Sensor-Based Balance Measures Outperform Modified Balance Error Scoring System in Identifying Acute Concussion

Instrumented Static and Reactive Balance in Collegiate Athletes: Normative Values and Minimal Detectable Change

CONTEXT

Wearable sensors are increasingly popular in concussion research because of their objective quantification of subtle balance deficits. However, normative data and minimal detectable change (MDC) values are necessary to serve as references for diagnostic use and tracking longitudinal recovery.

OBJECTIVE

To identify normative and MDC values for instrumented static- and reactive-balance tests, an instrumented static mediolateral (ML) root mean square (RMS) sway standing balance assessment and the instrumented, modified push and release (I-mP&R), respectively.

DESIGN

Cross-sectional study.

SETTING

Clinical setting.

PATIENTS OR OTHER PARTICIPANTS

Normative static ML RMS sway and I-mP&R data were collected on 377 (n = 184 female) healthy National Collegiate Athletic Association Division I athletes at the beginning of their competitive seasons. Test-retest data were collected in 36 healthy control athletes based on standard recovery timelines after concussion.

MAIN OUTCOME MEASURE(S)

Descriptive statistics, intraclass correlation coefficients (ICCs), and MDC values were calculated for primary outcomes of ML RMS sway in a static double-limb stance on firm ground and a foam block, and time to stability and latency from the I-mP&R in single- and dual-task conditions.

RESULTS

Normative outcomes across static ML RMS sway and I-mP&R were sensitive to sex and type of footwear. Mediolateral RMS sway demonstrated moderate reliability in the firm condition (ICC = 0.73; MDC = 2.7 cm/s2) but poor reliability in the foam condition (ICC = 0.43; MDC = 11.1 cm/s2). Single- and dual-task times to stability from the I-mP&R exhibited good reliability (ICC = 0.84 and 0.80, respectively; MDC = 0.25 and 0.29 seconds, respectively). Latency from the I-mP&R had poor to moderate reliability (ICC = 0.38 and 0.55; MDC = 107 and 105 milliseconds).

CONCLUSIONS

Sex-matched references should be used for instrumented static- and reactive-balance assessments. Footwear may explain variability in static ML RMS sway and time to stability of the I-mP&R. Moderate-to-good reliability suggests time to stability from the I-mP&R and ML RMS static sway on firm ground can be used for longitudinal assessments.

An Augmented Reality Rifle Qualification Test for Return-to-Duty Assessment in Service Members

INTRODUCTION

Variability in return-to-duty (RTD) decision-making following mild traumatic brain injury (mTBI) is a threat to troop readiness. Current RTD assessments lack military-specific tasks and quantitative outcomes to inform stakeholders of a service member's (SM) capacity to successfully perform military duties. Augmented reality (AR), which places digital assets in a user's physical environment, provides a technological vehicle to deliver military-relevant tasks to a SM to be used in the RTD decision-making process. In addition to delivering digital content, AR headsets provide biomechanical data that can be used to assess the integrity of the central nervous system in movement control following mTBI. The objective of this study was to quantify cognitive and motor performance on an AR rifle qualification test (RQT) in a group of neurologically healthy military SMs.

MATERIALS AND METHODS

Data were collected from 111 healthy SMs who completed a basic (single-task) and complex (dual-task) RQT with a simulated M4 rifle. The complex scenario required the SM to perform the RQT while simultaneously answering arithmetic problems. Position data from the AR headset were used to capture postural sway, and the built-in microphone gathered responses to the arithmetic problems.

RESULTS

There were no differences in the number of targets hit, trigger pull reaction time, and transition time from kneeling to standing between the basic and complex scenarios. A significant worsening in postural sway following kneel-to-stand transition was observed in the complex scenario. The average reaction time to answer the arithmetic problems was nearly 2 times slower than the average reaction time to pull the trigger to a displayed target in the complex scenario.

CONCLUSION

The complex scenario provoked dual-task interference in SMs as evidenced by worsening postural sway and reaction time differences between the cognitive and motor tasks. An AR RQT provides objective and quantitative outcomes during a military-specific task. Greater precision in evaluating cognitive and motor performance during a military-relevant task has the potential to aid in the detection and management of SMs and their RTD following MTBI.

Instrumented Balance Error Scoring System in Children and Adolescents-A Cross Sectional Study

Background: The Balance Error Scoring System (BESS) is a commonly used method for clinically evaluating balance after traumatic brain injury. The utilization of force plates, characterized by their cost-effectiveness and portability, facilitates the integration of instrumentation into the BESS protocol. Despite the enhanced precision associated with instrumented measures, there remains a need to determine the clinical significance and feasibility of such measures within pediatric cohorts. Objective: To report a comprehensive set of posturographic measures obtained during instrumented BESS and to examine the concurrent validity, reliability, and feasibility of instrumented BESS in the pediatric point of care setting. Methods: Thirty-seven participants (18 female; aged 13.32 ± 3.31 years) performed BESS while standing on a force plate to simultaneously compute stabilometric measures (instrumented BESS). Ellipse area (EA), path length (PL), and sway velocity (VM) were obtained for each of the six BESS positions and compared with the respective BESS scores. Additionally, the effects of sex and age were explored. A second BESS repetition was performed to evaluate the test-retest reliability. Feedback questionnaires were handed out after testing to evaluate the feasibility of the proposed protocol. Results: The BESS total score was 20.81 ± 6.28. While there was no statistically significant age or sex dependency in the BESS results, instrumented posturography demonstrated an age dependency in EA, VM, and PL. The one-leg stance on a soft surface resulted in the highest BESS score (8.38 ± 1.76), EA (218.78 cm2 ± 168.65), PL (4386.91 mm ± 1859.00), and VM (21.93 mm/s ± 9.29). The Spearman's coefficient displayed moderate to high correlations between the EA (rs = 0.429-0.770, p = 0.001-0.009), PL (rs = 0.451-0.809, p = 0.001-0.006), and VM (rs = 0.451-0.809, p = 0.001-0.006) when compared with the BESS scores for all testing positions, except for the one-leg stance on a soft surface. The BESS total score significantly correlated during the first and second repetition (rs = 0.734, p ≤ 0.001), as did errors during the different testing positions (rs = 0.489-0.799, p ≤ 0.001-0.002), except during the two-legged stance on a soft surface. VM and PL correlated significantly in all testing positions (rs = 0.465-0.675, p ≤ 0.001-0.004; (rs = 0.465-0.675, p ≤ 0.001-0.004), as did EA for all positions except for the two-legged stance on a soft surface (rs = 0.392-0.581, p ≤ 0.001-0.016). A total of 92% of participants stated that the instructions for the testing procedure were very well-explained, while 78% of participants enjoyed the balance testing, and 61% of participants could not decide whether the testing was easy or hard to perform. Conclusions: Instrumented posturography may complement clinical assessment in investigating postural control in children and adolescents. While the BESS score only allows for the consideration of a total score approximating postural control, instrumented posturography offers several parameters representing the responsiveness and magnitude of body sway as well as a more differentiated analysis of movement trajectory. Concise instrumented posturography protocols should be developed to augment neuropediatric assessments in cases where a deficiency in postural control is suspected, potentially stemming from disruptions in the processing of visual, proprioceptive, and/or vestibular information.

