Symptom Exacerbation and Adverse Events during a Randomized Trial of Early-stage Concussion Rehabilitation.

CONTEXT: Few studies utilize randomized clinical trials (RCT) to quantify clinical intervention safety of rehabilitation after sport-related concussion across sport levels. OBJECTIVE: Describe symptom exacerbation and adverse events (AEs) associated with two concussion rehabilitation interventions. DESIGN: Cluster Randomized Controlled Trial (XXX). SETTING: Sports medicine clinic and field settings. PARTICIPANTS: The RCT enrolled 251 concussed athletes (median age=20 years; female n=48) across 28 sites from New Zealand professional rugby (n=31), Canadian professional football (n=52), United States (U.S.)/Canadian colleges (n=128) and U.S. high schools (n=40). INTERVENTIONS: Two medically supervised interventions: 1) Enhanced Graded Exertion (EGE): international return to sport strategy and sport specific activities only (EGE-only n=119) and 2) Multidimensional Rehabilitation (MDR) followed by EGE: early symptom-directed exercises once symptoms were stable, followed by EGE after symptoms resolved (MDR+EGE n=132). MAIN OUTCOME MEASURES: Primary outcomes were intrasession total symptom severity score exacerbation and significant intersession (increase 10+ severity points) sustained total symptom severity exacerbation, each measured with a Postconcussion Symptom Scale (132 total severity points on scale). Reported AEs were also described. Activity-based rehabilitation sessions (n=1437) were the primary analysis unit. Frequencies, proportions, medians, and Interquartile Ranges (IQRs) were calculated for outcomes by treatment group. RESULTS: The 251 post-injury participants completed 1437 (MDR+EGE=819, EGE-only=618) activity-based intervention sessions. A total of 110 and 105 participants contributed data (those missing had no documented session data) to at least 1 activity-based session in the MDR+EGE and EGE-only arms respectively. Intrasession symptom exacerbations were equivilantly low in MDR+EGE and EGE-only arms (MDR+EGE: 16.7%, 95% CI:14.1%,19.1%; EGE-only: 15.7%, 95% CI: 12.8%,18.6%). In total, 9/819 MDR+EGE sessions (0.9%) and 1/618 EGE-only sessions (0.2%) resulted in a pre- to post-session symptom exacerbation beyond a 10+ severity point increase; 8/9 resolved to <10 points by the next session. Two study-related AEs (1 in each arm) were reported. CONCLUSIONS: Participants in MDR+EGE and EGE-only activities reported equivalently low rates of symptom exacerbation.

Validity and Responsiveness of the Portable Warrior Test of Tactical Agility After Rehabilitation in Service Members With Mild Traumatic Brain Injury.

OBJECTIVE: The Portable Warrior Test of Tactical Agility (POWAR-TOTAL) is a performance-based test designed to assess active-duty service members diagnosed with mild traumatic brain injuries (mTBIs) and could potentially inform return to duty decisions. To examine the validity and responsiveness of the POWAR-TOTAL measure, this study collected self-reported and performance measures by active-duty service members before and after an episode of physical therapist care. METHODS: Seventy-four individuals, enrolled in care for mTBI symptoms at 1 of 2 concussion specialty Intrepid Spirit Centers, were examined the week that they initiated physical therapy with the intention to return to active duty. Self-reported measures of concussion symptoms, pain, posttraumatic stress, headache, dizziness, and sleep quality were used, as were concurrent measures of mobility and balance. The POWAR-TOTAL task (motor and cognitive skills in single and dual-task conditions) was administered. Forty-nine active-duty service members returned for posttherapy testing using the same test battery. Effect sizes for change in measures were calculated. Construct validity was assessed by correlating change scores on POWAR with concurrent self-report and mobility measures. Responsiveness was evaluated using an anchor-based approach. RESULTS: Significant improvements in self-reported and performance-based measures, including POWAR, were observed after therapy with moderate to large effect sizes. Improvement in POWAR performance correlated with improvement in both performance and self-reported measures. After therapy, individuals who registered improvement on the Patient Global Impression of Change scale demonstrated significantly faster POWAR motor performance than those who rated little or no improvement in their condition. CONCLUSION: The POWAR-TOTAL captured improvement on a military-specific task after completing physical therapy for mTBI and could serve as an indicator of physical recovery and readiness for return to duty. IMPACT: Challenging cognitive and motor measures for service members may aid in the assessment of recovery and the ability to successfully return to duty after concussion as part of a comprehensive examination approach.

