Detecting gait abnormalities after concussion or mild traumatic brain injury: A systematic review of single-task, dual-task, and complex gait

An integrated approach to the assessment of balance and functional mobility in individuals with history of severe traumatic brain injury

Individuals who experienced severe Traumatic Brain Injury (sTBI) are often characterized by relevant motor dysfunctions which are likely to negatively affect activities of daily living and quality of life and often persist for years. However, detailed objective information about their magnitude are scarce. The aim of this study was to quantitatively assess the extent of motor deficits in terms of postural control effectiveness under static and dynamic conditions and to investigate the existence of possible correlations between the results of clinical tests and instrumental measures. Postural sway and functional mobility (i.e., instrumented Timed Up and Go test, iTUG) were objectively measured in 18 individuals with sTBI and 18 healthy controls using a pressure plate and a wearable inertial sensor. Additionally, participants with history of sTBI completed the Rivermead Mobility Index (RMI). One-way ANOVA and Spearman's rank correlation analysis were employed to examine differences between the two groups and determine potential correlations between the instrumental tests and clinical scales. The results show that people with sTBI were characterized by larger sway area and longer iTUG walking sub-phase. Significant correlations were also detected between RMI scores and iTUG total duration, as well as the walking phase. Taken together, these findings suggest that, even years after the initial injury, individuals with sTBI appear characterized by impaired postural control and functional mobility, which appears correlated with the RMI score. The integration of instrumental measures with clinical scales in the routine assessment and treatment of individuals with sTBI would result in more comprehensive, objective, and sensitive evaluations, thus improving precision in treatment planning, enabling ongoing progress monitoring, and highlighting the presence of motor deficits even years after the initial injury. Such integration is of importance for enhancing the long-term quality of life for individuals with sTBI.

Relation Between Cognitive Assessment and Clinical Physical Performance Measures After Mild Traumatic Brain Injury

OBJECTIVES

To investigate the relation between cognitive and motor performance in individuals with mild traumatic brain injury (mTBI) and examine differences in both cognitive and motor performance between adults after mTBI and healthy controls.

DESIGN

Multi-center, cross-sectional study.

SETTING

Three institutional sites (Courage Kenny Research Center, Minneapolis, MN, Oregon Health & Science University, Portland, OR, and University of Utah, Salt Lake City, UT).

PARTICIPANTS

Data were collected from 110 participants (N=110), including those with mTBI and healthy controls, who completed cognitive and physical performance assessments.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Cognitive assessments involved the Automated Neuropsychological Assessment Metrics to evaluate domains of attention, memory, reaction time, processing speed, and executive function. Physical performance was evaluated through clinical performance assessments, such as the 1-min walk test, the modified Illinois Agility Test, the Functional Gait Assessment Tool, the High-Level Mobility Assessment Tool, a complex turning course, and a 4-Item Hybrid Assessment of Mobility for mTBI. Participants also completed additional trials of the 1-min walk test, modified Illinois Agility Test, and complex turning course with a simultaneous cognitive task.

RESULTS

Individuals with mTBI performed worse on cognitive assessments, as well as several of the physical performance assessments compared with healthy controls. Complex tasks were more strongly related to cognitive assessments compared with simple walking tasks.

CONCLUSIONS

Combining complex motor tasks with cognitive demands may better demonstrate functional performance in individuals recovering from mTBI. By understanding the relation between cognitive and physical performance in individuals recovering from mTBI, clinicians may be able to improve clinical care and assist in return to activity decision-making.

Prefrontal Cortex Activity During Gait in People With Persistent Symptoms After Concussion

BACKGROUND

Concussions result in transient symptoms stemming from a cortical metabolic energy crisis. Though this metabolic energy crisis typically resolves in a month, symptoms can persist for years. The symptomatic period is associated with gait dysfunction, the cortical underpinnings of which are poorly understood. Quantifying prefrontal cortex (PFC) activity during gait may provide insight into post-concussion gait dysfunction. The purpose of this study was to explore the effects of persisting concussion symptoms on PFC activity during gait. We hypothesized that adults with persisting concussion symptoms would have greater PFC activity during gait than controls. Within the concussed group, we hypothesized that worse symptoms would relate to increased PFC activity during gait, and that increased PFC activity would relate to worse gait characteristics.

METHODS

The Neurobehavior Symptom Inventory (NSI) characterized concussion symptoms. Functional near-infrared spectroscopy quantified PFC activity (relative concentration changes of oxygenated hemoglobin [HbO2]) in 14 people with a concussion and 25 controls. Gait was assessed using six inertial sensors in the concussion group.

RESULTS

Average NSI total score was 26.4 (13.2). HbO2 was significantly higher (P = .007) for the concussed group (0.058 [0.108]) compared to the control group (-0.016 [0.057]). Within the concussion group, HbO2 correlated with NSI total symptom score (ρ = .62; P = .02), sagittal range of motion (r = .79; P = .001), and stride time variability (r = -.54; P = .046).

CONCLUSION

These data suggest PFC activity relates to symptom severity and some gait characteristics in people with persistent concussion symptoms. Identifying the neurophysiological underpinnings to gait deficits post-concussion expands our knowledge of motor behavior deficits in people with persistent concussion symptoms.

Associations Between Head Injury and Subsequent Risk of Falls: Results From the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND OBJECTIVES

Falls are a leading cause of head injury among older adults, but the risk of fall occurring after a head injury is less well-characterized. We sought to examine the association between head injury and subsequent risk of falls requiring hospital care among community-dwelling older adults.

METHODS

This analysis included 13,081 participants in the Atherosclerosis Risk in Communities Study enrolled in 1987-1989 and followed through 2019. The association of head injury (time-varying exposure, self-reported and/or ICD-9/10 code identified) with the risk of subsequent (occurring >1-month after head injury) falls requiring hospital care (ICD-9/10 code defined) was modeled using Cox proportional hazards regression. Secondary analyses included Fine and Gray proportional hazards regression to account for the competing risk of death, analysis of head injury frequency and severity, and formal testing for interaction by age, sex, and race. Models were adjusted for age, sex, race/center, education, military service, alcohol consumption, smoking, diabetes, hypertension, and psychotropic medication use.

RESULTS

The mean age of participants at baseline was 54 years, 58% were female, 28% were Black, and 14% had at least one head injury occurring over the study period. Over a median 23 years of follow-up, 29% of participants had a fall requiring medical care. In adjusted Cox proportional hazards models, individuals with head injury had 2.01 (95% CI 1.85-2.18) times the risk of falls compared with individuals without head injury. Accounting for the competing risk of mortality, individuals with head injury had 1.69 (95% CI 1.57-1.82) times the risk of falls compared with individuals without head injury. We observed stronger associations among men compared with women (men: hazard ratio [HR] = 2.60, 95% CI 2.25-3.00; women: HR = 1.80, 95% CI 1.63-1.99, p-interaction <0.001). We observed evidence of a dose-response association for head injury number and severity with fall risk (1 injury: HR = 1.68, 95% CI 1.53-1.84; 2+ injuries: HR = 2.37, 95% CI 1.92-2.94 and mild: HR = 1.97, 95% CI 1.78-2.18; moderate/severe/penetrating: HR = 2.50, 95% CI 2.06-3.02).

DISCUSSION

Among community-dwelling older adults followed over 30 years, head injury was associated with subsequent falls requiring medical care. We observed stronger associations among men and with increasing number and severity of head injuries. Whether older individuals with head injury might benefit from fall prevention measures should be a focus of future research.

The Microsoft HoloLens 2 Provides Accurate Biomechanical Measures of Performance During Military-Relevant Activities in Healthy Adults

INTRODUCTION

Augmented reality systems, like the HoloLens 2 (HL2), have the potential to provide accurate assessments of mild traumatic brain injury (mTBI) symptoms in military personnel by simulating complex military scenarios while objectively measuring the user's movements with embedded motion sensors. The aim of this project was to determine if biomechanical measures of marching and squatting, derived from the HL2 motion sensors, were statistically equivalent, within 5%, to metrics derived from the gold-standard three-dimensional motion capture (MoCap) system.

MATERIALS AND METHODS

Sixty-four adults (18-45 years; 34 males) completed a squatting and a marching task under single- (motor) and dual-task (motor + cognitive) conditions. Positional data from the HL2 and MoCap were simultaneously collected during the tasks and used to calculate and compare biomechanical outcomes. The HL2's augmented reality capabilities were utilized to deliver the cognitive component of the marching dual task.

RESULTS

Equivalence testing indicated the HL2 and MoCap measures were within 5% in all squatting metrics-trial time, squat duration, squat velocity, squat depth, and dwell time. Marching metrics, including trial time, step count, stepping rate, and step interval, were also equivalent between the two systems. The mean reaction time for responses during the Stroop test was 810 (125) milliseconds per response.

CONCLUSIONS

Biomechanical outcomes characterizing performance during two common military movements, squatting and marching, were equivalent between the HL2 and MoCap systems in healthy adults. Squatting and marching are two military-relevant tasks that require strength, motor coordination, and balance to perform, all of which are known to be affected by mTBI. Taken together, the data provide support for using the HL2 platform to deliver military-specific assessment scenarios and accurately measure performance during these activities. Utilizing objective and quantitative measures of motor function may enhance the management of military mTBI and reduce unnecessary risk to service members.

Development of the Troop Readiness Evaluation With Augmented Reality Return-to-Duty (Troop READY) Platform to Aid in the Detection and Treatment of Military Mild Traumatic Brain Injury

INTRODUCTION

Mild traumatic brain injury (mTBI) is prevalent in service members (SMs); however, there is a lack of consensus on the appropriate approach to return to duty (RTD). Head-mounted augmented reality technology, such as the HoloLens 2, can create immersive, salient environments to more effectively evaluate relevant military task performance. The Troop Readiness Evaluation with Augmented Reality Return-to-Duty (READY) platform was developed to objectively quantify cognitive and motor performance during military-specific activities to create a comprehensive approach to aid in mTBI detection and facilitate appropriate RTD. The aim of this project was to detail the technical development of the Troop READY platform, the outcomes, and its potential role in the aiding detection and RTD decision-making post mTBI. The secondary aim included evaluating the safety, feasibility, and SM usability of the Troop READY platform.

