CORE Metadata, citation and similar papers at core.ac.uk Provided by University of Oregon Scholars' Bank MEASURING HUMERAL HEAD TRANSLATION AFTER SUPRASCAPULAR NERVE BLOCK by BERNARDO G. SAN JUAN JR. A DISSERTATION Presented to the Department of Human Physiology and the Graduate School ofthe University of Oregon in partial fulfillment ofthe requirements for the degree of Doctor ofPhilosophy September 2009 11 University of Oregon Graduate School Confirmation of Approval and Acceptance of Dissertation prepared by: Bernardo San Juan Title: "Measuring Humeral Head Translation After Suprascapular Nerve Block" This dissertation has been accepted and approved in partial fulfillment ofthe requirements for the Doctor ofPhilosophy degree in the Department ofHuman Physiology by: Andrew Karduna, Chairperson, Human Physiology Li-Shan Chou, Member, Human Physiology Louis Osternig, Member, Human Physiology Stephen Frost, Outside Member, Anthropology and Richard Linton, Vice President for Research and Graduate Studies/Dean ofthe Graduate School for the University of Oregon. September 5, 2009 Original approval signatures are on file with the Graduate School and the University of Oregon Libraries. III © 2009 Bernardo G. San Juan Jf. IV An Abstract ofthe Dissertation of Bernardo G. San Juan Jr. for the degree of Doctor ofPhilosophy in the Department of Human Physiology to be taken September 2009 Title: MEASURING HUMERAL HEAD TRANSLATION AFTER SUPRASCAPULAR NERVE BLOCK Approved: Andrew R. Karduna, PhD Subacromial impingement syndrome is the most common disorder ofthe shoulder. Abnormal superior translation ofthe humeral head is believed to be one ofthe major causes ofthis pathology. The overall purpose ofthis study was to better understand glenohumeral kinematics in normal healthy individuals using fluoroscopy to help comprehend the mechanism ofshoulder impingement. This research was divided into three sections: a validation study to measure humeral head translation, a comparison between dynamic and static arm elevation and lastly, humeral head translation after a suprascapular nerve block. In the first study, fluoroscopy was used to take images ofhuman cadaver shoulders. Scapular orientation was manipulated in different positions while the humerus was at 90 degrees of elevation. Humeral head translation was measured using two v methods and was compared to the known translation. Additionally, the accuracy ofthe contour registration method to measure 2-D scapular rotations was assessed. For the second study, subjects elevated their dominant arm while fluoroscopic images were taken. An edge detection software was utilized to digitize points on both the humeral head and glenoid. Humeral head translation and scapular upward rotation were measured using a contour registration method with respect to the glenoid during arm elevation. Five different arm elevation angles were investigated to measure differences in humeral head translation between trials. There was no difference found between humeral head translation and scapular upward rotation between static and dynamic shoulder elevation. For the third study, humeral head translation was measured before and after a suprascapular never block. The humeral head was superiorly located and the scapula was more upwardly rotated after the block. The differences were observed during mid range ofmotion. This result showed that there was a compensatory increase in both humeral head translation and scapular upward rotation due to the nerve block. These results suggest that increasing muscular strength and endurance ofthe supraspinatus and infraspinatus muscle could prevent any increased superior humeral head translation. This may be beneficial in preventing shoulder impingement or rotator cufftear over time. This dissertation includes unpublished co-authored materials. VI CURRICULUM VITAE NAME OF AUTHOR: Bernardo G. San Juan Jr. PLACE OF BIRTH: Marikina City, Philippines DATE OF BIRTH: May 4,1977 GRADUATE AND UNDERGRADUATE SCHOOLS ATTENDED: University ofOregon San Diego State University University ofthe Philippines, Diliman DEGREES AWARDED: Doctor ofPhilosophy, 2009, University of Oregon Master ofArts, 2003, San Diego State University Bachelor of Science, 2000, University ofthe Philippines, Diliman AREAS OF SPECIAL INTEREST: Sports Medicine and Human Performance PROFESSIONAL EXPERIENCE: Graduate Teaching Fellow, Department ofHuman Physiology, University of Oregon, Eugene, 2004 - 2009 Graduate Research Fellow, Department ofHuman Physiology, University of Oregon, Eugene, 2004 - 2009 Adjunct Faculty, School ofHealth, Physical Education, and Athletics, Southwestern Community College, Chula Vista, CA, 2003 - 2004 National Athletic Trainer's Association, Certified Athletic Trainer, 2005 Vll GRANTS, AWARDS AND HONORS: Ursula (Sue) Moshberger Endowed Scholarship, Travel Grant, 2008 PUBLICATIONS: San Juan, JG., Karduna, AR: Measuring humeral head translation using fluoroscopy: A validation study. Journal ofBiomechanics. In review, 2009. San Juan, JG., Yaggie, JA., Levy, S., Mooney, V., Udermann, BE., Mayer, JM: Effects ofpelvic stabilization on lumbar muscle activity during dynamic exercise. Journal ofStrength and Conditioning Research. 