The American Congress of Rehabilitation Medicine Diagnostic Criteria for Mild Traumatic Brain Injury.

OBJECTIVE: To develop new diagnostic criteria for mild traumatic brain injury (TBI) that are appropriate for use across the lifespan and in sports, civilian trauma, and military settings. DESIGN: Rapid evidence reviews on 12 clinical questions and Delphi method for expert consensus. PARTICIPANTS: The Mild Traumatic Brain Injury Task Force of the American Congress of Rehabilitation Medicine Brain Injury Special Interest Group convened a Working Group of 17 members and an external interdisciplinary expert panel of 32 clinician-scientists. Public stakeholder feedback was analyzed from 68 individuals and 23 organizations. RESULTS: The first 2 Delphi votes asked the expert panel to rate their agreement with both the diagnostic criteria for mild TBI and the supporting evidence statements. In the first round, 10 of 12 evidence statements reached consensus agreement. Revised evidence statements underwent a second round of expert panel voting, where consensus was achieved for all. For the diagnostic criteria, the final agreement rate, after the third vote, was 90.7%. Public stakeholder feedback was incorporated into the diagnostic criteria revision prior to the third expert panel vote. A terminology question was added to the third round of Delphi voting, where 30 of 32 (93.8%) expert panel members agreed that 'the diagnostic label 'concussion' may be used interchangeably with 'mild TBI' when neuroimaging is normal or not clinically indicated.' CONCLUSIONS: New diagnostic criteria for mild TBI were developed through an evidence review and expert consensus process. Having unified diagnostic criteria for mild TBI can improve the quality and consistency of mild TBI research and clinical care.

The Portable Warrior Test of Tactical Agility: A Novel Functional Assessment That Discriminates Service Members Diagnosed With Concussion From Controls.

INTRODUCTION: Return-to-duty (RTD) readiness assessment for service members (SM) following concussion requires complex clinical considerations. The Portable Warrior Test of Tactical Agility (POWAR-TOTAL) is a functional assessment which improves on previous laboratory-based RTD assessments. METHODS: Sixty-four SM diagnosed with concussion and 60 healthy control (HC) SM participated in this study. Group differences were analyzed to validate the POWAR-TOTAL. The High-level Mobility Assessment Test (HiMAT) was used to examine concurrent construct validity. An exploratory logistic regression analysis examined predictive validity. RESULTS: The groups were demographically well-matched except for educational level. POWAR-TOTAL measures were statistically significantly different between the groups with moderate to large effect sizes. Concussed participants were less likely to be able to complete all trials of the POWAR-TOTAL. Motor scores correlated highly with HiMAT scores. POWAR-TOTAL motor task performance and membership in the control group was significantly associated with self-reported physical readiness to deploy. CONCLUSION: The POWAR-TOTAL is a clinically feasible, military relevant assessment that is sensitive to differences between concussed and HC SM. This analysis supports the discriminant and construct validity of the POWAR-TOTAL, and may be useful for medical providers evaluating RTD readiness for SM who have sustained a concussion.

Wearable Sensors Detect Movement Differences in the Portable Warrior Test of Tactical Agility After mTBI in Service Members.