MATERIALS AND METHODS

The Troop READY platform comprises three assessment modules of progressing complexity: (1) Static and Dynamic Mobility, (2) Rifle Qualification Test, and (3) Small Unit Operations Capacity-Room Breach/Clearing Exercise. The modules were completed by 137 active duty SMs. Safety was assessed through monitoring of adverse events. Feasibility was assessed using the self-directed module completion rate. Usability was measured using the Systems Usability Scale.

RESULTS

No adverse events occurred. Completion rates of the three modules ranged from 98 to 100%. In terms of usability, the mean Systems Usability Scale score of all participants was 83.92 (13.95), placing the Troop READY platform in the good-to-excellent category. Objective motor and cognitive outcomes were generated for each module.

CONCLUSION

The Troop READY platform delivers self-directed, salient assessment modules to quantify single-task, dual-task, and unit-based performance in SMs. The resultant data provide insight into SM performance through objective outcomes and identify specific areas of executive or motor function that may be slow to recover following mTBI.

Associations Between Cognitive Function and ACL Injury-Related Biomechanics: A Systematic Review

CONTEXT

Does lower baseline cognitive function predispose athletes to ACL injury risk, especially when performing unplanned or dual-task movements?

OBJECTIVE

To evaluate the association between cognitive function and biomechanics related to ACL injuries during cognitively challenging sports movements.

DATA SOURCES

PubMed (MEDLINE), Web of Science, Scopus, and SciELO databases were searched; additional hand searching was also conducted.

STUDY SELECTION

The following inclusion criteria had to be met: participants completed (1) a neurocognitive test, (2) a cognitively challenging sport-related task involving lower limbs, and (3) a biomechanical analysis. The following criteria determined exclusion from the review: studies involving participants with (1) recent or current musculoskeletal injuries; (2) recent or current concussion; (3) ACL surgical reconstruction, reviews of the literature, commentary or opinion articles, and case studies.

STUDY DESIGN

Systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) statement and registered at the International Prospective Register of Systematic Reviews (PROSPERO).

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

Two of authors independently extracted data and assessed the methodological quality of the articles with the Downs and Black and ROBINS-I checklists, to assess methodological quality and risk of bias, respectively.

RESULTS

Six studies with different methodologies and confounding factors were included in this review. Of these 6 studies, 3 were ranked as high-quality, 3 demonstrated a low risk of bias, 2 a moderate risk, and 1 a severe risk. Five studies found a cognitive-motor relationship, with worse cognitive performance associated with increased injury risk, with 1 study reporting the opposite directionality for 1 variable. One study did not identify any interaction between cognitive function and biomechanical outcomes.

CONCLUSION

Worse cognitive performance is associated with an increased injury risk profile during cognitively challenging movements.

Sports-Related Concussion Assessment: A New Physiological, Biomechanical, and Cognitive Methodology Incorporating a Randomized Controlled Trial Study Protocol

BACKGROUND

Taking part in moderate-to-vigorous exercise in contact sports on a regular basis may be linked to an increase in cerebrovascular injury and head trauma. Validated objective measures are lacking in the initial post-event diagnosis of head injury. The exercise style, duration, and intensity may also confound diagnostic indicators. As a result, we propose that the new Interdisciplinary Group in Movement & Performance from Acute & Chronic Head Trauma (IMPACT) analyze a variety of functional (biomechanical and motor control) tests as well as related biochemistry to see how they are affected by contact in sports and head injury. The study's goal will be to look into the performance and physiological changes in rugby players after a game for head trauma and injury.

METHODS

This one-of-a-kind study will use a randomized controlled trial (RCT) utilizing a sport participation group and a non-participation control group. Forty male rugby 7 s players will be recruited for the study and allocated randomly to the experimental groups. The intervention group will participate in three straight rugby matches during a local 7 s rugby event. At the pre-match baseline, demographic and anthropometric data will be collected. This will be followed by the pre-match baseline collection of biochemical, biomechanical, and cognitive-motor task data. After three consecutive matches, the same measures will be taken. During each match, a notational analysis will be undertaken to obtain contact information. All measurements will be taken again 24, 48, and 72 h after the third match.

DISCUSSION

When the number of games increases owing to weariness and/or stressful circumstances, we expect a decline in body movement, coordination, and cognitive-motor tasks. Changes in blood biochemistry are expected to correspond to changes in biomechanics and cognitive-motor processes. This research proposal will generate considerable, ecologically valid data on the occurrence of head trauma events under game conditions, as well as the influence of these events on the biological systems of the performers. This will lead to a greater understanding of how sports participants react to exercise-induced injuries. This study's scope will have far-reaching ramifications for doctors, coaches, managers, scientists, and sports regulatory bodies concerned with the health and well-being of athletic populations at all levels of competition, including all genders and ages.

Mild Traumatic Brain Injury and Functional Outcome in Older Adults: Pain Interference But Not Cognition Mediates the Relationship Between Traumatic Injury and Functional Difficulties

OBJECTIVE

To examine functional status of older people 3 months after mild traumatic brain injury (mTBI) and identify whether pain interference or cognition mediates any relationship found between injury status and functional outcomes.

SETTING

Patients admitted to a Melbourne-based emergency department.

PARTICIPANTS

Older adults 65 years and older: 40 with mTBI, 66 with orthopedic injury without mTBI (TC), and 47 healthy controls (CC) without injury.

DESIGN

Observational cohort study.

MAIN MEASURES

Functional outcome was measured using the World Health Organization Disability Assessment Schedule (WHODAS 2.0) and single- and dual-task conditions of the Timed-Up-and-Go task. Pain interference and cognitive performance at 3 months post-injury were examined as mediators of the relationship between injury status (injured vs noninjured) and functional outcome.

RESULTS

Patients with mTBI and/or orthopedic injury reported greater difficulties in overall functioning, including community participation, compared with noninjured older people (CC group). Both trauma groups walked slower than the CC group on the mobility task, but all groups were similar on the dual-task condition. Pain interference mediated the relationship between injury status and overall functioning [ b = 0.284; 95% CI = 0.057, 0.536), community participation ( b = 0.259; 95% CI = 0.051, 0.485), and mobility ( b = 0.116; 95% CI = 0.019, 0.247). However, cognition did not mediate the relationship between injury status and functional outcomes.

CONCLUSIONS

Three months after mild traumatic injury (with and without mTBI), patients 65 years and older had greater functional difficulties compared with noninjured peers. Pain interference, but not cognition, partially explained the impact of traumatic injury on functional outcomes. This highlights the importance of reducing pain interference for older patients after injury (including mTBI) to support better functional recovery.

Effects of contact/collision sport history on gait in early- to mid-adulthood

BACKGROUND

To determine the effect of contact/collision sport participation on measures of single-task (ST) and dual-task (DT) gait among early- to middle-aged adults.

METHODS

The study recruited 113 adults (34.88 ± 11.80 years, (mean ± SD); 53.0% female) representing 4 groups. Groups included (a) former non-contact/collision athletes and non-athletes who are not physically active (n = 28); (b) former non-contact/collision athletes who are physically active (n = 29); (c) former contact/collision sport athletes who participated in high-risk sports and are physically active (n = 29); and (d) former rugby players with prolonged repetitive head impact exposure history who are physically active (n = 27). Gait parameters were collected using inertial measurement units during ST and DT gait. DT cost was calculated for all gait parameters (double support, gait speed, and stride length). Groups were compared first using one-way analysis of covariance. Then a multiple regression was performed for participants in the high-risk sport athletes and repetitive head impact exposure athletes groups only to predict gait outcomes from contact/collision sport career duration.

RESULTS

There were no significant differences between groups on any ST, DT, or DT cost outcomes (p > 0.05). Contact/collision sport duration did not predict any ST, DT, or DT cost gait outcomes.

CONCLUSION

Years and history of contact/collision sport participation does not appear to negatively affect or predict neurobehavioral function in early- to mid-adulthood among physically active individuals.

Volitional Head Movement Deficits and Alterations in Gait Speed Following Mild Traumatic Brain Injury

OBJECTIVE

Unconstrained head motion is necessary to scan for visual cues during navigation, for minimizing threats, and to allow regulation of balance. Following mild traumatic brain injury (mTBI) people may experience alterations in head movement kinematics, which may be pronounced during gait tasks. Gait speed may also be impacted by the need to turn the head while walking in these individuals. The aim of this study was to examine head kinematics during dynamic gait tasks and the interaction between kinematics and gait speed in people with persistent symptoms after mTBI.

SETTING

A clinical assessment laboratory.

DESIGN

A cross-sectional, matched-cohort study.

PARTICIPANTS

Forty-five individuals with a history of mTBI and 46 age-matched control individuals.

MAIN MEASURES

All participants were tested at a single time point and completed the Functional Gait Assessment (FGA) while wearing a suite of body-mounted inertial measurement units (IMUs). Data collected from the IMUs were gait speed, and peak head rotation speed and amplitude in the yaw and pitch planes during the FGA-1, -3, and -4 tasks.

RESULTS

Participants with mTBI demonstrated significantly slower head rotations in the yaw ( P = .0008) and pitch ( P = .002) planes. They also demonstrated significantly reduced amplitude of yaw plane head rotations ( P < .0001), but not pitch plane head rotations ( P = .84). Participants with mTBI had significantly slower gait speed during normal gait (FGA-1) ( P < .001) and experienced a significantly greater percent decrease in gait speed than healthy controls when walking with yaw plane head rotations (FGA-3) ( P = .02), but not pitch plane head rotations (FGA-4) ( P = .11).

