Principal Investigator: Andrew C. Smith, PT, DPT, PhD

Title: Epidural Stimulation to Restore Voluntary Function after Spinal Cord Injury: Responders and Real-World Effectiveness

Abstract: 

Spinal cord injury (SCI) is a devastating event in terms of a person’s health, physical function, costs (direct and indirect), and life expectancy. It has been conventionally thought that individuals with severe SCIs, with no motor function below the level of injury, will not recover the ability to functionally move their lower extremities or walk. However, spinal cord epidural stimulation (scES) has emerged as a promising intervention challenging this long-held assumption. While scES allows for restored voluntary movement after severe SCI, there is a need for objective biomarkers to identify who will optimally respond to this intervention, and there is a lack of research investigating how scES impacts voluntary abilities and quality of life in the home and community. This proposal will use neuroimaging biomarkers and wearable sensors to identify which individuals will optimally respond to scES and investigate how scES affects voluntary function and quality of life in real world settings to inform “game-changing” treatment strategies for individuals with motor-complete SCI. Findings from this project will provide essential data on the effectiveness of scES in real world settings at a crucial time in this field. An improved understanding will help drive individualized approaches for using scES, and the identification of who is likely to optimally respond. Completion of the proposed aims will lead to the high likelihood of sustained, powerful influence on the scES field. This influence will lay a vital foundation for providing realistic expectations of improving voluntary functional abilities and quality of life in the home and community, using neuroimaging biomarkers to guide scES intervention.

Principal Investigator: Ann Lantagne, PhD and Christine Petranovich, PhD

Title: Solving Problems: Evaluating the Feasibility and Acceptability of Implementing an Adolescent Online Problem-Solving Group Telehealth Intervention

Abstract: Traumatic brain injuries (TBI) are considered a public health phenomenon and are a leading cause of morbidity and mortality in the United States, costing around $1 billion annually (Haarbauer- Krupa et al., 2018). Prevalence rates reach one of the highest peaks among adolescents ages 15-19 (Taylor et al., 2017), and adolescent TBI is associated with persistent psychosocial difficulties and increased family dysfunction and distress (Bloom et al., 2001; Wade et al., 2002). However, only about 10% of youth with TBI receive mental health services after injury (Karver et al., 2014; Narad et al., 2019). Amidst the COVID-19 pandemic, adolescent psychosocial difficulties increased significantly while waitlists for psychological intervention have grown to the point of declaring a mental health state of emergency in Colorado (Marques de Miranda et al., 2020). Fortunately, evidence based psychological interventions exist for adolescents post-TBI, such as the Teen Online Problem-Solving Intervention (TOPS; Wade et al., 2012), which is grounded in a cognitive behavioral approach and targets skills impacted by brain injury. However, at present, there are no evidence-based group interventions for adolescents post-TBI. Peer support is especially important due to the isolation experienced by many teens during the current pandemic as well as social isolation due to differences in behaviors, functioning, and emotions following brain injury (Racine et al., 2020). As such, the primary aim of the present proposal is to implement a telehealth group adaptation of the TOPS protocol, and to evaluate the feasibility (as measured by adherence to group treatment) and acceptability (as measured by patient and parent satisfaction and participant engagement) of the group intervention. Results of the proposed clinical research have the potential to allow our department to better serve our patients, as the availability of empirically validated group therapy options may allow for more families to be seen sooner at CHCO, reducing wait times, and potentially providing earlier intervention. Through telehealth groups, many patients who previously were unable to access group interventions due to barriers such as distance from the hospital, other childcare or work requirements, and transportation, can now be included. As such, the implications of this study are timely and address an important current clinical need in our department.

Principal Investigator: Cristina Sarmiento, MD

Title: Mind the Gap: A Mixed Methods Approach to Understanding the Rehabilitation Needs and Transition Experiences of Adults with Cerebral Palsy

Abstract: Our goal is to increase understanding of the current rehabilitation needs, transition readiness, and experiences of young adults with cerebral palsy (CP) in a novel adult CP clinic, using mixed-methods to: 1) characterize the patient population seen in terms of demographics and rehabilitation needs; 2) increase understanding regarding their rehabilitation care and transition from pediatric- to adult-based rehabilitation care; and 3) evaluate whether a widely used transition readiness questionnaire can be used to adequately evaluate transition readiness among this population. This pilot data will be used to apply for larger grants, including a Career Development Award for the PI. The long-term goal of this work is to develop an evidence-based patient- and family-centered transition process from pediatric to adult rehabilitation care for individuals with CP 