19(4): 903-7, 2005. V111 ACKNOWLEDGMENTS .. I would like to express my deepest gratitude to my mentor Dr. Andrew Karduna for all his guidance and patience in my entire stay here at the University ofOregon. It was a privilege working and learning under his tutelage. I am very blessed ofhaving Andy as my advisor. He taught me how to be a critical thinker and a problem solver. Andy helped me better understand what a sound research should be. In addition, he was the best player in our softball intramural team. Ifnot for him our team will be disorganized. I would like to thank Dr. Lou Osternig, Dr. Li-Shan Chou and Dr. Stephen Frost for all the insight they gave me in formulating and conducting my research. They all play an important role in making this a sound research study. Dr. Osternig was instrumental in reminding me about the clinical significance ofmy research. Moreover, he thoroughly inspected and recommended improvements for my manuscript. Dr. Chou was very helpful in making sure my protocol was proper for all my research study and how to appropriately analyze my data. I would like to thank Dr. Frost for sharing his expertise in the different techniques used in contour recognition in his field. I enjoyed all the meetings I had with everyone ofyou. I would like to thank my lab mates: Dave, Tal, Luke, Carl, Tola and Vamsi for all their help and support in data collection and for all the insights they gave me to make my research better. You guys made my stay here at the University of Oregon worthwhile. In addition, I would like to extend my gratitude to: Linden, Anni, Meagan, Mikey, Lindsey IX and Amanda for all their extra time and hard work in helping me collect and analyze the data. Ifnot for them I will not be done with my degree by now. I would like to thank Dianne Raponi for assisting in the data collection and Dr. Peter Kosek for the use ofthe fluoroscopy machine and performing the nerve block procedure. Ifnot for Dianne I would not be able to acquire quality fluoroscopic images. Dr. Kosek was very kind in taking time to perform the nerve block procedure with his busy schedule. Also, Mark Dow for developing the Space software I used to analyze my data. I would also like to thank all my friends: Eric, Cindie, Brent, Molly, and Vipul for all the support they gave me. They always made sure that I am in track in finishing my degree. Thanks for all the time we spent hiking and golfing that helped relieved my stress. I would like to thank my Aunt Luz and Lita, Uncle Dave and Gary, and my cousin Leo for helping me adjust to a new environment. They are always there to comfort me, and they always believe in me. Thanks for always being there for me. Most importantly, I would like to thank my family for all their support. I dedicate this degree to my parents who I know are always present and looking over me and guiding me through all my endeavors. Also special thanks to my sister, Normie, who is always there for me to hear my complaints about life and school and for all her support and guidance. This research was supported by NIOSH grant # 5ROI OH008288. x TABLE OF CONTENTS Chapter Page I. INTRODUCTION 1 Intrinsic Factors 3 Extrinsic Factors 5 Specific Aim and Hypotheses 9 Bridge ; 10 II. MEASURING HUMERAL HEAD TRANSLATION USING FLUOROSCOPY: A VALIDATION STUDY 12 Introduction 12 Methods 13 Specimens and Instrumentation 13 Protocol 14 Image Analysis 15 Results 17 Discussion 19 Bridge 20 III. MEASURING IN-VIVO HUMERAL HEAD TRANSLATION USING FLUOROSCOPY: A COMPARISON OF STATIC AND DYNAMIC POSITIONING 22 Introduction 22 Methods 24 Subjects 24 Protocol 25 Kinematic Measurement 28 Data Analysis 30 Results 30 Discussion 33 Conclusions 35 Bridge 35 IV. HUMERAL HEAD TRANSLATION AFTER A SUPRASCAPULAR NERVE BLOCK 36 Introduction 36 Materials and Methods 38 Statistical Analysis 47 Results 49 Xl Chapter Page Force Measurement 49 Glenohumeral Translation and Scapular Upward Rotation 50 EMG Muscle Activation 50 Discussion 53 V. CONCLUSIONS AND RECOMMENDATIONS 57 Strength ofthe Study 60 Limitations ofthe Study 61 Recommendations for Future Research 62 APPENDICES 64 A. CONSE:t\TT FORM STlTDY 2 : 64 B. CONSENT FORM STlTDY 3 67 C. SUBJECT INTAKE FORM 71 REFERENCES 72 XlI LIST OF FIGURES Figure Page 2.1. Shoulder Jig 14 2.2. Digital image with points and digitized contours 17 2.3. Superior translation RMS error between the two methods 18 3.1. Subject set-up with the customized elevation guide 27 3.2. Digital x-ray image with a representation ofdigitized points 29 3.3. The difference between static and dynamic conditions in measured humeral head translation during the non-weighted trial 31 3.4. The difference between static and dynamic conditions in scapular upward rotation during the non-weighted trial 31 3.5. The difference between static and dynamic conditions in measured humeral head translation during the weighted trial 32 3.6. The difference between static and dynamic conditions scapular upward rotation during the weighted trial 32 4.1.