Use of Reactive Balance Assessments With Clinical Baseline Concussion Assessments in Collegiate Athletes

CONTEXT

Current clinical concussion evaluations assess balance deficits using static or dynamic balance tasks while largely ignoring reactive balance. Including a reactive balance assessment might provide a more comprehensive concussion evaluation.

OBJECTIVES

To identify redundancy in current clinical baseline assessments of concussion and determine whether reactive balance adds unique information to these evaluations.

DESIGN

Cross-sectional study.

SETTING

Clinical assessment.

PATIENTS OR OTHER PARTICIPANTS

A total of 279 healthy National Collegiate Athletic Association Division I athletes.

INTERVENTION(S)

Two cohorts of data were collected at the beginning of the athletic season. For cohort 1 (n = 191), the Immediate Post-Concussion Assessment and Cognitive Tool, instrumented modified push and release (I-mP&R), and Balance Error Scoring System (BESS) were administered. For cohort 2 (n = 88), the I-mP&R, BESS, timed tandem gait, walking with eyes closed, and clinical reaction time were administered.

MAIN OUTCOME MEASURE(S)

The strengths of the relationships between the Immediate Post-Concussion Assessment and Cognitive Tool cognitive indices, mP&R clinical score, instrumented measures (BESS sway; I-mP&R time to stability, latency, and step length), BESS score, timed tandem gait, walking time to completion, and clinical reaction time were characterized.

RESULTS

The strongest interinstrument correlation value was between single-task time to stability from the I-mP&R and clinical reaction time but was considered weak (r = 0.35, P = .001). The mP&R and I-mP&R clinical scores were weakly associated with the other assessments.

CONCLUSIONS

Weak correlations between interassessment variables indicated that little redundancy was present in the current clinical evaluations. Furthermore, reactive balance represents a unique domain of function that may improve the comprehensiveness of clinical assessments.

Symptoms and Central Sensory Integration in People With Chronic mTBI: Clinical Implications

INTRODUCTION

Balance deficits in people with chronic mild traumatic brain injury (mTBI; ≥3 months post-mTBI), thought to relate to central sensory integration deficits, are subtle and often difficult to detect. The purpose of this study was to determine the sensitivity of the instrumented modified clinical test of sensory integration for balance (mCTSIB) in identifying such balance deficits in people with symptomatic, chronic mTBI and to establish the associations between balance and mTBI symptom scores in the chronic mTBI group.

METHODS

The Institutional Review Board approved these study methods. Forty-one people with chronic mTBI and balance complaints and 53 healthy controls performed the mCTSIB (eyes open/closed on firm/foam surfaces; EoFi, EcFi, EoFo, and EcFo) with a wearable sensor on their waist to quantify sway area (m2/s4). Sensory reweighting variables were calculated for the firm and foam stance conditions. A stopwatch provided the clinical outcome for the mCTSIB (time). Each participant completed the Neurobehavioral Symptom Inventory (NSI), which quantifies mTBI-related symptoms and provides a total score, as well as sub-scores on affective, cognitive, somatic, and vestibular domains.

RESULTS

The mTBI group reported significantly higher symptom scores across each NSI sub-score (all Ps < .001). The mTBI group had a significantly larger sway area than the control group across all mCTSIB conditions and the mTBI group had significantly higher sensory reweighting scores compared to the control group on both the firm (P = .01) and foam (P = .04) surfaces. Within the mTBI group, the NSI vestibular score significantly related to the mCTSIB sway area EcFi (r = 0.38; P = .02), sway area EcFo (r = 0.43; P = .006), sensory reweighting firm (r = 0.33; P = .04), and sensory reweighting foam (r = 0.38; P = .02). The average sway area across the 4 mCTSIB conditions was significantly (area under the curve: 0.77; P < .001) better at differentiating groups than the mCTSIB clinical total score. The average sway area across the 4 mCTSIB conditions had a sensitivity of 73% and a specificity of 71%. The clinical mCTSIB outcome scores were not different between groups.

CONCLUSION

People with chronic mTBI appear to have central sensory integration deficits detectable by instrumented measures of postural assessment. These findings suggest that central sensory integration should be targeted in rehabilitation for people with chronic mTBI.

Validity and Reliability of Methods to Assess Movement Deficiencies Following Concussion: A COSMIN Systematic Review

BACKGROUND

There is an increased risk of subsequent concussion and musculoskeletal injury upon return to play following a sports-related concussion. Whilst there are numerous assessments available for clinicians for diagnosis and during return to play following concussion, many may lack the ability to detect these subclinical changes in function. Currently, there is no consensus or collated sources on the reliability, validity and feasibility of these assessments, which makes it difficult for clinicians and practitioners to select the most appropriate assessment for their needs.

OBJECTIVES

This systematic review aims to (1) consolidate the reliability and validity of motor function assessments across the time course of concussion management and (2) summarise their feasibility for clinicians and other end-users.

METHODS

A systematic search of five databases was conducted. Eligible studies were: (1) original research; (2) full-text English language; (3) peer-reviewed with level III evidence or higher; (4) assessed the validity of lower-limb motor assessments used to diagnose or determine readiness for athletes or military personnel who had sustained a concussion or; (5) assessed the test-retest reliability of lower-limb motor assessments used for concussion management amongst healthy athletes. Acceptable lower-limb motor assessments were dichotomised into instrumented and non-instrumented and then classified into static (stable around a fixed point), dynamic (movement around a fixed point), gait, and other categories. Each study was assessed using the COSMIN checklist to establish methodological and measurement quality.

RESULTS

A total of 1270 records were identified, with 637 duplicates removed. Titles and abstracts of 633 records were analysed, with 158 being retained for full-text review. A total of 67 records were included in this review; 37 records assessed reliability, and 35 records assessed the validity of lower-limb motor assessments. There were 42 different assessments included in the review, with 43% being non-instrumented, subjective assessments. Consistent evidence supported the use of instrumented assessments over non-instrumented, with gait-based assessments demonstrating sufficient reliability and validity compared to static or dynamic assessments.

CONCLUSION

These findings suggest that instrumented, gait-based assessments should be prioritised over static or dynamic balance assessments. The use of laboratory equipment (i.e. 3D motion capture, pressure sensitive walkways) on average exhibited sufficient reliability and validity, yet demonstrate poor feasibility. Further high-quality studies evaluating the reliability and validity of more readily available devices (i.e. inertial measurement units) are needed to fill the gap in current concussion management protocols. Practitioners can use this resource to understand the accuracy and precision of the assessments they have at their disposal to make informed decisions regarding the management of concussion.

TRAIL REGISTRATION

This systematic review was registered on PROSPERO (reg no. CRD42021256298).