INTRODUCTION: Assessment of functional recovery of service members following a concussion is central to their return to duty. Practical military-relevant performance-based tests are needed for identifying those who might need specialized rehabilitation, for evaluating the progress of recovery, and for making return-to-duty determinations. One such recently developed test is the 'Portable Warrior Test of Tactical Agility' (POWAR-TOTAL) assessment designed for use following concussion in an active duty population. This agility task involves maneuvers used in military training, such as rapid stand-to-prone and prone-to-stand transitions, combat rolls, and forward and backward running. The effect of concussion on the performance of such maneuvers has not been established. MATERIALS AND METHODS: The Institutional Review Board-approved study was conducted at Ft. Bragg, North Carolina, on 57 healthy control (HC) service members (SMs) and 42 well-matched SMs who were diagnosed with concussion and were referred for physical therapy with the intent to return to duty. Each study participant performed five consecutive trials of the POWAR-TOTAL task at full exertion while wearing inertial sensors, which were used to identify the constituent task maneuvers, or phases, and measure their durations. Statistical analyses were performed on durations of three main phases: (1) rising from prone and running, (2) lowering from vertical to prone, and (3) combat rolls. RESULTS: None of the three phases showed significant correlation with age (range 18-45 years) in either group. Gradual improvement in all three phase durations across five trials was observed in the HC group, but not in the concussed group. On average, control subjects performed significantly faster (P < .004 or less) than concussed subjects in all trials in the lowering and rolling phases, but less so in the rising/running phase. Membership in the concussed group had a strong effect on the lowering phase (Cohen's d = 1.05), medium effect on the rolling phase (d = 0.72), and small effect on the rising/running phase (d = 0.49). Individuals in the HC group who had a history of prior concussions were intermediate between the concussed group and the never-concussed group in the lowering and rolling phases. Duration of transitional movements (lowering from standing to prone and combat rolls) was better at differentiating individuals' performance by group (receiver operating characteristic area under the curve [AUC] = 0.83) than the duration of the entire POWAR-TOTAL task (AUC = 0.71). CONCLUSIONS: Inertial sensor analysis reveals that rapid transitional movements (such as lowering from vertical to prone position and combat rolls) are particularly discriminative between SMs recovering from concussion and their concussion-free peers. This analysis supports the validity of POWAR-TOTAL as a useful tool for therapists who serve military SMs.

A pilot study on exertional tasks with physiological measures designed for the assessment of military concussion.

BACKGROUND: Guidelines for clinicians treating military concussion recommend exertional testing before return-to-duty, yet there is currently no standardized task or inclusion of an objective physiological measure like heart rate variability (HRV). METHODOLOGY & RESULTS: We pilot-tested two clinically feasible exertional tasks that include HRV measures and examined reliability of a commercially available heart rate monitor. Testing healthy participants confirmed that the 6-min step test and 2-min pushup test evoked the targeted physiological response, and the Polar H10 was reliable to the gold-standard electrocardiogram. CONCLUSION: Both tasks are brief assessments that can be implemented into primary care setting including the Polar H10 as an affordable way to access HRV. Additional research utilizing these tasks to evaluate concussion recovery can validate standardized exertional tasks for clinical use.

Physical Therapy Evaluation and Treatment After Concussion/Mild Traumatic Brain Injury.

Over the last decade, numerous concussion evidence-based clinical practice guidelines (CPGs), consensus statements, and clinical guidance documents have been published. These documents have typically focused on the diagnosis of concussion and medical management of individuals post concussion, but provide little specific guidance for physical therapy management of concussion and its associated impairments. Further, many of these guidance documents have targeted specific populations in specific care contexts. The primary purpose of this CPG is to provide a set of evidence-based recommendations for physical therapist management of the wide spectrum of patients who have experienced a concussive event. J Orthop Sports Phys Ther 2020;50(4):CPG1-CPG73. doi:10.2519/jospt.2020.0301.

Beliefs About the Influence of Rest During Concussion Recovery May Predict Activity and Symptom Progression Within an Active Duty Military Population.

OBJECTIVES: To evaluate relationships between beliefs about the impact of rest and the level of activities and symptoms over time among active duty Service members sustaining concussion, and whether these relationships vary by provision of concussion education. DESIGN: Longitudinal study using multilevel modeling to assess the relationship between beliefs about rest within 72 hours of concussion and change in activity and symptom level over time, as well as interaction by concussion education at the initial clinic visit. SETTING: Three military treatment facilities. PARTICIPANTS: Study participants included active duty Service members diagnosed with a concussion (N=111; median age, 24 y). Individuals with previous history of concussion within 12 months of study enrollment were excluded. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Activity questionnaire and the Neurobehavioral Symptom Inventory assessed within 72 hours of concussion; at 1 week; and at 1, 3, and 6 month(s) postinjury. RESULTS: Receipt of concussion education from providers was significantly associated with greater belief that rest influences concussion recovery. Greater belief that rest influences symptom recovery at the acute stage of concussion was associated with a greater increase in activities over time, but only among those who received education from their provider. Additionally, greater belief about the influence of rest was related to a more rapid decrease in symptoms over time. CONCLUSIONS: Concussed Service members who underestimate the influence of rest during acute recovery may be at risk for poorer recovery. Treatment of Service members with postconcussive symptoms should consider patient knowledge and/or beliefs about rest and recovery, which may influence prognosis. Our results support the provider's use of concussion education to correct potential misconceptions that may negatively impact symptom recovery.

