DEVELOPMENT OF A CONCUSSION ASSESSMENT INSTRUMENT

FOR THE SOUTH KOREAN SOLDIERS

by

Junbae Mun

A Dissertation Submitted in Partial Fulfillment

of the Requirements for the Degree of

Doctor of Philosophy in Human Performance

Middle Tennessee State University

December 2017

Dissertation Committee:

Dr. Minsoo Kang, Chair

Dr. Norman L. Weatherby

Dr. Ying Jin

I dedicate this dissertation to my wife, Wonwoo Choi, for her endless love,

sacrifice, and support.

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ACKNOWLEDGEMENTS

Thank you to God for your endless love and guidance, thank you to my lovely wife (Wonwoo Choi) and my children (Samuel Mun and Hyungyeom Mun) for being my family, thank you to Dr. Minsoo Kang and Dr. Brian Ragan for their never ending support, patience, and consideration during last four years, thank you to Dr. Norman L. Weatherby, and Dr. Ying Jin for being on my committee and their support, and thank you to members of Kinesmetrics laboratory

(Youngdeok Kim, James Farnsworth, Heontae Kim, and Seungho Ryu) for their great help.

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ABSTRACT

The purpose of this study was to develop and validate a practical concussion evaluation tool for the South Korean soldiers (SKS). This study was conducted in two phases. For phase 1, the English version of the current standardized assessment of concussion (SAC) was adapted for SKS by modifying and adding some items for resolving psychometric issues and considering cultural and linguistic equivalences, which led to develop the Korean version of the adapted SAC (K-SAC). The psychometric properties of the K-SAC were evaluated using an advanced measurement theory of Rasch model in a sample of healthy young adults without concussive injury. For phase 2, K-SAC was administered three times (i.e., baseline, time of injury, and after 48 hours) for the concussion and non-concussion groups, and the data collected was analyzed using a two-way repeated measured ANOVA to evaluate the validity of K-SAC in concussion assessment. The results of phase 1 indicated that the developed K-

SAC has sound psychometric properties at baseline evaluation of cognitive function in the target population. All items of K-SAC were properly contributed to measure cognitive function level of the sample. There was no ceiling effect on the K-SAC scores. The item difficulties of K-SAC covered all range of participants’ cognitive function levels, ranging from very easy to very difficult. The results of phase 2 demonstrated that the K-SAC also has a good validity for concussion assessment. There were significant mean differences in K-SAC scores between concussion and non-concussion groups at time of injury and no

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differences at baseline and after 48 hours. In concussion group, K-SAC score at time of concussion was significantly different when compared to the scores at baseline and after 48 hours. The findings of this study supports that the K-SAC can be a potential field concussion evaluation instrument for SKS. Further research will be required to validate K-SAC and improve generalizability of K-

SAC in various settings and populations.

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TABLE OF CONTENTS

LIST OF TABLES ...... viii

LIST OF FIGURES ...... ix

LIST OF APPENDICES ...... x

CHAPTER 1: INTRODUCTION ...... 1

Background ...... 1

Purpose of This Study ...... 7

Research Hypotheses ...... 8

Significance of This Study ...... 8

Limitations ...... 9

CHAPTER 2: LITERATURE REVIEW ...... 10

Concussion ...... 10

Concussion Assessment Tools ...... 21

Measurement Issues in Concussion Evaluation ...... 39

Methods to Evaluate Psychometric Properties ...... 48

Translation ...... 59

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CHAPTER 3: METHODS ...... 65

Phase 1 ...... 65

Phase 2 ...... 71

CHAPTER 4: RESULTS ...... 75

Psychometric Properties of the K-SAC (Phase 1) ...... 75

Validity of K-SAC in Concussion