An Evaluation of the Emerging Techniques in Sports-Related Concussion

SUMMARY

Sports-related concussion is now in public awareness more than ever before. Investigations into underlying pathophysiology and methods of assessment have correspondingly increased at an exponential rate. In this review, we aim to highlight some of the evidence supporting emerging techniques in the fields of neurophysiology, neuroimaging, vestibular, oculomotor, autonomics, head sensor, and accelerometer technology in the setting of the current standard: clinical diagnosis and management. In summary, the evidence we reviewed suggests that (1) head impact sensors and accelerometers may detect possible concussions that would not otherwise receive evaluation; (2) clinical diagnosis may be aided by sideline vestibular, oculomotor, and portable EEG techniques; (3) clinical decisions on return-to-play eligibility are currently not sensitive at capturing the neurometabolic, cerebrovascular, neurophysiologic, and microstructural changes that biomarkers have consistently detected days and weeks after clinical clearance. Such biomarkers include heart rate variability, quantitative electroencephalography, as well as functional, metabolic, and microstructural neuroimaging. The current challenge is overcoming the lack of consistency and replicability of any one particular technique to reach consensus.

Inertial Sensor-Based Assessment of Static Balance in Athletes with Chronic Ankle Instability

The Balance Error Scoring System (BESS), a subjective examiner-based assessment, is often employed to assess postural balance in individuals with chronic ankle instability (CAI); however, inertial sensors may enhance the detection of balance deficits. This study aimed to compare the BESS results between the CAI and healthy groups using conventional BESS scores and inertial sensor data. The BESS test (six conditions: double-leg, single-leg, and tandem stances on firm and foam surfaces, respectively) was performed for the CAI (n = 16) and healthy control (n = 16) groups with inertial sensors mounted on the sacrum and anterior shank. The BESS score was calculated visually by the examiner by counting postural sway as an error based on the recorded video. The root mean square for resultant acceleration (RMS_acc) in the anteroposterior, mediolateral, and vertical directions was calculated from each inertial sensor affixed to the sacral and shank surfaces during the BESS test. The mixed-effects analysis of variance and unpaired t-test were used to assess the effects of group and condition on the BESS scores and RMS_acc. No significant between-group differences were found in the RMS_acc of the sacral and shank surfaces, and the BESS scores (P > 0.05), except for the total BESS score in the foam condition (CAI: 14.4 ± 3.7, control: 11.7 ± 3.4; P = 0.039). Significant main effects of the conditions were found with respect to the BESS scores and RMS_acc for the sacral and anterior shank (P < 0.05). The BESS test with inertial sensors can detect differences in the BESS conditions for athletes with CAI. However, our method could not detect any differences between the CAI and healthy groups.

Systematic review of candidate prognostic factors for falling in older adults identified from motion analysis of challenging walking tasks

The objective of this systematic review is to identify motion analysis parameters measured during challenging walking tasks which can predict fall risk in the older population. Numerous studies have attempted to predict fall risk from the motion analysis of standing balance or steady walking. However, most falls do not occur during steady gait but occur due to challenging centre of mass displacements or environmental hazards resulting in slipping, tripping or falls on stairs. We conducted a systematic review of motion analysis parameters during stair climbing, perturbed walking and obstacle crossing, predictive of fall risk in healthy older adults. We searched the databases of Pubmed, Scopus and IEEEexplore.A total of 78 articles were included, of which 62 simply compared a group of younger to a group of older adults. Importantly, the differences found between younger and older adults did not match those found between older adults at higher and lower risk of falls. Two prospective and six retrospective fall history studies were included. The other eight studies compared two groups of older adults with higher or lower risk based on mental or physical performance, functional decline, unsteadiness complaints or task performance. A wide range of parameters were reported, including outcomes related to success, timing, foot and step, centre of mass, force plates, dynamic stability, joints and segments. Due to the large variety in parameter assessment methods, a meta-analysis was not possible. Despite the range of parameters assessed, only a few candidate prognostic factors could be identified: older adults with a retrospective fall history demonstrated a significant larger step length variability, larger step time variability, and prolonged anticipatory postural adjustments in obstacle crossing compared to older adults without a fall history. Older adults who fell during a tripping perturbation had a larger angular momentum than those who did not fall. Lastly, in an obstacle course, reduced gait flexibility (i.e., change in stepping pattern relative to unobstructed walking) was a prognostic factor for falling in daily life. We provided recommendations for future fall risk assessment in terms of study design.In conclusion, studies comparing older to younger adults cannot be used to explore relationships between fall risk and motion analysis parameters. Even when comparing two older adult populations, it is necessary to measure fall history to identify fall risk prognostic factors.

Assessment of Physical Tests in 6-11 Years Old Children: Findings from the Play Lifestyle and Activity in Youth (PLAY) Study

The purpose was to evaluate selected physical tests in children and to compare the outcomes by sex. A cross-sectional study design was used to evaluate children 6-11 years who completed five physical tests: hand grip, vertical jump, sit and reach, Y-balance, and obstacle course (time and score). The outcome measures including test results were descriptively examined and compared by sex. The study participants consisted of 133 children (62 males and 71 females, with a median age of 7.8 years). Girls showed superior sit and reach performance (p = 0.002) compared with boys. Boys demonstrated better Y-balance scores (p = 0.007) and faster obstacle time (p = 0.042) than girls. Sex comparison within three age groups (6-<8 years, 8-<10 years, and 10-<12 years) showed that girls performed better on the sit and reach compared with boys in the in 6-<8 years (p = 0.009). Boys demonstrated higher Y-balance scores (p = 0.017) and faster obstacle time (p = 0.007) compared with girls in the 8-<10-year age group. These data will serve to guide future efforts to evaluate normative measures of physical literacy and guide targeted training interventions to promote sustained physical activity in children with deficits relative to their age and sex norms.

Is the Sport Concussion Assessment Tool 5th Edition a useful concussion assessment tool in head‐injured patients presenting to the emergency department?

OBJECTIVE

Concussion is a common ED complaint, but diagnosis is challenging as there are no validated objective measures. Use of concussion tools derived from sports medicine is common, but these tools are not well validated in ED settings. The aim of this study was to assess the ability of the Sport Concussion Assessment Tool 5th Edition (SCAT5) to identify concussion in ED patients presenting following head injury.

METHODS

We conducted a prospective observational study of head-injured adult patients presenting to ED between March and July 2021. ED diagnosis of concussion was used as the diagnostic standard, and we assessed the diagnostic performance of the SCAT5 test and its three subsections (Standardised Assessment of Concussion (SAC), Post-Concussion Symptom Scale (PCSS) and Modified Balance Error Scoring System (mBESS)) against this.

RESULTS

Thirty-two head-injured participants were enrolled, 19 of whom had a discharge diagnosis of concussion, alongside 17 controls. Median time for SCAT5 testing was 21 (interquartile range 16-27) min. Fifteen (30.6%) participants were interrupted during testing. Area under the curve (AUC) (95% confidence interval) for the SAC, PCSS and mBESS were 0.51 (0.34-0.68), 0.92 (0.84-0.99) and 0.66 (0.47-0.85), respectively. Sensitivity and specificity of sections were as follows: entire SCAT5 (100.0%, 20.0%), SAC (48.1%, 60.0%), PCSS (89.7%, 85.0%) and mBESS (83.3%, 58.8%). Using PCSS alone would have identified 17 of 19 concussions.

CONCLUSION

The SCAT5 test had a low specificity, was long and was frequently interrupted. We suggest it is not an ideal assessment to use in ED. The PCSS score performed well and was easy to complete. It may be useful as a standalone tool to simplify ED concussion identification.