CP is one of the most common causes of childhood physical and developmental disability, and the vast majority of individuals with CP are living and thriving into adulthood. Rehabilitation care is a critical aspect of lifespan care for individuals with CP; however, the optimal transition process from pediatric- to adult-based rehabilitation care is not known. The PI is currently involved in a study focused on young adults with CP being seen in a pediatric rehabilitation clinic who have not yet transitioned. This study will help us to understand the experiences of young adults with CP being seen in an adult rehabilitation clinic who have transitioned.

2021 & Previous Years Awards

Principal Investigator: Kristin Uhler, PhD, CCC-A, PASC

Title: A novel method for improving bone conduction auditory brainstem response measures in infants

Abstract: Over twenty years ago, in the United States, Universal Newborn Hearing Screenings began, which has led to improved habilitation of infants and young children with hearing differences. These improvements have led to most children with hearing loss entering school with language within two standard deviations of their normal-hearing peers. However, there continues to be significant variability in outcomes of children with hearing loss; accurate audiologic assessment contributes to better outcomes. One challenge that persists is the accurate diagnosis of hearing loss (for example, the identification of conductive versus sensorineural pathology) which is key to effective intervention (e.g., the type of hearing aid fit and the amount of gain provided versus a cochlear implant).

During early infancy, an electrophysiology measure known as the auditory brainstem response (ABR) test assesses hearing abilities. Because screening for and identification of hearing loss is only as effective as the tools available for diagnosis, improved tools can lead to improved detection and classification of hearing loss and improved treatment outcomes. Improved accuracy of bone conduction testing is key to making sure infants receive the right type and programming for their hearing aids. Until this is done, children with hearing loss will continue to be at risk for poorer access to spoken language during a critical period of language development. We will test a novel method to reduce artifact in bone conduction testing, which is how clinical audiologists diagnose the type of hearing loss. We will compare the currently used bone conduction transducer, and Mu-Metal shielded bone conduction transducer to compare the differences in the artifact.

We hypothesize that testing with the shielded bone conduction oscillator will reduce stimulus artifact and improve the accuracy of bone conduction thresholds measured via ABR testing in infancy (1-5 months of age). We will utilize a within-subjects design to test aim 1 to compare artifacts between the shielded and unshielded bone conduction transducers. Next, we will quantify differences in waveform identification among audiologists for the shielded versus unshielded transducer. In aim 2, we will validate the accuracy of the ABR test measured during early infancy by having participants who were tested in aim 1 return for behavioral testing six months later. We will examine the threshold differences measured via ABR versus behaviorally. Differences of less than 10 dB HL at two or more frequencies will be considered good test-retest reliability. Poor reliability would result in poor hearing aid fittings and, in turn, poorer access to spoken language. The long-term goal of this research is to improve the sensitivity of diagnostic tools for ABR assessment to improve the accuracy of interventions. Improved habilitation strategies are highly relevant to the Department of Physical Medicine and Rehabilitation mission.

2020

Principal Investigator: Andrew Smith, PT, PhD 

Title: Machine learning to quantify muscle changes, lean body mass, and function in obese adults

Abstract: Just under half of Americans suffer from obesity, a condition related to heart disease, stroke, type 2 diabetes and types of cancer that can lead to preventable, premature death. Obesity is diagnosed using an
individual’s body-mass index, which is a metric that fails to account for high muscle composition versus high fat composition. A more informative anthropometric measure is Lean Body Mass (LBM), which characterizes the amount of fat-free tissue. Relationships between measures of body composition (i.e. LBM) to physical function are mediated by measures of intramuscular adipose tissue (IMAT). Elevated IMAT in obese
individuals escalates the onset and progression of sarcopenia; and thus has prompted muscle quality to be
used as a diagnostic criteria for sarcopenia. 

Although LBM is quantified using duel energy x-ray absorptiometry which exposes the patient to ionizing radiation, existing magnetic resonance imaging (MRI) is now able to accurately estimate LBM. Specifically, using only one mid-thigh MRI axial slice, thigh muscle cross-sectional area has been found to predict LBM and accurately quantify IMAT.