"Return to duty" as an outcome metric in military concussion research: Problems, pitfalls, and potential solutions.

OBJECTIVE: "Return to duty" (RTD) is often used as an outcome metric in military concussion research, but is inconsistently defined across studies and presents several key problems to researchers. Using results from the Defense and Veterans Brain Injury Center's (DVBIC) Progressive Return to Activity (PRA) study, we highlight problems with RTD, and suggest solutions to inform future efforts. METHOD: 116 service members (SMs) were enrolled in one of two groups (pre-implementation and post-implementation of the PRA Clinical Recommendation [CR]). Data, including the Neurobehavioral Symptom Inventory (NSI-22), was collected within 72-hours of injury (baseline), and at 1-week, 1-month, 3-months, and 6-months post-injury. Our analyses focused on three time points: baseline, approximate RTD date, and post-RTD follow-up, with RTD data captured via self-report and electronic medical record (EMR). Secondary analyses included comparisons across PRA-CR implementation groups. RESULTS: Of those SMs (<50% of the sample) with both self-reported and EMR RTD dates, dates largely did not match (range 1 to 36 days). RTD (either date) also did not indicate symptom recovery, with >50% of SMs reporting "abnormally high" symptom levels (i.e., NSI-22 total ≥75th percentile) at RTD, and over 50% of SMs reporting at least one significant symptom (i.e., any NSI-22 item ≥ 2) after RTD. CONCLUSIONS: Our data demonstrate challenges encountered with a RTD outcome metric. Military concussion researchers should strive to use a well-defined RTD outcome metric. We propose defining RTD as a return to deployment readiness. Further, researchers should utilize Department of Defense definitions of Individual Medical Readiness and Deployment Limiting conditions to increase specificity of a RTD outcome metric. Improving the way RTD is captured will improve confidence that tools used after a SM sustains concussion are adequately informing RTD decisions.

Activity Level During Acute Concussion May Predict Symptom Recovery Within an Active Duty Military Population.

OBJECTIVE: To evaluate the impact on symptom resolution of activity acutely following a concussion and the role of acute-phase symptoms on this relationship among active duty service members (SMs). SETTING: Three military installations. PARTICIPANTS: Sixty-two SMs aged 18 to 44 years who sustained a concussion within 72 hours of enrollment. DESIGN: Longitudinal design with data collected within 72 hours of injury (baseline, n = 62) and at 1 week (n = 57), 1 month (n = 50), 3 months (n = 41), and 6 months (n = 40) postinjury. MAIN MEASURES: Baseline activity level using a 60-item Activity Questionnaire. Symptom level at baseline and during follow-up using Neurobehavioral Symptoms Inventory. RESULTS: Significant interaction (Pi < .05) was found, with significant main effects (P < .05) limited to SMs with elevated baseline symptomatology. Among these participants, greater baseline total activity was significantly related to greater vestibular symptoms at 1, 3, and 6 months (ß = .61, .63, and .59, respectively). Significant associations were also found for particular types of baseline activity (eg, physical; vestibular/balance; military-specific) and symptoms at 1, 3, and/or 6 months postinjury. CONCLUSION: These results provide support for clinical guidance that symptomatic SMs, particularly those with high levels of acute symptoms, may need to avoid excessive activity acutely following concussion.

Management of Concussion and Mild Traumatic Brain Injury: A Synthesis of Practice Guidelines.