Concussion increases within-player injury risk in male professional rugby union

OBJECTIVES

To assess within-player change in injury risk and between-player subsequent injury risk associated with concussive and common non-concussive injuries in professional rugby union.

METHODS

This prospective cohort study in Welsh professional male rugby union analysed within-player and between-player injury risk for five common injuries: concussion, thigh haematoma, hamstring muscle strain, lateral ankle sprain and acromioclavicular joint sprain. Survival models quantified within-player injury risk by comparing precommon (before) injury risk to postcommon (after) injury risk, whereas between-player subsequent injury risk was quantified by comparing players who had sustained one of the common injuries against those who had not sustained the common injury. HRs and 95% CIs were calculated. Specific body area and tissue type were also determined for new injuries.

RESULTS

Concussion increased the within-player overall injury risk (HR 1.26 (95% CI 1.11 to 1.42)), elevating head/neck (HR 1.47 (95% CI 1.18 to 1.83)), pelvic region (HR 2.32 (95% CI 1.18 to 4.54)) and neurological (HR 1.38 (95% CI 1.08 to 1.76)) injury risk. Lateral ankle sprains decreased within-player injury risk (HR 0.77 (95% CI 0.62 to 0.97)), reducing head/neck (HR 0.60 (95% CI 0.39 to 0.91)), upper leg and knee (HR 0.56 (95% CI 0.39 to 0.81)), joint and ligament (HR 0.72 (95% CI 0.52 to 0.99)) and neurological (HR 0.55 (95% CI 0.34 to 0.91)) injury risk. Concussion (HR 1.24 (95% CI 1.10 to 1.40)), thigh haematomas (HR 1.18 (95% CI 1.04 to 1.34)) and hamstring muscle strains (HR 1.14 (95% CI 1.01 to 1.29)) increased between-player subsequent injury risk.

CONCLUSION

Elevated within-player injury risk was only evident following concussive injuries, while lateral ankle sprains reduced the risk. Both concussion and ankle injuries altered head/neck and neurological injury risk, but in opposing directions. Understanding why management of ankle sprains might be effective, while current concussion management is not at reducing such risks may help inform concussion return to play protocols.

Do sensorimotor control properties mediate sway in people with chronic balance complaints following mTBI?

BACKGROUND

Up to 40% of mild traumatic brain injuries (mTBI) can result in chronic unresolved symptoms, such as balance impairment, that persist beyond three months. Sensorimotor control, the collective coordination and regulation of both sensory and motor components of the postural control system, may underlie balance deficits in chronic mTBI. The aim of this study was to determine if the relationship between severity of impairment in chronic (> 3 months) mTBI and poorer balance performance was mediated by sensorimotor integration measures.

METHODS

Data were collected from 61 healthy controls and 58 mTBI participants suffering persistent balance problems. Participants completed questionnaires (Dizziness Handicap Inventory (DHI), Neurobehavioral Symptom Inventory (NSI), and Sports Concussion Assessment Tool Symptom Questionnaire (SCAT2)) and performed instrumented postural sway assessments and a test of Central Sensory Motor Integration (CSMI). Exploratory Factor Analysis was used to reduce the variables used within the mediation models to constructs of impairment (Impairment Severity - based on questionnaires), balance (Sway Dispersion - based on instrumented postural sway measures), and sensorimotor control (Sensory Weighting, Motor Activation and Time Delay - based on parameters from CSMI tests). Mediation analyses used path analysis to estimate the direct effect (between impairment and balance) and indirect (mediating) effects (from sensorimotor control).

RESULTS

Two out of three sensorimotor integration factors (Motor Activation and Time Delay) mediated the relationship between Impairment Severity and Sway Dispersion, however, there was no mediating effect of Sensory Weighting.

SIGNIFICANCE

These findings have clinical implications since rehabilitation of balance commonly focuses on sensory cues. Our findings indicate the importance of Motor Activation and Time Delay, and thus a focus on strategies to improve factors related to these constructs throughout the rehabilitative process (i.e., level of muscular contractions to control joint torques; response time to stimuli/perturbations) may improve a patient's balance control.

Towards defining biomarkers to evaluate concussions using virtual reality and a moving platform (BioVRSea)

Current diagnosis of concussion relies on self-reported symptoms and medical records rather than objective biomarkers. This work uses a novel measurement setup called BioVRSea to quantify concussion status. The paradigm is based on brain and muscle signals (EEG, EMG), heart rate and center of pressure (CoP) measurements during a postural control task triggered by a moving platform and a virtual reality environment. Measurements were performed on 54 professional athletes who self-reported their history of concussion or non-concussion. Both groups completed a concussion symptom scale (SCAT5) before the measurement. We analyzed biosignals and CoP parameters before and after the platform movements, to compare the net response of individual postural control. The results showed that BioVRSea discriminated between the concussion and non-concussion groups. Particularly, EEG power spectral density in delta and theta bands showed significant changes in the concussion group and right soleus median frequency from the EMG signal differentiated concussed individuals with balance problems from the other groups. Anterior–posterior CoP frequency-based parameters discriminated concussed individuals with balance problems. Finally, we used machine learning to classify concussion and non-concussion, demonstrating that combining SCAT5 and BioVRSea parameters gives an accuracy up to 95.5%. This study is a step towards quantitative assessment of concussion.

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.

The Relationship Between Measures of Postural Control in Concussion Assessment

OBJECTIVE

To determine the relationship between postural sway performance during commonly utilized postural control assessments following a concussion, including the modified Balance Error Scoring System (mBESS), concussion balance test (COBALT), and sensory organization test (SOT) in healthy young adults.

APPROACH

Twenty participants completed all balance testing. The mBESS conditions included double limb stance, single limb stance, and tandem stance. The COBALT was comprised of yaw plane head shake (HS) and vestibular ocular reflex cancellation conditions performed on firm and foam surfaces. Subjects performed 6 conditions of the SOT (C1-C6), which systematically perturbed sensory inputs. Postural sway performance was measured using a single force plate and quantified as a sway score for the mBESS and COBALT, and an equilibrium score for the SOT. Spearman rank correlations were used to examine the relationship between postural sway performance for each test.

MAIN RESULTS

There was a moderate positive correlation between mBESS-tandem stance and the HS on foam COBALT condition (r = .643, P = .002). There was a moderate negative correlation between mBESS-double limb stance and SOT-C6 (r = -.512, P = .021), and between mBESS-single limb stance and SOT-C6 (r = -.523, P = .018). The COBALT and SOT demonstrated numerous moderate to good negative correlations (r = -.448 to -.708, P ≤ .05), including a good negative correlation between HS on foam and SOT-C1 (r = -.725, P = .0003).

SIGNIFICANCE

Performance on the mBESS had minimal relationship to performance on the COBALT and SOT, suggesting that the clinical standard may not challenge sensory integration at the same capacity as other tests. All COBALT conditions had fair to good associations to at least 2 SOT conditions, suggesting both assessments are representative of sensory integration. Further investigation of the current clinical approach is warranted as the COBALT may be a clinically feasible test of sensory integration.