CONCLUSIONS

Participants with mTBI demonstrated smaller amplitudes and slower speeds of yaw plane head rotations and slower speeds of pitch plane head rotations during gait. Additionally, people with mTBI walked slower during normal gait and demonstrated a greater reduction in gait speed while walking with yaw plane head rotations compared with healthy controls.

A Hybrid Assessment of Clinical Mobility Test Items for Evaluating Individuals With Mild Traumatic Brain Injury

BACKGROUND AND PURPOSE

The Functional Gait Assessment (FGA) and High Level Mobility Assessment Tool (HiMAT) are clinical batteries used to assess people with mild traumatic brain injury (mTBI). However, neither assessment was specifically developed for people with mTBI; the FGA was developed to evaluate vestibular deficits, and the HiMAT was developed for individuals with more severe TBI. To maximize the sensitivity and reduce the time burden of these assessments, the purpose of this study was to determine the combination of FGA and HiMAT items that best discriminates persons with persistent symptoms from mTBI from healthy controls.

METHODS

Fifty-three symptomatic civilians with persistent symptoms from mTBI (21% male, aged 31 (9.5) years, 328 [267] days since concussion) and 57 healthy adults (28% male, aged 32 (9.6) years) participated across 3 sites. The FGA and HiMAT were evaluated sequentially as part of a larger study. To determine the best combination of items, a lasso-based generalized linear model (glm) was fit to all data.

RESULTS

The area under the curve (AUC) for FGA and HiMAT total scores was 0.68 and 0.66, respectively. Lasso regression selected 4 items, including FGA Gait with Horizontal Head Turns and with Pivot Turn, and HiMAT Fast Forward and Backward Walk, and yielded an AUC (95% confidence interval) of 0.71 (0.61-0.79) using standard scoring.

DISCUSSION AND CONCLUSIONS

The results provide initial evidence supporting a reduced, 4-Item Hybrid Assessment of Mobility for mTBI (HAM-4-mTBI) for monitoring individuals with mTBI. Future work should validate the HAM-4-mTBI and investigate its utility for tracking progression throughout rehabilitation.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A409 ).

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.

Virtual reality-based interventions for the rehabilitation of vestibular and balance impairments post-concussion: a scoping review

BACKGROUND

Concussions and mild traumatic brain injuries are the most common causes of physical and cognitive disability worldwide. Concussion can result in post-injury vestibular and balance impairments that can present up to five years post initial concussion event, ultimately affecting many daily and functional activities. While current clinical treatment aims to reduce symptoms, the developing use of technology in everyday life has seen the emergence of virtual reality. Current literature has failed to identify substantial evidence regarding the use of virtual reality in rehabilitation. The primary aim of this scoping review is to identify, synthesise, and assess the quality of studies reporting on the effectiveness of virtual reality for the rehabilitation of vestibular and balance impairments post-concussion. Additionally, this review aims to summarise the volume of scientific literature and identify the knowledge gaps in current research pertaining to this topic.

METHODS

A scoping review of six databases (PubMed, Embase, CINAHL, ProQuest, SportDiscus, Scopus) and a grey literature (Google Scholar) was conducted using three key concepts (virtual reality, vestibular symptoms, and post-concussion). Data was charted from studies and outcomes were categorised into one of three categories: (1) balance; (2) gait; or (3) functional outcome measures. Critical appraisal of each study was conducted using the Joanna Briggs Institute checklists. A critical appraisal of each outcome measure was also completed utilising a modified GRADE appraisal tool to summarise the quality of evidence. Effectiveness was assessed using calculations of change in performance and change per exposure time.

RESULTS

Three randomised controlled trials, three quasi-experimental studies, three case studies, and one retrospective cohort study were ultimately included, using a thorough eligibility criteria. All studies were inclusive of different virtual reality interventions. The ten studies had a 10-year range and identified 19 different outcome measures.

CONCLUSION

The findings from this review suggests that virtual reality is an effective tool for the rehabilitation of vestibular and balance impairments post-concussion. Current literature shows sufficient but low level of evidence, and more research is necessary to develop a quantitative standard and to better understand appropriate dosage of virtual reality intervention.

Assessment of balance in people with mild traumatic brain injury using a balance systems model approach

PURPOSE

Measuring persistent imbalance after mTBI is challenging and may include subjective symptom-reporting as well as clinical scales. Clinical assessments for quantifying balance following mTBI have focused on sensory orientation. It is theorized that balance control goes beyond sensory orientation and also includes subdomains of anticipatory postural adjustments, reactive postural control, and dynamic gait. The Mini Balance Evaluation Systems Test (Mini-BESTest) is a validated balance test that measures balance according to these subdomains for a more comprehensive assessment. The purpose of this study was to compare Mini-BESTest total and subdomain scores after subacute mTBI with healthy controls.

METHODS

Symptomatic mTBI (n = 90, 20 % male, age=36.0 ± 12.0, 46.3.4 ± 22.1 days since injury) and healthy control (n = 45, 20 % male, age=35.4 ± 12.5) participants completed the Mini-BESTest for balance. Mini-BESTest between-group differences were evaluated using Wilcoxon rank-sum tests.

RESULTS

The mTBI group (Median[minimum,maximum]) had a significantly worse Mini-BESTest total score than the healthy controls (24[18,28] vs 27[23-28], p < 0.001). The mTBI group performed significantly worse in 3 of the 4 subdomains compared to the healthy controls: reactive postural control: 5[2-6] vs 6[3-6], p = 0.003; sensory orientation: 6[5,6] vs 6[6], p = 0.005; dynamic gait: 8[5-10] vs 9[8-10], p < 0.001. There was no significance difference between groups in the anticipatory postural adjustments domain (5[3-6] vs 5[3-6], p = 0.12).

CONCLUSIONS

The Mini-BESTest identified deficits in people with subacute mTBI in the total score and 3 out of 4 subdomains, suggesting it may be helpful to use in the clinic to identify balance subdomain deficits in the subacute mTBI population. In combination with self-reported assessments, the mini-BESTest may identify balance domain deficits in the subacute mTBI population and help guide treatment for this population.

Multi-domain assessment of sports-related and military concussion recovery: A scoping review

OBJECTIVE

This review explores the literature on multi-domain assessments used in concussion recovery, to inform evidence-based and ecologically valid return-to-play. It asks: What simultaneous, dynamic multi-domain paradigms are used to assess recovery of youth and adults following concussion?

METHODS

Five databases were searched (CINAHL, EMBASE, MEDLINE, PsycInfo, SPORTDiscus) until September 30, 2021. Records were limited to those published in peer-reviewed journals, in English, between 2002 and 2021. Included studies were required to describe the assessment of concussion recovery using dynamic paradigms (i.e., requiring sport-like coordination) spanning multiple domains (i.e., physical, cognitive, socio-emotional functioning) simultaneously.

RESULTS

7098 unique articles were identified. 64 were included for analysis, describing 36 unique assessments of 1938 concussed participants. These assessments were deconstructed into their constituent tasks: 13 physical, 17 cognitive, and one socio-emotional. Combinations of these "building blocks" formed the multi-domain assessments. Forty-six studies implemented level walking with a concurrent cognitive task. The most frequently implemented cognitive tasks were 'Q&A' paradigms requiring participants to answer questions aloud during a physical task.

CONCLUSIONS

A preference emerged for dual-task assessments, specifically combinations of level walking and Q&A tasks. Future research should balance ecological validity and clinical feasibility in multi-domain assessments, and work to validate these assessments for practice.

Neuromotor changes in participants with a concussion history can be detected with a custom smartphone app

Neuromotor dysfunction after a concussion is common, but balance tests used to assess neuromotor dysfunction are typically subjective. Current objective balance tests are either cost- or space-prohibitive, or utilize a static balance protocol, which may mask neuromotor dysfunction due to the simplicity of the task. To address this gap, our team developed an Android-based smartphone app (portable and cost-effective) that uses the sensors in the device (objective) to record movement profiles during a stepping-in-place task (dynamic movement). The purpose of this study was to examine the extent to which our custom smartphone app and protocol could discriminate neuromotor behavior between concussed and non-concussed participants. Data were collected at two university laboratories and two military sites. Participants included civilians and Service Members (N = 216) with and without a clinically diagnosed concussion. Kinematic and variability metrics were derived from a thigh angle time series while the participants completed a series of stepping-in-place tasks in three conditions: eyes open, eyes closed, and head shake. We observed that the standard deviation of the mean maximum angular velocity of the thigh was higher in the participants with a concussion history in the eyes closed and head shake conditions of the stepping-in-place task. Consistent with the optimal movement variability hypothesis, we showed that increased movement variability occurs in participants with a concussion history, for which our smartphone app and protocol were sensitive enough to capture.

R2Play development: Fostering user-driven technology that supports return-to-play decision-making following pediatric concussion

Objective

To design a multi-domain return-to-play assessment system (R2Play) for youth athletes with concussion.

Methods

The R2Play system was developed using an overarching user-centered approach, the Design Thinking Framework, and research activities included: 1) structured brainstorming within our research team, 2) interviews with clinician and youth sports coaches, 3) building a testable prototype, and 4) interface testing through cognitive walkthroughs with clinician partners.

Results

Clinician and coach participants provided feedback on the R2Play concept, which was integrated into the design process and provided future directions for research. Examples of feedback-driven design choices included reducing assessment time, increasing ecological validity by adding in background noise, and developing youth-friendly graphical results screens. Following refinement based on stakeholder feedback, the R2Play system was outlined in detail and a testable prototype was developed. It is made up of two parts: a clinician tablet, and a series of tablet "buttons" that display numbers and letters. Youth athletes run between the buttons to connect a "trail" in ascending alphanumeric order, 1-A-2-B, etc. Their performance across a series of levels of increasing difficulty is logged on the clinician tablet. Initial testing with five clinicians showed the system's interface to have excellent usability with a score of 81% (SD = 8.02) on the System Usability Scale.

