.1 CSF Fluctuation and Changes in Intercranial Pressure .................. 24 5.1.2 The Potential Role of the Autonomic Nervous System .................... 24 5.2 Proposed Cellular Changes ......................................................................... 25 5.3 The Entrainment Hypothesis ....................................................................... 26 Chapter 6 Research into the Reported Mechanisms and Effects of Osteopathy in the Cranial Field ................................................................................................................ 28 6.1 Research on Osteopathy in the Cranial Field Utilising Patient-Oriented Outcome Measures ................................................................................................