Characterization of Healthy Control Group in the Development of the POWAR-TOTAL: A Test of Return to Duty Readiness Following Concussion

 

Background:

Throughout physical therapy school, I have been interested in working with the military population. Growing up in a military family and in an area heavily populated by active duty and veteran servicemembers (Norfolk, VA- Go Navy!) has fostered my passion and led me to pursue a career with this unique population. The physical and mental demands of a career in the military lends itself to particular injuries that are not as common when treating civilian caseloads. Ensuring that these servicemembers are performing at an elite level in order to maintain the safety and effectiveness of their mission is the focus of rehabilitation and recovery following injury.

My clinical rotations exposed me to different realms of the military population. My rotation at the Durham Veterans Affairs Medical Center allowed me to develop an understanding of the hardship experienced by veterans that did not receive effective care in the past. Many have been out of the service for over thirty years but still experience medical issues related to their military careers. My next rotation was at Womack Army Medical Center at Ft. Bragg, where I treated highly-conditioned active-duty servicemembers that were motivated to recover from injury and return to full duty status. Both of these rotations expanded my view of military and veteran health systems, while exposing the need for comprehensive care to prevent long-term impairments.

Completing my Doctor of Physical Therapy at the University of North Carolina has given me the opportunity to launch my career in the direction of my goal- to treat active-duty servicemembers through physical therapy intervention. Dr. McCulloch has been pivotal in expanding my view of traumatic brain injury (TBI) and clinical research in the military population through class lectures and allowing me to be a part of her current project at Ft. Bragg, the development of the Portable Warrior Test of Tactical Agility (POWAR-TOTAL). Developing this capstone project has been an extremely rewarding experience as it has opened my eyes to the processes, regulations, and requirements of military clinical research and allowed me to be involved in a project that is dedicated to the detection of prolonged impairments that could lead to chronic disability.

 

Overview:

The Department of Defense defines traumatic brain injury as a “head injury (via blunt trauma or barotrauma, or both) resulting in even momentary alteration of consciousness, loss of consciousness, or posttraumatic amnesia.”¹ Servicemembers are at increased risk of TBI from combat-related exposures, routine operational and training activities, and sports and leisure activities.² Despite increased exposure to blast injuries related to combat, majority of brain injuries in servicemembers are sustained in non-combat settings most commonly as a result of training activities. 82.4% of these brain injuries are mild TBIs, also known as concussions.³ Following mTBI, a variable range of symptoms may occur related to sensorimotor, cognitive, and physical impairments from primary or secondary injuries. These body structure and function related symptoms include dizziness, headaches, imbalance, tinnitus, hearing loss, impaired cognitive processing, dysexecutive syndrome, musculoskeletal pain, and comorbid stress symptoms.¹ These symptoms can negatively impact a soldier’s performance, consequently affecting their readiness to return to duty following mTBI.

Dual-task activities involve the performance of two tasks simultaneously, requiring proper allocation of attention and executive control. Evidence indicates that impairments in dual-task performance may persist several months post-injury, despite adequate performance on each task individually. Subtle impairments may be revealed during dual-task assessments, indicating incomplete recovery following mTBI. This may translate into impaired marksmanship, degraded situational awareness, distraction, prolonged reaction times, and other performance deficits in the field. Soldiers performing at less than superior levels place themselves and their entire unit at danger.¹

 

Statement of Need:

Previously, the determination of duty-readiness following mTBI was through self-report of resolution of symptoms and improvement of isolated impairments.However, self-report is often unreliable in the military population due to high prevalence of underreporting of symptoms to accelerate return to duty (RTD). This is often perpetuated by military culture, which could increase the risk of postconcussion syndrome, increase the likelihood of secondary exposure, and place the unit at greater risk.¹ Due to these factors, clinicians are challenged to objectively assess the wide range of mTBI-associated impairments that impact readiness to RTD.⁴  Many clinical measures utilized for this purpose are prone to ceiling effects in this population due to the high performance levels of military servicemembers, often described as tactical athletes. In addition, these measures are often validated in civilian populations such as adolescents or older adults, which are very different from military personnel.^1,4

The Assessment of Military Multitasking Performance (AMMP) was developed as a measure to examine readiness to return to duty in servicemembers. It consists of functional dual-task and multitask assessments designed to challenge and uncover related vulnerabilities following mTBI.While the AMMP provided strong face validity and limits ceiling effects found in other assessments, a measure with improved clinical feasibility was needed.²

Dr. McCulloch is currently leading a DoD-funded study, the Portable Warrior Test of Tactical Agility (POWAR-TOTAL), that aims to validate this clinical test of tactical agility for active duty servicemembers recovering from mTBI. The long-term goal of this project is to provide clinicians with clinically feasible military testing measures that can assist in return-to-duty decisions following concussion. The POWAR-TOTAL requires less time, space, and expensive technology than the AMMP, while still incorporating the most sensitive and provocative aspects of tasks included in the AMMP. Furthermore, immediate feedback is provided to the clinician regarding patient status, aiding in the determination of RTD. My role in this project and the primary objective of my capstone was to characterize and measure performance of the healthy control group in order to develop an understanding of prioritization of motor vs. cognitive tasks, referred to as dual-task cost, during the POWAR-TOTAL assessment. This information will provide further validation for this measure, as well as a comparison for active-duty subjects with mTBI.