At least 3 million Americans sustain a mild traumatic brain injury (mTBI) each year, and 1 in 5 have symptoms that persist beyond 1 month. Standards of mTBI care have evolved rapidly, with numerous expert consensus statements and clinical practice guidelines published in the last 5 years. This Special Communication synthesizes recent expert consensus statements and evidenced-based clinical practice guidelines for civilians, athletes, military, and pediatric populations for clinicians practicing outside of specialty mTBI clinics, including primary care providers. The article offers guidance on key clinical decisions in mTBI care and highlights priority interventions that can be initiated in primary care to prevent chronicity.

Targeting the Autonomic Nervous System Balance in Patients with Chronic Low Back Pain Using Transcranial Alternating Current Stimulation: A Randomized, Crossover, Double-Blind, Placebo-Controlled Pilot Study.

BACKGROUND: Chronic low back pain (CLBP) is characterized by an alteration in pain processing by the central nervous system that may affect autonomic nervous system (ANS) balance. Heart rate variability (HRV) reflects the balance of parasympathetic and sympathetic ANS activation. In particular, respiratory sinus arrhythmia (RSA) solely reflects parasympathetic input and is reduced in CLBP patients. Yet, it remains unknown if non-invasive brain stimulation can alter ANS balance in CLBP patients. OBJECTIVE: To evaluate if non-invasive brain stimulation modulates the ANS, we analyzed HRV metrics collected in a previously published study of transcranial alternating current stimulation (tACS) for the modulation of CLBP through enhancing alpha oscillations. We hypothesized that tACS would increase RSA. METHODS: A randomized, crossover, double-blind, sham-controlled pilot study was conducted to investigate the effects of 10Hz-tACS on metrics of ANS balance calculated from electrocardiogram (ECG). ECG data were collected for 2 mins before and after 40 mins of 10Hz-tACS or sham stimulation. RESULTS: There were no significant changes in RSA or other frequency-domain HRV components from 10Hz-tACS. However, exploratory time-domain HRV analyses revealed a significant increase in the standard deviation of normal intervals between R-peaks (SDNN), a measure of ANS balance, for 10Hz-tACS relative to sham. CONCLUSION: Although tACS did not significantly increase RSA, we found in an exploratory analysis that tACS modulated an integrated HRV measure of both ANS branches. These findings support the further study of how the ANS and alpha oscillations interact and are modulated by tACS. CLINICALTRIALSGOV: Transcranial Alternating Current Stimulation in Back Pain - Pilot Study, NCT03243084.

How Do We Meet the Challenges of Assessing and Managing Concussion?

Despite advances in the assessment, diagnosis, prognosis, and management of the patient with mild traumatic brain injury (mTBI) or concussion, the condition continues to frustrate clinicians and researchers. The November 2019 special issue of the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) supports and represents an interdisciplinary approach to assessment, management, and treatment of mTBI/concussion. The articles further highlight the evolving role of the physical therapist throughout the clinical course post concussion. It is with gratitude to the authors who contributed to this special issue of JOSPT that we present the evidence and practices currently available to clinicians in the assessment and treatment of mTBI/concussion. J Orthop Sports Phys Ther 2019;49(11):766-767. doi:10.2519/jospt.2019.0107.

Use of the Progressive Return to Activity Guidelines May Expedite Symptom Resolution After Concussion for Active Duty Military.