However, the manual measurement of MRI scans can be subjective and time-consuming, limiting the clinical applicability to estimate LBM and quantify IMAT. The ability to automate procedures to estimate LBM from existing medical imaging would provide a convenient option for clinicians to provide data-driven individualized care. Recently, convolutional neural networks (CNNs) have been reported as a viable machine-learning-based approach to rapidly and accurately measure MRI of skeletal muscle. An available CNN to provide swift quantification of LBM and IMAT and predict the functional status of obese individuals would facilitate the desired data-driven individualized care of this patient population. Accordingly, the main objective of the proposed research is to train and test a machine-learning model to automatically measure mid-thigh muscle cross sectional area to both provide rapid estimation of LBM and IMAT, and predict the functional status of obese adults. To accomplish this, we will leverage a pre-existing clinical MRI dataset from the Department of Endocrinology.

2018-2019

Principal Investigator: Michael Bade, PT, PhD 

Title: Multimodal Edema Management Program Post TKA

Abstract: Currently in the United States, more than 700,000 total knee arthroplasty (TKA) surgeries are performed annually with projections of 3.5 million performed annually by 2030.1,2   Postoperative knee swelling after TKA is profound and associated with decreased muscle activation, strength, range of motion, and functional performance as well as increased pain and post-surgical complications such as deep venous thrombosis (DVT).3-7  However, to date, traditional physical therapy interventions such as cryotherapy have demonstrated minimal effectiveness in reducing swelling and its associated sequelae.8  We have developed a novel multimodal edema management (MEM) program utilizing therapeutic exercise, compression garments, and self-administered lymphatic massage to decrease postoperative swelling.  This pilot cohort study will determine the variability and responsiveness of bioimpedance spectroscopy (primary outcome) in response to the MEM program in 15 participants after TKA.  Secondarily, we will determine the feasibility and patient perceptions of the MEM program after TKA by assessing: 1) adherence, 2)  satisfaction, and 3) safety (secondary outcomes).  Finally, we will explore the potential mechanistic relationship between postoperative swelling levels and quadriceps muscle activation deficits, strength and functional performance (secondary outcomes).  The MEM program will be delivered in the home setting in addition to standard of care rehabilitation over three weeks.  Outcomes will be assessed preoperatively and postoperatively at day 4, day 7, week 2, and week 3. Data from this study and historical swelling data of individuals after TKA (N=40) will be utilized to guide subsequent trial planning.  This study is directly related to the departmental vision of improving the health of populations seeking care from PM&R professionals as well as providing the opportunity to collect data to leverage for future funding.  Finally, our study team consist of a diverse range of health care professionals from physical therapy, occupational therapy, chiropractic, physiatry, and orthopedics.  The investigative team possess a range of research experience which create opportunities to mentor more junior investigators and clinicians.

Principal Investigator:  Mark M. Manago, DPT, PhD 

Title: Instrumented motion analysis of hip and trunk movement compensations for people with multiple sclerosis

Abstract: Difficulty walking is one of the most commonly reported problems for people with multiple sclerosis (MS) and is associated with compensatory movement patterns. Movement pattern compensations can be the result of muscle weakness and lead to painful and/or inefficient gait that affects daily walking. Movement pattern compensations for people with MS have been well-documented at the ankle and knee through instrumented motion analysis, however less is known about the hip and trunk. This is a crucial gap in knowledge, as our recent work has demonstrated that hip abduction and trunk muscle strength are key predictors of gait performance, yet few strengthening studies have targeted these muscles to improve gait. By developing a better understanding of hip and trunk movement pattern compensations during gait and understanding how these compensations relate to hip and trunk muscle weakness, we can design strength training interventions for the hip and trunk that are both targeted to the appropriate muscles and that can specifically address movement pattern compensations. In addition to improving intervention at the hip and trunk, identifying patients who might benefit from proximal strengthening is also an important priority, yet clinical assessments of proximal muscle function, such as the Trendelenburg test, have not been studied in people with MS. 

Therefore, the overall aim of this proposal is to improve understanding of hip and trunk movement pattern compensations in people with MS using instrumented motion analysis to 1) identify frontal plane compensations in the hip and trunk during gait and 2) validate the Trendelenburg test. A cross-sectional design consisting of one visit will be used. We hypothesize that instrumented motion analysis will 1) identify impairments in peak hip and trunk frontal plane moments and angles during gait, and 2) correlate with Trendelenburg angles as measured with goniometry during single-limb stance.