Comparison of Concurrent and Same-Day Balance Measurement Approaches in a Large Sample of Uninjured Collegiate Athletes

BACKGROUND

Measures of postural stability are useful in assisting the diagnosing and managing of athlete concussion. Error counting using the Balance Error Scoring System (BESS) is the clinical standard, but has notable limitations. New technologies offer the potential to increase precision and optimize testing protocols; however, whether these devices enhance clinical assessment remains unclear.

PURPOSE

To examine the relationships between metrics of balance performance using different measurement systems in uninjured, healthy collegiate athletes.

STUDY DESIGN

Cross-sectional.

METHODS

Five hundred and thirty uninjured collegiate athletes were tested using the C3Logix app, which computes ellipsoid volume as a measure of postural stability during the six standard BESS conditions, while concurrently, errors were manually counted during each condition per standard BESS protocols. The association between concurrently measured ellipsoid volumes and error counts were examined with Spearman's correlations. From this sample, 177 participants also performed two double-leg conditions on the Biodex BioSway force plate system on the same day. This system computes Sway Index as a measure of postural stability. The association of ellipsoid volume (C3Logix) and Sway Index (Biodex) was examined with Spearman's correlations. Individual-level data were plotted to visually depict the relationships.

RESULTS

C3Logix ellipsoid volume and concurrently recorded error counts were significantly correlated in five of the six BESS conditions (rs:.22-.62; p< 0.0001). C3Logix ellipsoid volume and Biodex Sway Index were significantly correlated in both conditions (rs=.22-.27, p< 0.004). However, substantial variability was shown in postural stability across all three measurement approaches.

CONCLUSION

Modest correlation coefficients between simultaneous and same-day balance assessments in uninjured collegiate athletes suggest a need to further optimize clinical protocols for concussion diagnosis.

LEVEL OF EVIDENCE

2b.

Modulating Cognitive–Motor Multitasking with Commercial-off-the-Shelf Non-Invasive Brain Stimulation

One growing area of multitasking research involves a focus on performing cognitive and motor tasks in tandem. In these situations, increasing either cognitive or motor demands has implications for performance in both tasks, an effect which is thought to be due to competing neural resources. Separate research suggests that non-invasive brain stimulation may offer a means to mitigate performance decrements experienced during multitasking. In the present study, we investigated the degree to which a commercially available non-invasive brain stimulation device (Halo Sport) alters balance performance in the presence of different types of cognitive demands. Specifically, we tested if performing a secondary cognitive task impacts postural sway in healthy young adults and if we could mitigate this impact using transcranial direct current stimulation (tDCS) applied over the primary motor cortex. Furthermore, we included conditions of unstable and stable surfaces and found that lower surface stability increased postural sway. In addition, we found that cognitive load impacted postural sway but in the opposite pattern we had anticipated, with higher sway found in the single-task control condition compared to executive function conditions. Finally, we found a small but significant effect of tDCS on balance with decreased sway for active (compared to sham) tDCS.

The Specificity of Cognitive-Motor Dual-Task Interference on Balance in Young and Older Adults

Standing upright on stable and unstable surfaces requires postural control. Postural control declines as humans age, presenting greater risk of fall-related injury and other negative health outcomes. Secondary cognitive tasks can further impact balance, which highlights the importance of coordination between cognitive and motor processes. Past research indicates that this coordination relies on executive function (EF; the ability to control, maintain, and flexibly direct attention to achieve goals), which coincidentally declines as humans age. This suggests that secondary cognitive tasks requiring EF may exert a greater influence on balance compared to non-EF secondary tasks, and this interaction could be exaggerated among older adults. In the current study, we had younger and older adults complete two Surface Stability conditions (standing upright on stable vs. unstable surfaces) under varying Cognitive Load; participants completed EF (Shifting, Inhibiting, Updating) and non-EF (Processing Speed) secondary cognitive tasks on tablets, as well as a single task control scenario with no secondary cognitive task. Our primary balance measure of interest was sway area, which was measured with an array of wearable inertial measurement unit sensors. Replicating prior work, we found a main effect of Surface Stability with less sway on stable surfaces compared to unstable surfaces, and we found an interaction between Age and Surface Stability with older adults exhibiting significantly greater sway selectively on unstable surfaces compared to younger adults. New findings revealed a main effect of Cognitive Load on sway, with the single task condition having significantly less sway than two of the EF conditions (Updating and Shifting) and the non-EF condition (Processing Speed). We also found an interaction of Cognitive Load and Surface Stability on postural control, where Surface Stability impacted sway the most for the single task and two of the executive function conditions (Inhibition and Shifting). Interestingly, Age did not interact with Cognitive Load, suggesting that both age groups were equally impacted by secondary cognitive tasks, regardless the presence or type of secondary cognitive task. Taken together, these patterns suggest that cognitive demands vary in their impact on posture control across stable vs. unstable surfaces, and that EF involvement may not be the driving mechanism explaining cognitive-motor dual-task interference on balance.

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.

Phybrata Sensors and Machine Learning for Enhanced Neurophysiological Diagnosis and Treatment

Concussion injuries remain a significant public health challenge. A significant unmet clinical need remains for tools that allow related physiological impairments and longer-term health risks to be identified earlier, better quantified, and more easily monitored over time. We address this challenge by combining a head-mounted wearable inertial motion unit (IMU)-based physiological vibration acceleration (“phybrata”) sensor and several candidate machine learning (ML) models. The performance of this solution is assessed for both binary classification of concussion patients and multiclass predictions of specific concussion-related neurophysiological impairments. Results are compared with previously reported approaches to ML-based concussion diagnostics. Using phybrata data from a previously reported concussion study population, four different machine learning models (Support Vector Machine, Random Forest Classifier, Extreme Gradient Boost, and Convolutional Neural Network) are first investigated for binary classification of the test population as healthy vs. concussion (Use Case 1). Results are compared for two different data preprocessing pipelines, Time-Series Averaging (TSA) and Non-Time-Series Feature Extraction (NTS). Next, the three best-performing NTS models are compared in terms of their multiclass prediction performance for specific concussion-related impairments: vestibular, neurological, both (Use Case 2). For Use Case 1, the NTS model approach outperformed the TSA approach, with the two best algorithms achieving an F1 score of 0.94. For Use Case 2, the NTS Random Forest model achieved the best performance in the testing set, with an F1 score of 0.90, and identified a wider range of relevant phybrata signal features that contributed to impairment classification compared with manual feature inspection and statistical data analysis. The overall classification performance achieved in the present work exceeds previously reported approaches to ML-based concussion diagnostics using other data sources and ML models. This study also demonstrates the first combination of a wearable IMU-based sensor and ML model that enables both binary classification of concussion patients and multiclass predictions of specific concussion-related neurophysiological impairments.

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.

Utility of a Postural Stability/Perceptual Inhibition Dual Task for Identifying Concussion in Adolescents

CONTEXT

Research in the area of dual-task paradigms to assess sport-related concussion (SRC) status is growing, but additional assessment of this paradigm in adolescents is warranted.

DESIGN

This case-control study compared 49 adolescent athletes aged 12-20 years with diagnosed SRC to 49 age- and sex-matched controls on visual-spatial discrimination and perceptual inhibition (PIT) reaction time tasks performed while balancing on floor/foam pad conditions.