Conclusion

Through this research, a prototype of the R2Play system was innovated and evaluated by clinician and coach stakeholders. Initial usability was excellent and directions for future iterations were highlighted. Outcomes suggest the potential benefits of using technologies to assist in complex clinical assessment, as well as utilizing a user-centered approach to design.

Reactive Balance Responses After Mild Traumatic Brain Injury: A Scoping Review

OBJECTIVE

Balance testing after concussion or mild traumatic brain injury (mTBI) can be useful in determining acute and chronic neuromuscular deficits that are unapparent from symptom scores or cognitive testing alone. Current assessments of balance do not comprehensively evaluate all 3 classes of balance: maintaining a posture; voluntary movement; and reactive postural response. Despite the utility of reactive postural responses in predicting fall risk in other balance-impaired populations, the effect of mTBI on reactive postural responses remains unclear. This review sought to (1) examine the extent and range of available research on reactive postural responses in people post-mTBI and (2) determine whether reactive postural responses (balance recovery) are affected by mTBI.

DESIGN

Scoping review.

METHODS

Studies were identified using MEDLINE, EMBASE, CINAHL, Cochrane Library, Dissertations and Theses Global, PsycINFO, SportDiscus, and Web of Science. Inclusion criteria were injury classified as mTBI with no confounding central or peripheral nervous system dysfunction beyond those stemming from the mTBI, quantitative measure of reactive postural response, and a discrete, externally driven perturbation was used to test reactive postural response.

RESULTS

A total of 4747 publications were identified, and a total of 3 studies (5 publications) were included in the review.

CONCLUSION

The limited number of studies available on this topic highlights the lack of investigation on reactive postural responses after mTBI. This review provides a new direction for balance assessments after mTBI and recommends incorporating all 3 classes of postural control in future research.

Exploring Vestibular Ocular Motor Screening in Adults With Persistent Complaints After Mild Traumatic Brain Injury

OBJECTIVE

The purpose of this study was to (1) explore differences in vestibular ocular motor screening (VOMS) symptoms between healthy adults and adults with persistent symptoms after mild traumatic brain injury (mTBI), and (2) explore the relationships between VOMS symptoms and other measures (self-reported vestibular symptoms, clinical measures of balance and gait, and higher-level motor ability tasks).

SETTING

Research laboratory setting.

PARTICIPANTS

Fifty-three persons with persistent symptoms (>3 weeks) following mTBI and 57 healthy controls were recruited. Eligibility for participation included being 18 to 50 years of age and free of medical conditions that may affect balance, with the exception of recent mTBI for the mTBI group.

DESIGN

Cross-sectional.

MAIN MEASURES

The primary outcomes were the VOMS symptom scores and near point of convergence (NPC) distance. Secondary outcomes included the Dizziness Handicap Inventory (DHI) total and subdomain scores, sway area, Functional Gait Analysis total score, gait speed, and modified Illinois Agility Task completion time, and Revised High-Level Mobility Assessment Tool total score.

RESULTS

The mTBI group reported more VOMS symptoms ( z range, -7.28 to -7.89) and a further NPC ( t = -4.16) than healthy controls (all P s < .001). DHI self-reported symptoms (total and all subdomain scores) were strongly associated with the VOMS symptom scores (rho range, 0.53-0.68; all P s < .001). No significant relationships existed between VOMS symptoms and other measures.

CONCLUSION

Significant group differences support the relevance of the VOMS for mTBI in an age-diverse sample with persistent symptoms. Furthermore, strong association with DHI symptoms supports the ability of the VOMS to capture vestibular complaints in this population.

Visio-Vestibular Deficits in Healthy Child and Adolescent Athletes

OBJECTIVE

To determine the relationship between patient characteristics and performance on the visio-vestibular examination (VVE) in a cohort of healthy youth athletes and explore the potential association between the VVE and other standardized concussion batteries.

DESIGN

Cross-sectional.

SETTING

Suburban middle and high school.

PATIENTS

One hundred ninety subjects age 11 to 18 enrolled before their respective scholastic sport season between August 2017 and March 2020.

ASSESSMENT OF INDEPENDENT VARIABLES

Patient age, sex, concussion history, comorbidities, hours of weekly exercise, Sport Concussion Assessment Tool, 5th edition (SCAT-5), King-Devick (K-D), Postconcussion Symptom Inventory (PCSI).

MAIN OUTCOME MEASURES

Visio-vestibular examination abnormalities (smooth pursuit, horizontal and vertical saccades, horizontal and vertical gaze stability, convergence, right and left monocular accommodation, complex tandem gait).

RESULTS

Overall, 29.5% of subjects had at least one of 9 VVE elements abnormal, 7.9% at least 2, and 3.2% at least 3. None of 72 comparisons of the VVE elements, when stratified by age, sex, concussion history, history of headaches, attention deficit hyperactivity disorder, learning issues, psychiatric problems, motion sickness, or weekly hours of exercise, reached significance using the Benjamini-Hochberg procedure at a false discovery rate of 5%. There were no significant associations between VVE elements and the SCAT-5, K-D, or PCSI.

CONCLUSIONS

The VVE is robust across multiple patient characteristics. Although healthy subjects may have one abnormal element, multiple abnormal elements are a less common feature, making multiple abnormal elements more indicative of concussion, highlighting the use of this assessment in the setting of injury. The VVE tests unique domains when compared with the PCSI, SCAT-5, and K-D.

Comparison of Azure Kinect overground gait spatiotemporal parameters to marker based optical motion capture

BACKGROUND

Instrumented measurement of spatiotemporal parameters during walking can provide valuable information on an individual's overall function and health. Efficient, inexpensive, and accurate measurement of overground walking spatiotemporal parameters would be a critical component of providing point-of-care assessments of gait function, concussion recovery, fall-risk, and cognitive decline. Depth cameras combined with skeleton pose tracking algorithms, such as the Microsoft Kinect with body tracking software, have been used to measure walking spatiotemporal parameters. However, the ability of the latest generation Microsoft Kinect sensor, the Azure Kinect, to accurately measure overground walking spatiotemporal parameters has not been evaluated in the literature.

RESEARCH QUESTION

The purpose of this work was to compare overground walking spatiotemporal parameters measurements from a 12 camera Vicon optical motion capture system to measurements of a single Azure Kinect with body tracking SDK (software development kit).

METHODS

Spatiotemporal parameters of overground walking were simultaneously collected on twenty young healthy participants. Stride length, stride time, step length and step width were derived from ankle joint center locations and measurements from the two instruments were compared using descriptive statistics, scatter plots, Pearson correlation analyses, and Bland-Altman analyses.

RESULTS

Pearson correlation coefficients were greater than 0.87 for all spatiotemporal parameters with most parameters demonstrating very strong (> 0.9) agreement. The mean of the differences for stride length between measurements was 35.6 mm for the left limb and 39.1 mm for the right limb, both of which are less than 3% of average stride length. Mean of the differences for step width and stride time were less than 2% and 1% of their averages respectively.

SIGNIFICANCE

A single Microsoft Azure Kinect with body tracking SDK can provide clinically relevant measurement of walking spatiotemporal parameters, providing accessible and objective measurements that can improve clinical decision making across a variety of patient populations.

Free-living gait does not differentiate chronic mTBI patients compared to healthy controls

Background

Physical function remains a crucial component of mild traumatic brain injury (mTBI) assessment and recovery. Traditional approaches to assess mTBI lack sensitivity to detect subtle deficits post-injury, which can impact a patient’s quality of life, daily function and can lead to chronic issues. Inertial measurement units (IMU) provide an opportunity for objective assessment of physical function and can be used in any environment. A single waist worn IMU has the potential to provide broad/macro quantity characteristics to estimate gait mobility, as well as more high-resolution micro spatial or temporal gait characteristics (herein, we refer to these as measures of quality). Our recent work showed that quantity measures of mobility were less sensitive than measures of turning quality when comparing the free-living physical function of chronic mTBI patients and healthy controls. However, no studies have examined whether measures of gait quality in free-living conditions can differentiate chronic mTBI patients and healthy controls. This study aimed to determine whether measures of free-living gait quality can differentiate chronic mTBI patients from controls.

Methods

Thirty-two patients with chronic self-reported balance symptoms after mTBI (age: 40.88 ± 11.78 years, median days post-injury: 440.68 days) and 23 healthy controls (age: 48.56 ± 22.56 years) were assessed for ~ 7 days using a single IMU at the waist on a belt. Free-living gait quality metrics were evaluated for chronic mTBI patients and controls using multi-variate analysis. Receiver operating characteristics (ROC) and Area Under the Curve (AUC) analysis were used to determine outcome sensitivity to chronic mTBI.

Results

Free-living gait quality metrics were not different between chronic mTBI patients and controls (all p > 0.05) whilst controlling for age and sex. ROC and AUC analysis showed stride length (0.63) was the most sensitive measure for differentiating chronic mTBI patients from controls.

Conclusions

Our results show that gait quality metrics determined through a free-living assessment were not significantly different between chronic mTBI patients and controls. These results suggest that measures of free-living gait quality were not impaired in our chronic mTBI patients, and/or, that the metrics chosen were not sensitive enough to detect subtle impairments in our sample.

Exploring Inertial-Based Wearable Technologies for Objective Monitoring in Sports-Related Concussion: A Single-Participant Report

OBJECTIVE

Challenges remain in sports-related concussion (SRC) assessment to better inform return to play. Reliance on self-reported symptoms within the Sports Concussion Assessment Tool means that there are limited data on the effectiveness of novel methods to assess a player's readiness to return to play. Digital methods such as wearable technologies may augment traditional SRC assessment and improve objectivity in making decisions regarding return to play.