The results from this study would 1) be the final step in our development of a novel strengthening approach that incorporated hip and trunk muscles, and 2) improve clinical assessment of proximal muscle function in people with MS. This novel approach would have the potential to set a new standard for strength training and assessment in people with MS by addressing compensatory patterns, improving gait performance, and ultimately, increasing participation and quality of life.

Principal Investigator: Maryam Tahmasbi Sohi, MD  

Title: Short term Effects of Intraarticular Triamcinolone Acetonide Injection on Serum Testosterone, LH and FSH Levels in Cohort of Male Veterans with Osteoarthritic Glenohumeral Joint: A Prospective Pilot Study 

Abstract: Musculoskeletal disorders are among the most frequently occurring chronic conditions affecting the US population. They have a substantial impact on quality of life, use of health care resources, and the nation's economy. Physiatry, among other specialties in medicine, is commonly involved in conservative management of musculoskeletal pain through therapy, activity modification, oral pain medications, and corticosteroid injections. Utilization of ultrasound guidance has improved the accuracy and efficacy for some of these injections, but there is relatively little data on their systemic effects with long-term and frequent use. Currently there have been no prior studies on the effects of localized corticosteroid injections on gonadal-pituitary axis. The overall objective of this pilot study is to determine the changes in gonadal-pituitary axis testosterone level after an ultrasound-guided injection of standard dosing of triamcinolone acetonide into the glenohumeral joint. To do this a before-after study, we will use a mixed effects model with a random intercept. Knowledge gained supports future, more rigorous trials that are focused on how modifications in frequency and dosing will influence adverse effects and efficacy of corticosteroid injections.

Principal Investigator: Amy Bodkin, PT, PhD, Aaron Powell, MD 

Title: Validation of Gait Analysis in Children with Spina Bifida Using Plantar Pressures 

Abstract: Children with spina bifida have numerous gait deviations and are heavily reliant on therapies, bracing, equipment, and surgical intervention to achieve and maintain ambulation. Objective measurement of gait is extremely helpful for clinical decision-making, but current kinematic gait studying techniques are cost prohibitive and generally uncovered by payers. Because of this, clinical decision-making is usually based on subjective bedside clinical examination and observation of gait.

Plantar pressure (PP) measurements (which visualize pressure fields between the surface of a foot and a supporting surface) can provide information on foot position, pressure distribution, and temporal-spatial parameters (gait speed, cadence, etc.) during gait. PPs are more efficient and less expensive than conventional 3-dimensional optical motion capture (OMC). These simple measures from PP gait analysis can be used to track progression of mobility impairments and assess risk for future health conditions in individuals with movement disabilities. Objective parameters obtained through PPs have been validated in typical gait patterns, but not for individuals with atypical plantar pressures and gait (the population that could benefit most from this technology).

The aim of this proposed pilot study is to establish validity and reliability of automated PP analysis to determine foot position and resultant pressure distribution during gait in children with spina bifida. Achieving the aims of this study would directly impact health outcomes of children with spina bifida by optimizing our ability to objectively evaluate multiple domains of their abnormal gait in an accurate, efficient, and economical way. It would also allow us to apply for future funding to create standardized gait measurement techniques for children with spina bifida that will decrease costs and improve the accuracy of clinical evaluation and decision-making.

2017 Awards

Principal Investigator: Dawn Magnusson, PT, PhD 

Title: Development of a novel decision aid to improve early identification and intervention for children with developmental delay​

Abstract: In the United States (US), one in four children under the age of five years is at risk for experiencing developmental delay (DD). Early identification of DD during the well-child visit, and use of pediatric therapy services are essential for optimizing the health and well-being of children with DD. Evidence-based developmental surveillance and screening (DSS) guidelines and service recommendations are intended to support children with DD, yet such guidelines do not guarantee that children with DD will receive needed therapy services. Children from racial or ethnic minority groups, and low-income children are especially vulnerable when it comes to having their delays identified and service needs met. The mechanisms underlying these disparities are not fully understood; however, there is mounting evidence that parental health beliefs play an important role in shaping help-seeking pathways for children with DD. It may be that evidence-based guidelines and recommendations, presented during the well-child visit, use concepts and language that lack meaning among community members. The short-term objective of this project is to translate evidence-based DSS guidelines and service recommendations into a culturally- and linguistically-meaningful decision aid to help reduce racial, ethnic, and socioeconomic disparities in the early identification of children with DD and their use of pediatric therapy services. To achieve this objective, the study team will conduct in-depth interviews with key community stakeholders to assess their beliefs regarding the help-seeking pathway for children with DD, and the use of DSS guidelines and service recommendations to inform this pathway (Aim 1).