METHODS

The SRC group completed measures at a single time point between 1 and 10 days postinjury. Primary outcomes were dual-task reaction time, accuracy, and sway. General linear models evaluated differences between groups (P < .05). Logistic regression identified predictors of concussion from outcomes. Area under the curve evaluated discriminative ability of identifying SRC.

RESULTS

Results supported significantly higher anterior-posterior (AP) sway values in concussed participants for visual-spatial discrimination and PIT when balancing on the floor (P = .03) and foam pad (P = .03), as well as mediolateral sway values on the floor during visual-spatial discrimination (P = .01). Logistic regression analysis (R2 = .15; P = .001) of all dual-task outcomes identified AP postural sway during the PIT foam dual task as the only significant predictor of concussed status (ß = -2.4; P = .004). Total symptoms (area under the curve = 0.87; P < .001) and AP postural sway on foam (area under the curve = 0.70; P = .001) differentiated concussed from controls.

CONCLUSION

The AP postural sway on foam during a postural stability/PIT dual task can identify concussion in adolescents between 1 and 10 days from injury.

Balance effort, Cone of Economy, and dynamic compensatory mechanisms in common degenerative spinal pathologies

BACKGROUND

Changes in balance are common in individuals with spinal disorders and may cause falls. Balance efficiency, is the ability of a person to maintain their center of gravity with minimal neuromuscular energy expenditure, oftentimes referred to as Cone of Economy (CoE). CoE balance is defined by two sets of measures taken from the center of mass (CoM) and head: 1) the range-of-sway (RoS) in the coronal and sagittal planes, and 2) the overall sway distance. This allows spine caregivers to assess the severity of a patient's balance, balance pattern, and dynamic posture and record the changes following surgical intervention. Maintenance of balance requires coordination between the central nervous and musculoskeletal systems.

RESEARCH QUESTION

To discern differences in balance effort values between common degenerative spinal pathologies and a healthy control group.

METHODS

Three-hundred and forty patients with degenerative spinal pathologies: cervical spondylotic myelopathy (CSM), adult degenerative scoliosis (ADS), sacroiliac dysfunction (SIJD), degenerative lumbar spondylolisthesis (DLS), single-level lumbar degeneration (LD), and failed back syndrome (FBS), and 40 healthy controls were recruited. A functional balance test was performed approximately one week before surgery recorded by 3D video motion capture.

RESULTS

Balance effort and compensatory mechanisms were found to be significantly greater in degenerative spinal pathologies patients compared to controls. Head and Center of Mass (CoM) overall sway ranged from 65.22 to 92.78 cm (p < 0.004) and 35.77-53.31 cm (p < 0.001), respectively in degenerative spinal pathologies patients and in comparison to controls (Head: 44.52 cm, CoM: 22.24 cm). Patients with degenerative spinal pathologies presented with greater trunk (1.61-2.98°, p < 0.038), hip (4.25-5.87°, p < 0.049), and knee (4.55-6.09°, p < 0.036) excursion when compared to controls (trunk: 0.95°, hip: 2.97°, and knee: 2.43°).

SIGNIFICANCE

The results of this study indicate that patients from a wide variety of degenerative spinal pathologies similarly exhibit markedly diminished balance (and compensatory mechanisms) as indicated by increased sway on a Romberg test and a larger Cone of Economy (CoE) as compared to healthy controls. Balance effort, as measured by overall sway, was found to be approximately double in patients with degenerative spinal pathologies compared to healthy matched controls. Clinicians can compare CoE parameters among symptomatic patients from the different cohorts using the Haddas' CoE classification system to guide their postoperative prognosis.

Vestibular, Oculomotor, and Balance Functions in Children With and Without Concussion

OBJECTIVE

The main objective of this study was to assess whether objective vestibular, oculomotor, and balance functions were impaired in children with a current diagnosis of concussion with vestibular and/or ocular symptoms.

SETTING

Data were collected in a vestibular/ocular clinical laboratory. Patient participants were recruited from a concussion clinic in a children's hospital.

PARTICIPANTS

Thirty-three children aged 8 to 17 years with a current diagnosis of concussion and vestibular and/or ocular symptoms and 30 children without concussion.

DESIGN

Cross-sectional single-visit study.

MAIN OUTCOME MEASURES

Eye-tracking rotary chair oculomotor and vestibular measures, vestibular evoked potentials, and static posturography.

RESULTS

There were no statistically significant differences on any clinical measure between children with concussion and children without concussion. Younger children without concussion performed significantly worse on several rotary chair and balance measures compared with older children without concussion.

CONCLUSIONS

No vestibular, oculomotor, or balance measures were significantly different between children with concussion and children without concussion, suggesting these measures may not be useful in the evaluation of a child with concussion and vestibular and/or oculomotor symptoms. Future research should investigate age effects and other vestibular and oculomotor tests to identify objective findings that better relate to vestibular and/or ocular symptoms in children with concussion.

Internal Consistency of Sway Measures via Embedded Head-Mounted Accelerometers: Implications for Neuromotor Investigations

Accelerometers are being increasingly incorporated into neuroimaging devices to enable real-time filtering of movement artifacts. In this study, we evaluate the reliability of sway metrics derived from these accelerometers in a standard eyes-open balance assessment to determine their utility in multimodal study designs. Ten participants equipped with a head-mounted accelerometer performed an eyes-open standing condition on 7 consecutive days. Sway performance was quantified with 4 standard metrics: root-mean-square (RMS) acceleration, peak-to-peak (P2P) acceleration, jerk, and ellipse area. Intraclass correlation coefficients (ICC) quantified reliability. P2P in both the mediolateral (ICC = 0.65) and anteroposterior (ICC = 0.67) planes yielded the poorest reliability. Both ellipse area and RMS exhibited good reliability, ranging from 0.76 to 0.84 depending on the plane. Finally, jerk displayed the highest reliability with an ICC value of 0.95. Moderate to excellent reliability was observed in all sway metrics. These findings demonstrate that head-mounted accelerometers, commonly found in neuroimaging devices, can be used to reliably assess sway. These data validate the use of head-mounted accelerometers in the assessment of motor control alongside other measures of brain activity such as electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS).

Anxiety does not always affect balance: the predominating role of cognitive engagement in a video gaming task

Scientists have predominantly assessed anxiety's impact on postural control when anxiety is created by the need to maintain balance (e.g., standing at heights). In the present study, we investigate how postural control and its mechanisms (i.e., vestibular function) are impacted when anxiety is induced by an unrelated task (playing a video game). Additionally, we compare watching and playing a game to dissociate postural adaptations caused by increased engagement rather than anxiety. Participants [N = 25, female = 8, M (SD) age = 23.5 (3.9)] held a controller in four standing conditions of varying surface compliance (firm or foam) and with or without peripheral visual occlusion across four blocks: quiet standing (baseline), watching the game with a visual task (watching), playing the game (low anxiety), and playing under anxiety (high anxiety). We measured sway area, sway frequency, root mean square (RMS) sway, anxiety, and mental effort. Limited sway differences emerged between anxiety blocks (only sway area on firm surface). The watching block elicited more sway than baseline (greater sway area and RMS sway; lower sway frequency), and the low anxiety block elicited more sway than the watching block (greater sway area and RMS sway; higher sway frequency). Mental effort was associated with increased sway area and RMS sway. Our findings indicate that anxiety, when generated through competition, has minimal impact on postural control. Postural control primarily adapts according to mental effort and more cognitively engaging task constraints (i.e., playing versus watching). We speculate increased sway reflects the prioritization of attention to game performance over postural control.