METHODS

The participant was a male university athlete who had a recent history of SRC. The single-participant design consisted of baseline laboratory testing immediately after SRC, free-living monitoring, and follow-up supervised testing after 2 months. The primary outcome measures were from traditional assessment (eg, Sports Concussion Assessment Tool and 2-minute instrumented walk/gait test; secondary outcome measures were from remote (free-living) assessment with a single wearable inertial measurement unit (eg, for gait and sleep).

RESULTS

The university athlete (age = 20 years, height = 175 cm, weight = 77 kg [176.37 lb]) recovered and returned to play 20 days after SRC. Primary measures returned to baseline levels after 12 days. However, supervised (laboratory-based) wearable device assessment showed that gait impairments (increased step time) remained even after the athlete was cleared for return to play (2 months). Similarly, a 24-hour remote gait assessment showed changes in step time, step time variability, and step time asymmetry immediately after SRC and at return to play (1 month after SRC). Remote sleep analysis showed differences in sleep quality and disturbance (increased movement between immediately after SRC and once the athlete had returned to play [1 month after SRC]).

CONCLUSION

The concern about missed or delayed SRC diagnosis is growing, but methods to objectively monitor return to play after concussion are still lacking. This report showed that wearable device assessment offers additional objective data for use in monitoring players who have SRC. This work could better inform SRC assessment and return-to-play protocols.

IMPACT

Digital technologies such as wearable technologies can yield additional data that traditional self-report approaches cannot. Combining data from nondigital (traditional) and digital (wearable) methods may augment SRC assessment for improved return-to-play decisions.

LAY SUMMARY

Inertia-based wearable technologies (eg, accelerometers) may be useful to help augment traditional, self-report approaches to sports-related concussion assessment and management by better informing return-to-play protocols.

Gait Impairment in Traumatic Brain Injury: A Systematic Review

Introduction: Gait impairment occurs across the spectrum of traumatic brain injury (TBI); from mild (mTBI) to moderate (modTBI), to severe (sevTBI). Recent evidence suggests that objective gait assessment may be a surrogate marker for neurological impairment such as TBI. However, the most optimal method of objective gait assessment is still not well understood due to previous reliance on subjective assessment approaches. The purpose of this review was to examine objective assessment of gait impairments across the spectrum of TBI. Methods: PubMed, AMED, OVID and CINAHL databases were searched with a search strategy containing key search terms for TBI and gait. Original research articles reporting gait outcomes in adults with TBI (mTBI, modTBI, sevTBI) were included. Results: 156 citations were identified from the search, of these, 13 studies met the initial criteria and were included into the review. The findings from the reviewed studies suggest that gait is impaired in mTBI, modTBI and sevTBI (in acute and chronic stages), but methodological limitations were evident within all studies. Inertial measurement units were most used to assess gait, with single-task, dual-task and obstacle crossing conditions used. No studies examined gait across the full spectrum of TBI and all studies differed in their gait assessment protocols. Recommendations for future studies are provided. Conclusion: Gait was found to be impaired in TBI within the reviewed studies regardless of severity level (mTBI, modTBI, sevTBI), but methodological limitations of studies (transparency and reproducibility) limit clinical application. Further research is required to establish a standardised gait assessment procedure to fully determine gait impairment across the spectrum of TBI with comprehensive outcomes and consistent protocols.

Sex Differences in the Outcomes of Mild Traumatic Brain Injury in Children Presenting to the Emergency Department

Sex differences after concussion have been studied largely in high school and college athletes, often without reference to comparison groups without concussion. This study sought to evaluate sex differences in outcomes among all children and adolescents presenting to the Emergency Department (ED) for either mild traumatic brain injury (TBI) or orthopedic injury (OI), regardless of mechanism of injury. The study involved a concurrent cohort, prospective study design with longitudinal follow-up. Participants were eight to 16 years old with mild TBI (n = 143) or OI (n = 73). They were recruited and completed an initial assessment at EDs at two children's hospitals. They returned for a post-acute assessment within two weeks of injury and for follow-up assessments at three and six months. Outcomes included child and parent proxy ratings of somatic and cognitive symptoms, and standardized tests of cognitive functioning and balance. Sex did not moderate group differences in balance, fluid or crystallized cognitive ability, or child or parent proxy ratings of somatic or cognitive symptoms. Both parents and children reported more somatic symptoms in girls than boys, but in both groups. Compared with the OI group, the mild TBI group showed significantly lower fluid cognitive ability at the post-acute assessment and significantly higher somatic and cognitive symptoms according to both child and parent proxy ratings across the first two weeks post-injury. The results suggest that sex does not moderate the outcomes of mild TBI in a pediatric ED population. Previous research pointing to sex differences after concussion may reflect the lack of comparison groups, as well as a focus on adolescents and young adults and sport-related concussion. Future research should investigate whether sex moderates the outcomes of pediatric mild TBI in adolescents but not in pre-adolescent children.

Wearables in rugby union: A protocol for multimodal digital sports-related concussion assessment

Background

Pragmatic challenges remain in the monitoring and return to play (RTP) decisions following suspected Sports Related Concussion (SRC). Reliance on traditional approaches (pen and paper) means players readiness for RTP is often based on self-reported symptom recognition as a marker for full physiological recovery. Non-digital approaches also limit opportunity for robust data analysis which may hinder understanding of the interconnected nature and relationships in deficit recovery. Digital approaches may provide more objectivity to measure and monitor impairments in SRC. Crucially, there is dearth of protocols for SRC assessment and digital devices have yet to be tested concurrently (multimodal) in SRC rugby union assessment. Here we propose a multimodal protocol for digital assessment in SRC, which could be used to enhance traditional sports concussion assessment approaches.

Methods

We aim to use a repeated measures observational study utilising a battery of multimodal assessment tools (symptom, cognitive, visual, motor). We aim to recruit 200 rugby players (male n≈100 and female n≈100) from University Rugby Union teams and local amateur rugby clubs in the North East of England. The multimodal battery assessment used in this study will compare metrics between digital methods and against traditional assessment.

Conclusion

This paper outlines a protocol for a multimodal approach for the use of digital technologies to augment traditional approaches to SRC, which may better inform RTP in rugby union. Findings may shed light on new ways of working with digital tools in SRC. Multimodal approaches may enhance understanding of the interconnected nature of impairments and provide insightful, more objective assessment and RTP in SRC.

Clinical trial registration

NCT04938570. https://clinicaltrials.gov/ct2/results?cond=NCT04938570&term=&cntry=&state=&city=&dist=

Interadministrator Reliability of a Modified Instrumented Push and Release Test of Reactive Balance

CONTEXT

Traditional assessments of reactive balance require sophisticated instrumentation to ensure objective, highly repeatable paradigms. This instrumentation is clinically impractical. The Push and Release test (P&R) is a well-validated clinical test that examines reactive balance, and the application of wearable inertial measurement units (IMU) enables sensitive and objective assessment of this clinically feasible test. The P&R relies on administrator experience and may be susceptible to interadministration reliability concerns. The purpose of this study was to evaluate the interadministrator reliability of objective outcomes from an instrumented, modified version of the P&R test.

DESIGN

Crossover interadministrator design.

METHODS

Twenty healthy adults (20-35 y) completed the P&R in 4 directions with 2 different administrators. Measures quantified using IMUs included step latency, step length, and time to stability. Lean angle (LA) at release was used as a measure of administration consistency. The intraclass correlation coefficient (ICC) estimate was used to assess interadministrator reliability in each direction. To determine consistency of LA within and across administrators, we calculated the SDs for each rater by direction and the interadministrator reliability of LA using ICC.

RESULTS

Across individual directions, the ICC for agreement between raters ranged from .16 to .39 for step latency, from .52 to .62 for time to stability, and from .48 to .84 for step length. Summary metrics across all 4 directions produced higher ICC values. There was poor to moderate consistency in administration based on LA, but LA did not significantly affect any of the outcomes.

CONCLUSION

The modified P&R yields moderate interadministrator reliability and high validity. Summary metrics over all 4 directions (the maximum step latency, the median time to stability, and the median step length) are likely more reliable than direction-specific scores. Variations in body size should also be considered when comparing populations.

Sports related concussion: an emerging era in digital sports technology

Sports-related concussion (SRC) is defined as a mild traumatic brain injury (mTBI) leading to complex impairment(s) in neurological function with many seemingly hidden or difficult to measure impairments that can deteriorate rapidly without any prior indication. Growing numbers of SRCs in professional and amateur contact sports have prompted closer dialog regarding player safety and welfare. Greater emphasis on awareness and education has improved SRC management, but also highlighted the difficulties of diagnosing SRC in a timely manner, particularly during matches or immediately after competition. Therefore, challenges exist in off-field assessment and return to play (RTP) protocols, with current traditional (subjective) approaches largely based on infrequent snapshot assessments. Low-cost digital technologies may provide more objective, integrated and personalized SRC assessment to better inform RTP protocols whilst also enhancing the efficiency and precision of healthcare assessment. To fully realize the potential of digital technologies in the diagnosis and management of SRC will require a significant paradigm shift in clinical practice and mindset. Here, we provide insights into SRC clinical assessment methods and the translational utility of digital approaches, with a focus on off-field digital techniques to detect key SRC metrics/biomarkers. We also provide insights and recommendations to the common benefits and challenges facing digital approaches as they aim to transition from novel technologies to an efficient, valid, reliable, and integrated clinical assessment tool for SRC. Finally, we highlight future opportunities that digital approaches have in SRC assessment and management including digital twinning and the "digital athlete".

Anticipatory and reactive responses to underfoot perturbations during gait in healthy adults and individuals with a recent mild traumatic brain injury

BACKGROUND

Following mild traumatic brain injury, individuals often exhibit quantifiable gait deficits over flat surfaces, but little is known about how they control gait over complex surfaces. Such complex surfaces require precise neuromotor control to anticipate and react to small disturbances in walking surfaces, and mild traumatic brain injury-related balance deficits may adversely affect these gait adjustments.