Through the process of Boot Camp Translation, the team will identify factors that promote or impede the integration of standard DSS guidelines and service recommendations with community beliefs regarding the help-seeking pathway for children with DD (Aim 2), and develop a novel DSS decision aid that integrates evidence-based guidelines and service recommendations with community beliefs regarding this help-seeking pathway (Aim 3). The long-term goal of this research is to employ community-based participatory research methods as a means of developing innovative models of care that promote shared decision-making between parents and clinicians, and that advance health equity for underserved populations of children with DD. This goal closely aligns with the mission of the University of Colorado Anschutz Medical Campus and the Department of Physical Medicine and Rehabilitation in improving the health and well-being of children with DD in Colorado, enhancing clients’ experiences and shared decision-making capabilities, and increasing children’s access to services. This project builds upon Dr. Magnusson’s previous work exploring racial, ethnic, and socioeconomic disparities in the identification of children with DD, and in unmet need for pediatric therapy services. Findings from this study will be used as leverage in a Mentored Research Scientist Career Development (K01) Award through the Agency for Healthcare Research and Quality assessing the usability, feasibility, and potential impact of the decision aid on primary and secondary child health outcomes.

Principal Investigator:  Meredith Mealer, RN, 

Title: The feasibility and acceptability of a written exposure therapy (WET) intervention in critical care rehabilitation nurses.

Abstract: Psychological distress is common in healthcare professionals, particularly in high stress areas such as the intensive care  or progressive care units. This pilot study will assess the feasibility and acceptability of a 5-week  written exposure therapy (WET) resiliency focused intervention for critical care rehabilitation nurses. Developed over 30 years ago, expressive writing or written exposure therapies were founded on the Principal that the suppression of traumatic events inhibits the ability to cope with traumatic experiences. Critical care nurses will be asked to write for 30 minutes about the most significant traumatic event they have experienced while working at the bedside as well as an experience that is still causes them distress. Each week will continue to build off the prior weeks writing session with the ultimate goal of reframing the nurse's trauma narrative and future perspective when working in similar distressing environments. This pilot study will help refine the intervention for feasibility and acceptability, so that a larger study can be conducted to determine the efficacy of the intervention at increasing resilience and decreasing symptoms of psychological distress in critical care rehabilitation nurses.

2016 Awards

Principal Investigator: Scott Laker, MD 

Title: Factors Influencing Parental Return-to-Play Decisions in Post Adolescent Sport-Related Concussions: A Mixed-Methods Exploratory Study

Abstract: This is a mixed-methods exploratory study of factors influencing parental concerns regarding their children’s return to play (RTP) following a sports related-concussion (SRC). The study participants will be the parents of adolescents (age 13-18 years) that present to the Children’s’ Hospital Colorado Concussion Program with a SRC. We will recruit 100 participants (parents of adolescents with SRC) to complete a quantitative survey. Twenty of these individuals will also be asked to participate in a qualitative, telephonic interview. As part of regular clinical care, all patients and parents complete a standardized intake questionnaire that includes injury mechanism and characteristics, a symptom severity scale, data about past medical and surgical history, and additional historical information. Permissions will be obtained to use this data. As part of the proposed study protocol, one parent will complete a quantitative pen and paper survey to ascertain factors associated with their child’s current injury that they expect will influence their decision to allow their child to RTP. This survey will also be used to gather information regarding demographics including socioeconomic status, and baseline concussion knowledge. The same parent will be invited to complete a qualitative, telephonic interview, delivered by our post-doctoral team member, to increase understanding regarding factors associated with the parent’s decision making about their child’s RTP. These quantitative and qualitative data will be analyzed to highlight parental concerns in RTP decisions, and to determine if there are any observations that warrant further study.