Examining Whether Onfield Motor Incoordination Is Associated With Worse Performance on the SCAT5 and Slower Clinical Recovery Following Concussion

Objective: To examine the relationship between video-identified onfield motor incoordination, the acute assessment of concussion, and recovery time during three seasons of National Rugby League (NRL) play.

Methods: Blows to the head (“head impact events”) were recorded by sideline video operators and medical staff. Any player with a suspected concussion underwent a Head Injury Assessment in which he was taken off the field and medically evaluated, including the administration of the Sports Concussion Assessment Tool, 5th Edition (SCAT5). Video footage was later examined to determine the presence or absence of onfield motor incoordination following the head impact event.

Results: Motor incoordination was identified in 100/1,706 head impact events (5.9%); 65 of the 100 instances of motor incoordination (65.0%) were ultimately medically diagnosed with a concussion. In 646 athletes for whom SCAT5 data were available, those with motor incoordination were more likely to report both dizziness and balance problems than those without motor incoordination, but there were no group differences on an objective balance test. Additionally, there was no relationship between presence/absence of motor incoordination and number of games missed or time to medical clearance for match play.

Conclusion: In NRL players, motor incoordination is a readily observable onfield sign that is strongly associated with a medical diagnosis of concussion and with self-reported dizziness/balance problems. However, onfield motor incoordination is not associated with objective balance performance and it is not predictive of time to recover following concussion.

Technology and concussion: A scoping review

Background

Technology for concussion identification and management is rapidly expanding across the continuum of care. Although many technologies offer a range of services around concussion, there is an absence of a non-commercial online location for medical providers to access regarding the functionality of the various technologies used in concussion identification and management.

Objective

The purpose of this review is to present research findings on technology for concussion identification and management.

Methods

Searches for eligible studies were conducted using the PubMed, EMBASE, and Scopus databases with specific search criteria. Through a stepwise process, full-text articles were selected for inclusion if they described clinically useful electronic technologies (i.e. electronics able to be used in standard clinical environments including telehealth) by healthcare providers or end users (i.e. parents or athletes).

Results

A total of 29 articles were included in this review and described technology used to measure symptoms (3), neurocognitive performance (7), the visual system (4), and balance or dual task performance (18). Within the results, various technologies demonstrated increased utility for concussion identification, often detecting subtle deficits not possible with current low-tech clinical methods, differentiating those with concussion from those without concussion, with strong reliability and validity.

Conclusion

Innovative technologies included in this review demonstrate enhanced ability to identify and manage symptoms of concussion, neurocognitive deficits, visual deficits, and balance and dual-task deficits.

Objective Dual-Task Turning Measures for Return-to-Duty Assessment After Mild Traumatic Brain Injury: The ReTURN Study Protocol

Determining readiness for duty after mild traumatic brain injury (mTBI) is essential for the safety of service members and their unit. Currently, these decisions are primarily based on self-reported symptoms, objective measures that assess a single system, or standardized physical or cognitive tests that may be insensitive or lack ecological validity for warrior tasks. While significant technological advancements have been made in a variety of assessments of these individual systems, assessments of isolated tasks are neither diagnostically accurate nor representative of the demands imposed by daily life and military activities. Emerging evidence suggests that complex tasks, such as dual-task paradigms or turning, have utility in probing functional deficits after mTBI. Objective measures from turning tasks in single- or dual-task conditions, therefore, may be highly valuable for clinical assessments and return-to-duty decisions after mTBI. The goals of this study are to assess the diagnostic accuracy, predictive capacity, and responsiveness to rehabilitation of objective, dual-task turning measures within an mTBI population. These goals will be accomplished over two phases. Phase 1 will enroll civilians at three sites and active-duty service members at one site to examine the diagnostic accuracy and predictive capacity of dual-task turning outcomes. Phase 1 participants will complete a series of turning tasks while wearing inertial sensors and a battery of clinical questionnaires, neurocognitive testing, and standard clinical assessments of function. Phase 2 will enroll active-duty service members referred for rehabilitation from two military medical treatment facilities to investigate the responsiveness to rehabilitation of objective dual-task turning measures. Phase 2 participants will complete two assessments of turning while wearing inertial sensors: a baseline assessment prior to the first rehabilitation session and a post-rehabilitation assessment after the physical therapist determines the participant has completed his/her rehabilitation course. A variable selection procedure will then be implemented to determine the best task and outcome measure for return-to-duty decisions based on diagnostic accuracy, predictive capacity, and responsiveness to rehabilitation. Overall, the results of this study will provide guidance and potential new tools for clinical decisions in individuals with mTBI.

Clinical Trial Registration: clinicaltrials.gov, Identifier NCT03892291.

Noninvasive Continuous Monitoring of Vital Signs With Wearables: Fit for Medical Use?

BACKGROUND

Wearables (= wearable computer) enable continuous and noninvasive monitoring of a range of vital signs. Mobile and cost-effective devices, combined with powerful data analysis tools, open new dimensions in assessing body functions ("digital biomarkers").

METHODS

To answer the question whether wearables are ready for use in the medical context, a PubMed literature search and analysis for their clinical-scientific use using publications from the years 2008 to 2018 was performed.

RESULTS

A total of 79 out of 314 search hits were publications on clinical trials with wearables, of which 16 were randomized controlled trials. Motion sensors were most frequently used to measure defined movements, movement disorders, or general physical activity. Approximately 20% of the studies used sensors to detect cardiovascular parameters. As for the sensor location, the wrist was chosen in most studies (22.8%).

CONCLUSION

Wearables can be used in a precisely defined medical context, when taking into account complex influencing factors.

The use of inertial measurement units to assess gait and postural control following concussion

BACKGROUND

Impairments in gait and balance function are typical after concussion. There is evidence that these neuromuscular deficits persist past the typical time of symptom resolution. The ability to quantify these changes in gait and balance may provide useful information when making return to play decisions in clinical settings.

RESEARCH QUESTION

Are changes in gait function and postural control evident across the course of a concussion management program?

METHODS

A retrospective analysis of a convenience sample of 38 patients who were seen for concussion between October 2017 and May 2019 was performed. Gait and balance measures were assessed at their initial clinic visit post-injury and at their clearance visit using inertial measurement units. During dual-task walking trials, the medial-lateral motion of the center of mass and gait velocity were measured. Postural sway complexity and jerk index were measured during both eyes-open and eyes-closed balance trials.