BACKGROUND: Clinical recommendations for concussion management encourage reduced cognitive and physical activities immediately after injury, with graded increases in activity as symptoms resolve. Empirical support for the effectiveness of such recommendations is needed. PURPOSE: To examine whether training medical providers on the Defense and Veterans Brain Injury Center's Progressive Return to Activity Clinical Recommendation (PRA-CR) for acute concussion improves patient outcomes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: This study was conducted from 2016 to 2018 and compared patient outcomes before and after medical providers received an educational intervention (ie, provider training). Patients, recruited either before or after intervention, were assessed at ≤72 hours, 1 week, 1 month, 3 months, and 6 months after a concussion. The participant population included 38 military medical providers and 106 military servicemembers with a diagnosed concussion and treated by one of the military medical providers: 58 patient participants received care before the intervention (ie, provider training) and 48 received care after intervention. The primary outcome measure was the Neurobehavioral Symptom Inventory. RESULTS: The patients seen before and after the intervention were predominantly male (89.7% and 93.8%, respectively) of military age (mean ± SD, 26.62 ± 6.29 years and 25.08 ± 6.85 years, respectively) and a mean ± SD of 1.92 ± 0.88 days from injury. Compared with patients receiving care before intervention, patients receiving care after intervention had smaller increases in physical activities (difference in mean change; 95% CI, 0.39 to 6.79) and vestibular/balance activities (95% CI, 0.79 to 7.5) during the first week of recovery. Although groups did not differ in symptoms at ≤72 hours of injury (d = 0.22; 95% CI, -2.21 to 8.07), the postintervention group reported fewer symptoms at 1 week (d = 0.61; 95% CI, 0.52 to 10.92). Postintervention patients who completed the 6-month study had improved recovery both at 1 month (d = 1.55; 95% CI, 5.33 to 15.39) and 3 months after injury (d = 1.10; 95% CI, 2.36 to 11.55), but not at 6 months (d = 0.35; 95% CI, 5.34 to 7.59). CONCLUSION: Training medical providers on the PRA-CR for management of concussion resulted in expedited recovery of patients.

Methodology and Implementation of a Randomized Controlled Trial (RCT) for Early Post-concussion Rehabilitation: The Active Rehab Study.

Background: Sports-related concussion (SRC) is a complex injury with heterogeneous presentation and management. There are few studies that provide guidance on the most effective and feasible strategies for recovery and return to sports participation. Furthermore, there have been no randomized studies of the feasibility, safety, and efficacy of early rehabilitation strategies across multiple sports and age groups. This international cluster-randomized pragmatic trial evaluates the effectiveness of early multi-dimensional rehabilitation integrated with the current return to sport strategy vs. the current return to sport strategy alone. Methods: The study is a cluster-randomized pragmatic trial enrolling male and female athletes from 28 sites. The sites span three countries, and include multiple sports, levels of play (high school, college, and professional), and levels of contact. The two study arms are Enhanced Graded Exertion (EGE) and Multidimensional Rehabilitation (MDR). The EGE arm follows the current return to sport strategy and the MDR arm integrates early, MDR strategies in the context of the current return to sport strategy. Each arm employs a post-injury protocol that applies to all athletes from that site in the event they sustain a concussion during their study enrollment. Participants are enrolled at pre-season baseline. Assessment timepoints include pre-season baseline, time of injury (concussion), 24-48 h post-injury, asymptomatic, and 1-month post-injury. Symptoms and activity levels are tracked post injury through the return to play process and beyond. Injury and recovery characteristics are obtained for all participants. Primary endpoints include time to medical clearance for full return to sport and time to become asymptomatic. Secondary endpoints include symptom, neurocognitive, mental status, balance, convergence insufficiency, psychological distress, and quality of life trajectories post-injury. Discussion: Outputs from the trial are expected to inform both research and clinical practice in post-concussion rehabilitation across all levels of sport and extend beyond civilian medicine to care for military personnel. Ethics and Dissemination: The study is approved by the data coordinating center Institutional Review Board and registered at clinicaltrials.gov. Dissemination will include peer-reviewed publications, presentation to patients and public groups, as well as dissemination in other healthcare and public venues of interest. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT02988596 Trial Funding: National Football League.

A Treatment-Based Profiling Model for Physical Therapy Management of Patients Following a Concussive Event.

SYNOPSIS: Concussions are a public health concern that affects individuals across the life span. The multifaceted effects of concussion warrant an interdisciplinary management strategy that may include physical therapy. However, physical therapists may feel underprepared for clinical decision making following a concussive event. We propose a new treatment-based profiling model to help physical therapists manage patients following a concussive event. This profiling model, based on symptom type and intensity, disability status, and response to movement, prioritizes treatment emphasis on (1) symptom management, (2) movement system optimization, or (3) performance optimization. We consider contextual factors that modify treatment decision making and present examples of each treatment-based profile. J Orthop Sports Phys Ther 2019;49(11):829-841. doi:10.2519/jospt.2019.8869.

Activity Level and Type During Post-acute Stages of Concussion May Play an Important Role in Improving Symptoms Among an Active Duty Military Population.