METHODS

This study investigates anticipatory and reactive gait adjustments for expected and unexpected underfoot perturbations in healthy adults (n = 5) and individuals with mild traumatic brain injury (n = 5). Participants completed walking trials with random unexpected or expected underfoot perturbations from a mechanized shoe and inertial measurement units collected kinematic data from the feet and sternum. Linear mixed-effects models assessed the effects of segment, group, and their interaction on standardized difference of accelerations between perturbation and non-perturbation trials.

FINDINGS

Both groups demonstrated similar gait strategies when perturbations were unexpected. During late swing phase before expected perturbations, persons with mild traumatic brain injury exhibited greater lateral acceleration of their perturbed foot and less lateral movement of their trunk compared with unperturbed gait. Control participants exhibited less lateral foot acceleration and no difference in mediolateral trunk acceleration compared with unperturbed gait during the same period. A significant group*segment interaction (p < 0.001) during this part of the gait cycle suggests the groups adopted different anticipatory strategies for the perturbation.

INTERPRETATION

Individuals with mild traumatic brain injury may be adopting cautious strategies for expected perturbations due to persistent neuromechanical deficits stemming from their injury.

Saccade and Fixation Eye Movements During Walking in People With Mild Traumatic Brain Injury

Background: Clinical and laboratory assessment of people with mild traumatic brain injury (mTBI) indicate impairments in eye movements. These tests are typically done in a static, seated position. Recently, the use of mobile eye-tracking systems has been proposed to quantify subtle deficits in eye movements and visual sampling during different tasks. However, the impact of mTBI on eye movements during functional tasks such as walking remains unknown.

Objective: Evaluate differences in eye-tracking measures collected during gait between healthy controls (HC) and patients in the sub-acute stages of mTBI recovery and to determine if there are associations between eye-tracking measures and gait speed.

Methods: Thirty-seven HC participants and 67individuals with mTBI were instructed to walk back and forth over 10-m, at a comfortable self-selected speed. A single 1-min trial was performed. Eye-tracking measures were recorded using a mobile eye-tracking system (head-mounted infra-red Tobbii Pro Glasses 2, 100 Hz, Tobii Technology Inc. VA, United States). Eye-tracking measures included saccadic (frequency, mean and peak velocity, duration and distance) and fixation measurements (frequency and duration). Gait was assessed using six inertial sensors (both feet, sternum, right wrist, lumbar vertebrae and the forehead) and gait velocity was selected as the primary outcome. General linear model was used to compare the groups and association between gait and eye-tracking outcomes were explored using partial correlations.

Results: Individuals with mTBI showed significantly reduced saccade frequency (p = 0.016), duration (p = 0.028) and peak velocity (p = 0.032) compared to the HC group. No significant differences between groups were observed for the saccade distance, fixation measures and gait velocity (p > 0.05). A positive correlation was observed between saccade duration and gait velocity only for participants with mTBI (p = 0.025).

Conclusion: Findings suggest impaired saccadic eye movement, but not fixations, during walking in individuals with mTBI. These findings have implications in real-world function including return to sport for athletes and return to duty for military service members. Future research should investigate whether or not saccade outcomes are influenced by the time after the trauma and rehabilitation.

An inertial sensor-based algorithm for turning detection during gait

Patients with Parkinson's disease (PD) can be divided into two subtypes based on clinical features, namely tremor-dominant (TD) and postural instability and gait difficulty (PIGD). Detection of PIGD symptoms is crucial for early diagnosis of PD and timely clinical intervention. However, patients at the early stage may not exhibit obvious motor dysfunctions during normal straight walking leading to difficulties in PD identification. Researchers have found that patients would show significant motor deteriorations in turning due to their cognition limitation. Therefore, turning detection is essential for quantitative motion analysis in the gait assessment of PD patients. In this study, we proposed a novel inertial-sensor-based algorithm for turning detection. Ten healthy young participants were enrolled in the experiment where they were required to walk along a 7-meter pathway with two 180 degree turns at their comfortable walking speed. Five inertial sensors were attached to the upper trunk, the shank and the foot of both legs. The algorithm performance was validated using an optical motion capture system for reference and two sensor combination options (upper trunk and shank sensors, upper trunk and foot sensors) were compared. The results showed that the proposed algorithm achieved accuracy over 98% for identifying the turning state of both legs. The integration of the upper trunk and foot sensors had no significant effect on the detection accuracy compared to that with the use of the upper trunk and shank sensors. Our algorithm has the potential to be implemented in the motion analysis model for complicated gait tasks, which has great potential in the early diagnosis of PIGD.

The effects of a secondary task on gait in axial spondyloarthritis

Studies on the effects of dual tasking in patients with chronic inflammatory rheumatic diseases are limited. The aim of this study was to assess dual tasking while walking in patients with axial spondyloarthritis (axSpA) in comparison to healthy controls. Thirty patients with axSpA and thirty healthy controls underwent a 10-m walk test at a self-selected comfortable walking speed in single- and dual-task conditions. Foot-worn inertial sensors were used to compute spatiotemporal gait parameters. Analysis of spatiotemporal gait parameters showed that the secondary manual task negatively affected walking performance in terms of significantly decreased mean speed (p < 0.001), stride length (p < 0.001) and swing time (p = 0.008) and increased double support (p = 0.002) and stance time (p = 0.008). No significant interaction of group and condition was observed. Both groups showed lower gait performance in dual task condition by reducing speed, swing time and stride length, and increasing double support and stance time. Patients with axSpA were not more affected by the dual task than matched healthy controls, suggesting that the secondary manual task did not require greater attention in patients with axSpA. Increasing the complexity of the walking and/or secondary task may increase the sensitivity of the dual-task design to axial spondyloarthritis.

Potential Mechanisms of Acute Standing Balance Deficits After Concussions and Subconcussive Head Impacts: A Review

Standing balance deficits are prevalent after concussions and have also been reported after subconcussive head impacts. However, the mechanisms underlying such deficits are not fully understood. The objective of this review is to consolidate evidence linking head impact biomechanics to standing balance deficits. Mechanical energy transferred to the head during impacts may deform neural and sensory components involved in the control of standing balance. From our review of acute balance-related changes, concussions frequently resulted in increased magnitude but reduced complexity of postural sway, while subconcussive studies showed inconsistent outcomes. Although vestibular and visual symptoms are common, potential injury to these sensors and their neural pathways are often neglected in biomechanics analyses. While current evidence implies a link between tissue deformations in deep brain regions including the brainstem and common post-concussion balance-related deficits, this link has not been adequately investigated. Key limitations in current studies include inadequate balance sampling duration, varying test time points, and lack of head impact biomechanics measurements. Future investigations should also employ targeted quantitative methods to probe the sensorimotor and neural components underlying balance control. A deeper understanding of the specific injury mechanisms will inform diagnosis and management of balance deficits after concussions and subconcussive head impact exposure.

Associations Between Neurochemistry and Gait Performance Following Concussion in Collegiate Athletes

OBJECTIVE

To evaluate the strength of associations between single-task and dual-task gait measures and posterior cingulate gyrus (PCG) neurochemicals in acutely concussed collegiate athletes.

SETTING

Participants were recruited from an NCAA Division 1 University.

PARTICIPANTS

Nineteen collegiate athletes acutely (<4 days) following sports-related concussion.

DESIGN

We acquired magnetic resonance spectroscopy (MRS) in the PCG and gait performance measurements in the participants, acutely following concussion. Linear mixed-effects models were constructed to measure the effect of gait performance, in the single- and dual-task settings, and sex on the 6 neurochemicals quantified with MRS in mmol. Correlation coefficients were also calculated to determine the direction and strength of the relationship between MRS neurochemicals and gait performance, postconcussion symptom score, and number of previous concussions.

MAIN MEASURES

Average gait speed, average cadence, N-acetyl aspartate, choline, myo-inositol, glutathione, glutamate plus glutamine, and creatine.

RESULTS

Single-task gait speed (P = .0056) and cadence (P = .0065) had significant effects on myo-inositol concentrations in the PCG, independent of sex, in concussed collegiate athletes. Single-task cadence (P = .047) also had a significant effect on glutathione in the PCG. No significant effects were observed between dual-task gait performance and PCG neurochemistry.

CONCLUSIONS

These findings indicate that increased concentrations of neuroinflammatory markers in the PCG are associated with slower single-task gait performance within 4 days of sports-related concussion.

Resting state functional connectivity responses post-mild traumatic brain injury: a systematic review

Mild traumatic brain injuries (mTBI) are associated with functional network connectivity alterations throughout recovery. Yet, little is known about the adaptive or maladaptive nature of post-mTBI connectivity and which networks are predisposed to altered function and adaptation. The objective of this review was to determine functional connectivity changes post-mTBI and to determine the adaptive or maladaptive nature of connectivity through direct comparisons of connectivity and behavioral data. Literature was systematically searched and appraised for methodological quality. A total of 16 articles were included for review. There was conflicting evidence of post-mTBI connectivity responses as decreased connectivity was noted in 4 articles, 6 articles reported increased connectivity, 5 reported a mixture of increased and decreased connectivity, while 1 found no differences in connectivity. Supporting evidence for adaptive post-mTBI increases in connectivity were found, particularly in the frontoparietal, cerebellar, and default mode networks. Although initial results are promising, continued longitudinal research that systematically controls for confounding variables and that standardizes methodologies is warranted to adequately understand the neurophysiological recovery trajectory of mTBI.

Static and Dynamic Cognitive Performance in Youth and Collegiate Athletes With Concussion

OBJECTIVE

To determine if individuals with a concussion demonstrate altered cognitive performance while standing still or while walking relative to uninjured controls.