 

Products:

Throughout the fall and spring semester of my third year, I assisted Dr. McCulloch in data-quality checks for both the healthy control and mTBI groups for the POWAR-TOTAL study. For my capstone project, I characterized the healthy control group in order to understand how healthy active-duty servicemembers prioritized motor vs. cognitive tasks during a dual-task assessment. This information will be compared and examined for statistical significance with the mTBI group. I submitted an abstract and presented a poster presentation at UNC’s Human Movement Science Research Symposium in March. In addition, I have submitted an abstract and applied for a poster presentation at the Military Health System Research Symposium, which occurs in August of this year.

 

“Characterization of Healthy Control Group in the Development of the POWAR-TOTAL: A Test of Return to Duty Readiness Following Concussion”

 

Abstract

Poster Presentation

 

Evaluation:

While creating my poster, I utilized the UNC Health Sciences Library website for tips on poster design and presentation. In addition, I also viewed NYU Libraries “Poster Basics” page to gather more information about designing a poster. Before presenting my poster at HMSC, I watched multiple YouTube videos that prepared me to present an effective poster presentation. I sought feedback almost daily from Dr. McCulloch’s PhD student and a member of my capstone committee, Julianna Prim, MS. Julianna was always available to answer any questions or assist with analysis when needed. Dr. McCulloch also provided ample feedback and advice regarding the contents and layout of my poster. Additionally, I discussed my findings and received feedback about my final product from Amy Cecchini, PT, DPT, who is the project manager at the Intrepid Spirit Center- Ft. Bragg. Dr. McCulloch, Julianna Prim, and Amy Cecchini were all members of my capstone committee and contributed greatly to the success of my project.

 

Self-Reflection:

I chose this project for my capstone with the goal of furthering my knowledge of mTBI in the military population, prognostic indicators for post-concussion syndrome, and assessment techniques utilized by military clinicians following mTBI. In addition to meeting these goals, I gained valuable experience related to clinical research, including data analysis, IRB approval process, abstract writing, and presenting posters at research conferences.

Throughout my time in the DPT program, I’ve been intimidated by the elusive “capstone project” that seemed to become increasingly frightening as my final spring semester approached. After confirming the details of my project in January, I remember feeling overwhelmed about the thought of performing data analysis for healthy controls, as this was something I had never done. With the help of all members of my committee, I grew to understand the methods of for analyzing data and uncovering correlations and information from the collected data. This project brought my understanding of clinical research to a new level, and I’m very grateful for the experience.

 

Acknowledgements:

I would like to thank Dr. McCulloch for allowing me to assist with this study and providing valuable feedback regarding my capstone products. I’m incredibly grateful for the opportunity to submit and potentially present this information at MHSRS in August, as well as HMSC day last March. Thank you to Julianna Prim, who has been readily available to answer my lists of questions, while providing the calmness that I needed in my moments of stress. I would also like to thank Amy Cecchini, for giving me insight on recruitment and testing in a clinical setting and for providing helpful feedback regarding my final products. Lastly, I want to thank Larysa Petrenko, for sitting next to me three years ago in lab. I truly enjoyed working on this project with you.

 

 

References:

1. Scherer MR, Weightman MM, Radomski MV, Davidson LF, McCulloch KL. Returning service members to duty following mild traumatic brain injury: exploring the use of dual-task and multitask assessment methods.  Ther.2013;93(9):1254-1267. doi:10.2522/ptj.20120143.
2. Weightman MM, McCulloch KL, Radomski MV, et al. Further development of the assessment of military multitasking performance: iterative reliability testing. PLoS ONE2017;12(1):e0169104. doi:10.1371/journal.pone.0169104.
3. McCulloch KL, Cecchini AS, Radomski MV, et al. Military-Civilian Collaborations for mTBI Rehabilitation Research in an Active Duty Population: Lessons Learned From the Assessment of Military Multitasking Performance Project.  Head Trauma Rehabil.2017;32(1):70-78. doi:10.1097/HTR.0000000000000272.
4. Prim JH, Favorov OV, Cecchini AS, Scherer MR, Weightman MM, McCulloch KL. Clinical Utility and Analysis of the Run-Roll-Aim Task: Informing Return-to-Duty Readiness Decisions in Active-Duty Service Members.  Med.2019. doi:10.1093/milmed/usy425.

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