Background: Previous research demonstrates that early rest and gradual increases in activity after concussion can improve symptoms; however, little is known about the intensity and type of activity during post-acute time periods-specifically months post-injury-that may promote optimal recovery in an active duty service member (SM) population. Objective: The objectives of this study were to investigate how activity level and type at the post-acute stages of concussion (at 1 and 3 month[s] post-injury) impact subsequent symptoms among SMs, and how this relationship might differ by the level of symptoms at the time of injury. Methods: Participants included 39 SMs ages 19-44 years from 3 military installations who were enrolled within 72 h after sustaining a concussion. Linear regression was used to evaluate whether the association between activity level at 1 or 3 month(s) post-injury (as measured by a multi-domain Activity Questionnaire) and subsequent symptoms at 3 and/or 6 months (as measured by the Neurobehavioral Symptom Inventory) varied by the level of symptoms at acute stages of concussion. Partial correlation was used to evaluate relationships that did not differ by acute symptom level. Symptoms at the time of activity assessment (1 or 3 month[s]) were accounted for in all models, as well as activity level at acute stages of concussion. Results: Greater physical and vestibular/balance activity at 1 month were significantly correlated with lower symptoms at 3 months, but not at 6 months post-injury. There were no significant associations found between activity (total or by type) at 3 months and symptoms at 6 months. The association between activity level at either 1 or 3 months and subsequent symptoms at 3 and/or 6 months did not differ by the level of acute symptoms. Conclusion: The intensity and type of activities in which SMs engage at post-acute stages of concussion may impact symptom recovery. Although low levels of activity have been previously shown to be beneficial during the acute stage of injury, higher levels of activity may provide benefit at later stages. These findings provide support for the importance of monitoring and managing activity level beyond the acute stage of concussion.

Clinical Utility and Analysis of the Run-Roll-Aim Task: Informing Return-to-Duty Readiness Decisions in Active-Duty Service Members.

INTRODUCTION: The Assessment of Military Multitasking Performance (AMMP1) consists of six dual-task and multitask military-relevant performance-based assessments which were developed to provide assistance in making return-to-duty decisions after concussion or mild traumatic brain injury (mTBI.) The Run-Roll-Aim (RRA) task, one component of the AMMP, was developed to target vulnerabilities following mTBI including attention, visual function, dynamic stability, rapid transition, and vestibular function. One aim of this study was to assess the known-group and construct validity of the RRA, and additionally to further explore reliability limitations reported previously. MATERIALS AND METHODS: A cross-sectional study consisting of 84 Active Duty service members in two groups (healthy control - HC and individuals experiencing persistent mTBI symptoms) completed neurocognitive tests and the RRA. The RRA task requires a high level of mobility and resembles military training activities in a maneuver that includes combat rolls, fast transitions, obstacle avoidance, and visual search. Observational and inertial sensor data were compared between groups and performance across four trial times was compared within groups. Correlations between RRA results and neurocognitive test scores were analyzed. RESULTS: Simple observational measures (time, errors) did not differ between groups. Spectral power analysis of the inertial sensor data showed significant differences in motor performance between groups. Within group one-way ANOVAs showed that in HC trial 1, time was significantly different than trials 2,3 and 4 (F(3,47) = 4.60, p < 0.01, Tukey HSD p < 0.05) while the mTBI group showed no significant difference in time between trials. During testing individuals with mTBI were less likely to complete the multiple test trials or required additional rest between trials than HCs (χ2 = 10.78, p < 0.01). Small but significant correlations were seen with two neurocognitive tests of attention and RRA performance time. CONCLUSION: While observational scores were not sensitive to group differences, inertial sensor data showed motor performance on the forward run, combat roll, and backward run differed significantly between groups. The RRA task appeared challenging and provoked symptoms in the mTBI group, causing 8 of 33 mTBI participants to stop the task or require additional rest between trials while none of the HC participants had to stop. Individuals with mTBI demonstrated slower learning of the complex motor sequence compared to HCs who had significant improvement after one trial of RRA. Complex novel training maneuvers like RRA may aid clinicians in informing return to duty decisions.