DESIGN

Cross-sectional.

SETTING

Sports-medicine clinic.

PARTICIPANTS

Youth and collegiate athletes diagnosed with a concussion, assessed within 10 days of injury, and a group of uninjured control subjects.

INDEPENDENT VARIABLES

Concussion and control groups.

MAIN OUTCOME MEASURES

Participants stood still for 30 seconds while completing a cognitive task (spelling words backward, serial subtraction, or reverse month recitation) and completed a similar set of cognitive tasks while walking. Our primary outcome variables were (1) overall cognitive task performance (accuracy) and (2) the total number of task items completed during testing (completion rate) during standing and walking conditions.

RESULTS

One hundred ninety-one participants completed the study: 94 with concussion (tested mean = 5.1 ± 2.9 days postconcussion; 51% female; mean age = 17.1 ± 3.3 years) and 97 control subjects (40% female; mean age = 17.5 ± 2.1 years). The concussion group completed significantly fewer responses than the control group while standing still (37.3 ± 14.5 vs 45.1 ± 17.6 responses; P = 0.03) and while walking (22.7 ± 7.5 vs 33.6 ± 13.4 responses; P < 0.001). They were also significantly less accurate at spelling words backward (81.2 ± 28.6% correct vs 89.8 ± 15.0% correct; P = 0.049) and reciting months in reverse order (95.8 ± 10.4% correct vs 98.2 ± 4.2% correct; P = 0.034) while walking.

CONCLUSIONS

Athletes displayed lower cognitive task accuracy rates after concussion compared with control subjects during backward spelling and reverse month recitation tasks while walking but similar levels of accuracy while standing. Assessment of cognitive performance during dynamic tasks may be a clinically viable method to evaluate post-concussion deficits.

Head and Body Dyskinesia During Gait in Tactical Athletes With Vestibular Deficit Following Concussion

Background: Vestibular deficit is common following concussion and may affect gait. The purpose of this study was to investigate differences in head and pelvic center of mass (COM) movement during gait in military tactical athletes with and without concussion-related central vestibular impairment.

Material and Methods: 24 patients with post-concussion vestibular impairment (20 males, 4 females; age: 31.7 ± 7.9 years; BMI: 27.3 ± 3.3) and 24 matched controls (20 males, 4 females; age: 31.8 ± 6.4 years; BMI: 27.2 ± 2.6) were included in the analyses. Three-dimensional head and pelvic displacement and velocities were collected at a 1.0 m/s standardized treadmill walking speed and assessed using Statistical Parametric Mapping t-tests. Maximum differences (d_max) between groups were reported for all significant kinematic findings.

Results: The Vestibular group demonstrated significantly diminished anteroposterior head excursions (d_max = 2.3 cm, p = 0.02) and slower anteroposterior (d_max = 0.37 m/s, p = 0.01), mediolateral (d_max = 0.47 m/s, p = 0.02) and vertical (d_max = 0.26 m/s, p < 0.001) velocities during terminal stance into pre-swing phases compared to the Control group. Vertical pelvic excursion was significantly increased in midstance (d_max = 2.4 cm, p = 0.03) and mediolaterally during pre- to initial-swing phases (d_max = 7.5 cm, p < 0.001) in the Vestibular group. In addition, pelvic velocities of the Vestibular group were higher mediolaterally during midstance (d_max = 0.19 m/s, p = 0.02) and vertically during post-initial contact (d_max = 0.14 m/s, p < 0.001) and pre-swing (d_max = 0.16 m/s, p < 0.001) compared to the Control group.

Significance: The Vestibular group demonstrated a more constrained head movement strategy during gait compared with Controls, a finding that is likely attributed to a neurological impairment of visual-vestibular-somatosensory integration.

Loss of Motor Stability After Sports-Related Concussion: Opportunities for Motor Learning Strategies to Reduce Musculoskeletal Injury Risk

Current best practices to direct recovery after sports-related concussion (SRC) typically require asymptomatic presentation at both rest and during a graduated exercise progression, and cognitive performance resolution. However, this standard of care results in a significantly elevated risk for musculoskeletal (MSK) injury after return-to-sport (RTS). The elevated risk is likely secondary to, in part, residual neurophysiological and dual-task motor stability deficits that remain despite RTS. These deficits present as a loss of autonomous control of gait and posture and an increased need for cognition for motor stability. Thus, the incorporation of strategies that can enhance motor stability and restore autonomous control of gait and posture during SRC recovery and RTS progression may facilitate a reduction of the elevated risk of secondary MSK injury. We provide a theoretical framework for the application of motor learning principles to restore autonomous gait and postural stability after SRC via incorporation, or targeted manipulation, of external focus, enhanced expectations, autonomy support, practice schedule variability, and dual-task strategies during rehabilitation and RTS training.

Relating Self-Reported Balance Problems to Sensory Organization and Dual-Tasking in Chronic Traumatic Brain Injury

BACKGROUND

Individuals who have experienced a traumatic brain injury (TBI) often have residual balance problems. It remains unclear whether these balance problems are driven by vestibular dysfunction or gait automaticity deficits, particularly in the chronic stages of TBI recovery, because most studies include only acute/subacute cases.

OBJECTIVES

Compare performance on the Sensory Organization Test vestibular score and Dual-Task test in individuals with and without subjective balance problems at least 1 year after a TBI. Investigate the ability of each test to predict perceived balance problems.

DESIGN

Prospective cohort study.

SETTING

Rehabilitation department within a single institution.

PARTICIPANTS

Fifty adults (21-71 years) with a history of mild, moderate, or severe TBI 1 to 5 years following nonpenetrating TBI.

INTERVENTIONS

N/A.

METHODS

Measures included the Dual-Task test, Sensory Organization Test, Neurobehavioral Symptom Inventory, Dizziness Handicap Inventory, and assessments of four cognitive domains and depression. Participants who endorsed "feeling dizzy" and "loss of balance" on the Neurobehavioral Symptom Inventory were classified as symptomatic (n = 26) and others as asymptomatic (n = 24). T-tests, chi-square, and regression analyses predicting the Dizziness Handicap Inventory total score were performed.

RESULTS

Dual-task gait cost was negatively associated with the Dizziness Handicap Inventory (P = .044), controlling for depression and gender, whereas vestibular scores failed to predict balance-related disability. Symptomatic individuals endorsed more balance problems (P < .001) and depression symptoms (P = .007), had poorer dual-task cognitive output (P = .036), and slower dual-task gait velocity (P = .036) than asymptomatic participants. Groups did not differ on Sensory Organization Test scores.

CONCLUSIONS

The nature of balance problems in chronic TBI may be related to automaticity of gait. These findings suggest that patients in the chronic stages of TBI may benefit from dual-task assessments and interventions. Balance rehabilitation should be tailored to patient needs and assess cognition and affect.

Transitory kinesiophobia after sport-related concussion and its correlation with reaction time

OBJECTIVES

To examine kinesiophobia (i.e. fear of movement) among adolescent athletes with concussion compared to controls, and correlations of kinesiophobia with symptoms and reaction time.

DESIGN

Prospective cohort study.

METHODS

We evaluated 49 adolescent athletes twice. The concussion group was assessed within 14 days of injury and at return-to-play clearance. The control group was tested initially and approximately 28 days later. Participants completed Tampa Scale of Kinesiophobia, Post-Concussion Symptom Inventory, and clinical reaction time assessments.

RESULTS

We included 32 concussion participants (15 ± 2 years; 50% female) and 17 controls (16 ± 1 years; 47% female). Acutely (<14 days post-injury), the concussion group reported greater Tampa Scale of Kinesiophobia scores (38.5 ± 5.4 vs. 29.4 ± 6.7; p < 0.001; Cohen's d = 1.54), and a greater proportion of "high" (≥37) scores than controls (69% vs. 6%; p < 0.001). At return-to-play, there were no significant between-group differences (33.3 ± 6.5 vs. 30.8 ± 7.4; p = 0.23; Cohen's d = 0.36); 28% of the concussion group reported "high" Tampa Scale of Kinesiophobia scores. At return-to-play, kinesiophobia was significantly/moderately correlated with clinical reaction time for the concussion group (r = 0.50; p = 0.01).

CONCLUSIONS

Adolescents recovering from concussion commonly reported high kinesiophobia initially postconcussion, while 28% continued to report high kinesiophobia at return-to-play clearance. Additionally, a correlation between Tampa Scale of Kinesiophobia scores and clinical reaction time was observed for the concussion group. This finding would benefit from further study to determine potential perception-behavior relationships following concussion.

Algorithm based on one monocular video delivers highly valid and reliable gait parameters

Despite its paramount importance for manifold use cases (e.g., in the health care industry, sports, rehabilitation and fitness assessment), sufficiently valid and reliable gait parameter measurement is still limited to high-tech gait laboratories mostly. Here, we demonstrate the excellent validity and test–retest repeatability of a novel gait assessment system which is built upon modern convolutional neural networks to extract three-dimensional skeleton joints from monocular frontal-view videos of walking humans. The validity study is based on a comparison to the GAITRite pressure-sensitive walkway system. All measured gait parameters (gait speed, cadence, step length and step time) showed excellent concurrent validity for multiple walk trials at normal and fast gait speeds. The test–retest-repeatability is on the same level as the GAITRite system. In conclusion, we are convinced that our results can pave the way for cost, space and operationally effective gait analysis in broad mainstream applications. Most sensor-based systems are costly, must be operated by extensively trained personnel (e.g., motion capture systems) or—even if not quite as costly—still possess considerable complexity (e.g., wearable sensors). In contrast, a video sufficient for the assessment method presented here can be obtained by anyone, without much training, via a smartphone camera.