2014 Awards

Principal Investigator: Cory Christiansen, PT, PhD 
Title: Movement Strategies and Physical Activity after Dysvascular Amputation

Abstract:  Project Abstract: Over 1 million Americans currently live with lower-limb amputation and the number is expected to more than double by 2050. More than 80% of all lower-limb amputations result from vascular complications due to diseases such as severe diabetes mellitus and/or severe peripheral artery disease, known as dysvascular amputation. Patients with dysvascular amputation have difficulty achieving and sustaining independent ambulation with a prosthesis and have low levels of physical activity. Such poor ambulation and physical activity outcomes are likely linked to the compensatory movement patterns that patients adopt following dysvascular amputation. Therefore, the overall aim of this investigation is to improve our understanding of the compensatory movement patterns adopted by patients with unilateral transtibial amputation to achieve independent ambulation and assess how the movement compensations relate to overall physical activity and disability. To identify compensatory movement strategies after dysvascular amputation, a group of participants with diabetes and unilateral transtibial amputation (EXP group) will be compared to a group of participants with diabetes and no major lower limb amputation (CTL group) using measurements of whole-body and body-segment angular momentum. Whole-body and body-segment angular momentum will be measured using 3-dimensional instrumented motion analysis while participants perform level-ground walking (primary functional task), as well as 90 degree turns and stepping up/down onto stair steps. We expect that the EXP group will have 1) higher variability in movement patterns, 2) higher peak to-peak ranges in whole-body angular momentum and larger segmental momentum contributions to whole-body angular momentum, and 3) higher segmental contributions to whole-body angular momentum from the torso/pelvis and contralateral limb compared to the CTL group. Identifying specific compensatory movement pattern characteristics following unilateral transtibial amputation (dysvascular) will provide a basis for developing targeted rehabilitation assessment tools and intervention strategies. In addition, we will examine the correlations that compensatory movement strategies have with gait speed, overall physical activity, and participant-reported disability.

Principal Investigator: Jeffrey Hebert, PT, PhD 
Title: Associations between persistent symptoms and balance dysfunction in Veterans with chronic mild traumatic brain injury

Abstract: Project Abstract: Mild traumatic brain injury (mTBI) is a growing concern for many military Veterans of wars in Iraq and Afghanistan. Postconcussive symptoms (PCS) including dizziness, fatigue and impaired balance are common manifestations of mTBI. Moreover, these PCS symptoms have been found to persist well beyond the onset of mTBI. What is not well understood at this time is how these PCS-related factors correlate, and if they are influenced by other mTBI-related problems including posttraumatic stress disorder (PTSD) and depression. Additionally, why PCS-related symptoms persist in a portion of Veterans with prior mTBI, but not all, also remains elusive. The primary objective of the study is to investigate the potential associations between dizziness, fatigue, dynamic standing balance and mobility-based balance in Veterans with chronic mTBI. The study will also test the relationship between these factors and mental health conditions including PTSD and depression. The specific aims of the proposed study are to determine: 1) if self-reported levels of dizziness and fatigue are related to dynamic standing balance and mobility-based balance in participants with > 6 months post-mTBI; 2) the relationship between self-reported levels of dizziness and fatigue, and the relationship between dynamic standing balance and mobility-based balance, in participants with > 6 months post-mTBI; and 3) the relationship between self-reported levels of PTSD symptoms and depression with dizziness, fatigue, dynamic standing balance and mobility-based balance in participants with > 6 months post-mTBI. The aims of the proposed study will be accomplished by implementing a cross-sectional observational trial. The study is designed to recruit military Veterans with at least a 6-month history of mTBI, with a goal of enrolling and testing 35 participants. Participants will be asked to complete a battery of questionnaires measuring different perceived levels of PCS symptoms including fatigue, dizziness, posttraumatic stress disorder symptoms, and depression. Additionally, participants will perform tests of balance. Dynamic standing balance during multiple sensory input challenges will be measured using the SMART Balance Master®, a computerized dynamic posturography test/sensory organization test (SOT). Mobility-based balance, walking while performing multiple higher level balance-challenging tasks, will be measured using the Community Balance and Mobility (CB&M) scale, a 13-item test that challenges balance and mobility tasks based on speed, precision, accuracy, multi-tasking and sequencing necessary for function and participation in the community. The ability to define what manifestations of mTBI are most likely to explain the reasons for the persistent balance and symptom-related PCS in certain Veterans with mTBI could lead to more focused treatment decisions and research aims. The results of this study will provide data for larger grant submissions to test: 1) how levels of PTSD and depression influence the relationships between dizziness, fatigue and balance; 2) the effectiveness of an exercise-based treatment aimed at improving balance and related PCS symptoms of dizziness and fatigue for Veterans with chronic mTBI.