The Smart-Insole Dataset: Gait Analysis Using Wearable Sensors with a Focus on Elderly and Parkinson's Patients

Gait analysis is crucial for the detection and management of various neurological and musculoskeletal disorders. The identification of gait events is valuable for enhancing gait analysis, developing accurate monitoring systems, and evaluating treatments for pathological gait. The aim of this work is to introduce the Smart-Insole Dataset to be used for the development and evaluation of computational methods focusing on gait analysis. Towards this objective, temporal and spatial characteristics of gait have been estimated as the first insight of pathology. The Smart-Insole dataset includes data derived from pressure sensor insoles, while 29 participants (healthy adults, elderly, Parkinson’s disease patients) performed two different sets of tests: The Walk Straight and Turn test, and a modified version of the Timed Up and Go test. A neurologist specialized in movement disorders evaluated the performance of the participants by rating four items of the MDS-Unified Parkinson’s Disease Rating Scale. The annotation of the dataset was performed by a team of experienced computer scientists, manually and using a gait event detection algorithm. The results evidence the discrimination between the different groups, and the verification of established assumptions regarding gait characteristics of the elderly and patients suffering from Parkinson’s disease.

Impaired motor control after sport-related concussion could increase risk for musculoskeletal injury: Implications for clinical management and rehabilitation

This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion (SRC) to increased risk for musculoskeletal injury. Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts. A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk. Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task. Motor control is inclusive of motor planning and motor learning. If sensory information is not accurately perceived or there is interference with sensory information processing and cognition, motor function will be altered, and an athlete may become vulnerable to injury during sport participation. Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria, including a normal neurological examination, resolution of symptoms, and return to baseline function on traditional concussion testing. In conjunction, altered motor function is demonstrated after SRC in muscle activation and force production, movement patterns, balance/postural stability, and motor task performance, especially performance of a motor task paired with a cognitive task (i.e., dual-task condition). The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.

Impaired eye tracking is associated with symptom severity but not dynamic postural control in adolescents following concussion

PURPOSE

The purpose of the study was to (1) examine the relationship between self-reported symptoms and concussion-related eye tracking impairments, and (2) compare gait performance between (a) adolescents with a concussion who have normal eye tracking, (b) adolescents with a concussion who have abnormal eye tracking, and (c) healthy controls.

METHODS

A total of 30 concussed participants (age: 14.4 ± 2.2 years, mean ± SD, 50% female) and 30 controls (age: 14.2 ± 2.2 years, 47% female) completed eye tracking and gait assessments. The BOX score is a metric of pupillary disconjugacy, with scores <10 classified as normal and ≥10 abnormal. Symptoms were collected using the Post-Concussion Symptom Scale (PCSS), and gait speed was measured with triaxial inertial measurement units. We conducted a linear regression to examine the relationship between PCSS and BOX scores and a two-way mixed effects analysis of variance to examine the effect of group (abnormal BOX, normal BOX, and healthy control) on single- and dual-task gait speed.

RESULTS

There was a significant association between total PCSS score and BOX score in the concussion group (β = 0.16, p = 0.004, 95% confidence interval (95%CI): 0.06‒0.27), but not in the control group (β = 0.21, p = 0.08, 95%CI: -0.03 to 0.45). There were no significant associations between PCSS symptom profiles and BOX scores in the concussion or control groups. There were also no significant differences in single-task (Abnormal: 1.00 ± 0.14 m/s; Normal: 1.11 ± 0.21 m/s; Healthy: 1.14 ± 0.18 m/s; p = 0.08) or dual-task (Abnormal: 0.77 ± 0.15 m/s; Normal: 0.84 ± 0.21 m/s; Healthy: 0.90 ± 0.18 m/s; p = 0.16) gait speed.

CONCLUSION

The concussed group with impaired eye tracking reported higher total symptom severity, as well as worse symptom severity across the 5 PCSS symptom domain profiles. However, eye tracking deficits did not appear to be driven by any particular symptom domain. While not statistically significant, the slower gait speeds in those with abnormal BOX scores may still be clinically relevant since gait-related impairments may persist beyond clinical recovery.

Quantitative Multimodal Assessment of Concussion Recovery in Youth Athletes

OBJECTIVE

To evaluate recovery trajectories among youth athletes with a concussion and healthy controls across different domains using a quantitative and multifaceted protocol.

STUDY DESIGN

Prospective repeated measures.

PARTICIPANTS

Youth athletes diagnosed with a concussion between the ages of 8 and 18 years were evaluated (1) within 10 days after injury, (2) approximately 3 weeks after injury, and (3) after return-to-play clearance. Control participants completed the same protocol.

SETTING

Sport concussion clinic.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Participants underwent a multifaceted protocol that assessed symptoms (postconcussion symptom scale [PCSS]), dual-task gait, event-related potentials (ERPs), and eye tracking.

RESULTS

Sixty-seven athletes participated: 36 after concussion (age = 14.0 ± 2.6 years; 44% female) and 31 controls (age = 14.6 ± 2.2 years; 39% female). Concussion symptoms were higher for the concussion group compared with controls at the first (PCSS = 31.7 ± 18.8 vs 1.9 ± 2.9; P < 0.001) and second time points (PCSS = 10.8 ± 11.2 vs 1.8 ± 3.6; P = 0.001) but resolved by the final assessment (PCSS = 1.7 ± 3.6 vs 2.0 ± 3.8; P = 0.46). The concussion group walked slower during dual-task gait than controls at all 3 tests including after return-to-play clearance (0.83 ± 0.19 vs 0.95 ± 0.15 m/s; P = 0.049). There were no between-group differences for ERP connectivity or eye tracking. Those with concussions had a decrease in ERP connectivity recovery over the 3 time points, whereas control participants' scores increased (concussion Δ = -8.7 ± 28.0; control Δ = 13.9 ± 32.2; χ2 = 14.1, P = 0.001).

CONCLUSIONS

Concussion is associated with altered dual-task gait speeds after resolution of concussion symptoms, but ERP and eye tracking measures did not demonstrate between-group differences across time. Some objective approaches to concussion monitoring may support with identifying deficits after concussion, but further work is required to delineate the role of gait, electrophysiological, and eye tracking methods for clinical decision-making.

Tandem gait test performance in healthy, physically active adults: Clinical implications for concussion evaluation

OBJECTIVES

To identify factors affecting performance on the tandem gait test in healthy, physically active adults.

DESIGN

Cross-sectional.

METHODS

Participants completed the tandem gait test according to Sport Concussion Assessment Tool 3 (SCAT3) guidelines. Dependent variables included time for best trial (initial 3m, turn, final 3m and total) and whether the trial was "pass" or "fail". Independent variables included sex, concussion history, foot length, height and total number of trials.

RESULTS

55% (35/64) of participants passed the first trial of the tandem gait test; 19% (12/64) had a best time <14s. Sex and concussion history did not affect performance (p>0.05). There were no differences in turn times for those with and without a history of concussion (t=0.26, p=0.80). The number of trials was not significantly correlated with best time (þ=-0.04, p=0.74). There were low (þ=-0.31) to negligible (þ<0.30) correlations between foot length, height and all portions of the test. There was more variability in times for the turn (COV=27%) than during the straight portions (COV=18%).

CONCLUSIONS

Current recommendations for the tandem gait test led to a high false-positive rate in healthy, physically active adults. Sex, concussion history, number of trials and foot length had little to no influence on scores on the test. Turning times were more variable than times on the straight portions of the test. Clinicians may use these results as a guideline when interpreting performance on the tandem gait test in healthy physically active adults.

The Influence of Cognitive Dual Tasks on Concussion Balance Test Performance

OBJECTIVE

To determine the influence of a cognitive dual task on postural sway and balance errors during the Concussion Balance Test (COBALT).

METHODS

Twenty healthy adults (12 females, eight males; aged 21.95 ± 3.77 years; height = 169.95 ± 9.95 cm; weight = 69.58 ± 15.03 kg) partook in this study and completed single- and dual-task versions of a reduced COBALT.

RESULTS

Sway velocity decreased during dual-task head rotations on foam condition (p = .021, ES = -0.57). A greater number of movement errors occurred during dual-task head rotations on firm surface (p = .005, ES = 0.71), visual field flow on firm surface (p = .008, ES = 0.68), and head rotations on foam surface (p < .001, ES = 1.61) compared with single-task conditions. Cognitive performance was preserved throughout different sensory conditions of the COBALT (p = .985).

DISCUSSION

Cognitive dual tasks influenced postural control and destabilized movements during conditions requiring advanced sensory integration and reweighting demands. Dual-task versions of the COBALT should be explored as a clinical tool to identify residual deficits past the acute stages of concussion recovery.

Performance during dual-task walking in a corridor after mild traumatic brain injury: A potential functional marker to assist return-to-function decisions

Objective: To compare the performance of participants with mTBI and healthy control on locomotor-cognitive dual-tasks in a corridor with limited technology.Design: Prospective study of twenty participants with mTBI (10 women; 22.10 ± 2.97 years; 70.9 ± 22.31 days post-injury), and 20 sex- and age-matched control participants (10 women; 22.55 ± 2.72 years).Methods: Participants performed six different dual-tasks combining locomotor tasks (level-walking, obstacle-crossing, and tandem gait) and cognitive tasks (counting backwards and verbal fluency). Symptoms and neuropsychological performance were also assessed.Results: No differences between groups were found for symptoms and neuropsychological measures. For gait speed, the group effect was not significant, but a significant group X cognitive task interaction was found, revealing a tendency toward slower gait speed in the mTBI group during dual-task conditions. A significantly greater dual-task cost for gait speed was found for the mTBI group. Although no statistically significant differences in cognitive performance were observed during dual-tasks, the mTBI group subjectively reported being significantly less concentrated.Conclusion: The present study revealed that in persons who seem to have well recovered after mTBI, on average 71 days post-injury, alterations in gait are detectable using a simple, "low-tech," corridor-based dual-task walking assessment.