RESULTS

Paired samples t-tests and Wilcoxon signed rank tests were used to determine whether statistically significant changes occurred for the gait and balance variables, respectively. Medial-lateral sway decreased (4.4 ± 1.3 cm to 4.0 ± 1.2 cm, p = 0.018) and gait velocity increased (0.78 ± 0.23 m/s to 0.91 ± 0.18 m/s, p <  0.001) from initial to clearance testing. Jerk index decreased (6.41 ± 11.06 m²/s⁵ to 5.73 ± 4.28 m²/s⁵, p = 0.031) and (11.87 ± 26.42 m²/s⁵ to 7.87 ± 8.38 m²/s⁵, p = 0.003) from initial to clearance testing for the eyes-open and eyes-closed conditions, respectively. Complexity index increased (2.38 ± 1.08-2.86 ± 0.72, p = 0.010) from initial to clearance testing for the eyes-closed condition. There was no change in complexity index for the eyes-open condition.

SIGNIFICANCE

These preliminary results support the potential use of measures of gait and postural control to assess recovery following a concussion in a clinical setting.

Physiological Vibration Acceleration (Phybrata) Sensor Assessment of Multi-System Physiological Impairments and Sensory Reweighting Following Concussion

Objective

To assess the utility of a head-mounted wearable inertial motion unit (IMU)-based physiological vibration acceleration (“phybrata”) sensor to support the clinical diagnosis of concussion, classify and quantify specific concussion-induced physiological system impairments and sensory reweighting, and track individual patient recovery trajectories.

Methods

Data were analyzed from 175 patients over a 12-month period at three clinical sites. Comprehensive clinical concussion assessments were first completed for all patients, followed by testing with the phybrata sensor. Phybrata time series data and spatial scatter plots, eyes open (Eo) and eyes closed (Ec) phybrata powers, average power (Eo+Ec)/2, Ec/Eo phybrata power ratio, time-resolved phybrata spectral density (TRPSD) distributions, and receiver operating characteristic (ROC) curves are compared for individuals with no objective impairments and those clinically diagnosed with concussions and accompanying vestibular impairment, other neurological impairment, or both vestibular and neurological impairments. Finally, pre- and post-injury phybrata case report results are presented for a participant who was diagnosed with a concussion and subsequently monitored during treatment, rehabilitation, and return-to-activity clearance.

Results

Phybrata data demonstrate distinct features and patterns for individuals with no discernable clinical impairments, diagnosed vestibular pathology, and diagnosed neurological pathology. ROC curves indicate that the average power (Eo+Ec)/2 may be utilized to support clinical diagnosis of concussion, while Eo and Ec/Eo may be utilized as independent measures to confirm accompanying neurological and vestibular impairments, respectively. All 3 measures demonstrate area under the curve (AUC), sensitivity, and specificity above 90% for their respective diagnoses. Phybrata spectral analyses demonstrate utility for quantifying the severity of concussion-induced physiological impairments, sensory reweighting, and subsequent monitoring of improvements throughout treatment and rehabilitation.

Conclusion

Phybrata testing assists with objective concussion diagnosis and provides an important adjunct to standard concussion assessment tools by objectively ascertaining neurological and vestibular impairments, guiding targeted rehabilitation strategies, monitoring recovery, and assisting with return-to-sport/work/learn decision-making.

Instrumented balance assessment in mild traumatic brain injury: Normative values and descriptive data for acute, sub-acute and chronic populations

Often the Balance Error Scoring System (BESS) is used to assess balance during a clinical evaluation of a patient presenting with mild Traumatic Brain Injury (mTBI). Although recent research has shown the benefits of using inertial sensor measures such as the Root Mean Square (RMS) of the acceleration in place of clinical scoring, few normative data are available for clinicians to reference. The purpose of this paper was to provide normative data collected using wearable sensors for healthy controls across three age groups, as well as providing cohort data for mTBI participants across three stages following injury (acute, sub-acute and chronic). The RMS in the Medio-Lateral direction (ML RMS sway) of each condition (double stance – DS; single stance – SS; and tandem stance – TS) was extracted per participant for analysis. The average ML RMS sway across all conditions was also calculated (ML RMS-Av). Percentiles were calculated to provide normative data, and two multivariate general linear models were used to evaluate differences between 1) non-athlete controls, athlete controls, and athletes with acute mTBI, and 2) non-athletic cohorts of control, sub-acute and chronic mTBI groups across young, middle-aged, and older adults. Model 1 revealed athletes with acute mTBI had more ML RMS sway than athlete controls the for the DS condition ( p < 0.001), but no differences with non-athlete controls. Athlete controls also had less ML RMS sway for the SS condition and ML RMS-Av ( p ≤ 0.022) compared with non-athlete controls. Model 2 revealed less ML RMS sway in the control group than the sub-acute and chronic mTBI groups for DS ( p ≤ 0.004), but no differences between the sub-acute and chronic group, while more ML RMS sway occurred in the chronic group compared with the control and sub-acute groups for the TS condition and ML RMS-Av ( p ≤ 0.013). Older adults had more ML RMS sway than young and middle-aged adults for SS, TS and ML RMS-Av ( p ≤ 0.019), while there were no differences between the young and middle-aged adults. Normative values presented here can help increase the practical application of instrumented balance assessment of mTBI patients through wearable sensors. ML RMS sway in the DS condition provided the clearest distinction between control and mTBI groups, but we caution that young adult athletes need to be assessed against athletic peers in the absence of baseline normative values. In non-athlete cohorts, age and gender norms may not be necessary to consider when assessing DS performance; however, age may be an important factor to consider when accessing norms for other stance conditions or the average performance across all conditions.

Head stabilization during standing in people with persisting symptoms after mild traumatic brain injury

Increased postural sway is often observed in people with mild traumatic brain injury (mTBI), but our understanding of how individuals with mTBI control their head during stance is limited. The purpose of this study was to determine if people with mTBI exhibit increased sway at the head compared with healthy controls. People with persisting symptoms after mTBI (n = 59, 41 women) and control participants (n = 63, 38 women) stood quietly for one minute in four conditions: eyes open on a firm surface (EO-firm), eyes closed on a firm surface (EC-firm), eyes open on a foam pad (EO-foam), and eyes closed on foam (EC-foam). Inertial sensors at the head, sternum, and lumbar region collected tri-axial accelerations. Root-mean-square (RMS) accelerations in anteroposterior (AP) and mediolateral (ML) directions and sway ratios between the head and sternum, head and lumbar, and sternum and lumbar region were compared between groups. Temporal coupling of anti-phase motion between the upper and lower body angular accelerations was assessed with magnitude squared coherence and cross-spectral phase angles. People with mTBI demonstrated greater sway than controls across conditions and directions. During foam-surface conditions, the control group, but not the mTBI group, reduced ML sway at their head and trunk relative to their lumbar by increasing the expression of an anti-phase hip strategy within the frontal plane. These results are consistent with suggestions of inflexible or inappropriate postural control in people with mTBI.

Reactive Postural Responses After Mild Traumatic Brain Injury and Their Association With Musculoskeletal Injury Risk in Collegiate Athletes: A Study Protocol

Background: Deficits in neuromuscular control are widely reported after mild traumatic brain injury (mTBI). These deficits are speculated to contribute to the increased rate of musculoskeletal injuries after mTBI. However, a concrete mechanistic connection between post-mTBI deficits and musculoskeletal injuries has yet to be established. While impairments in some domains of balance control have been linked to musculoskeletal injuries, reactive balance control has received little attention in the mTBI literature, despite the inherent demand of balance recovery in athletics. Our central hypothesis is that the high rate of musculoskeletal injuries after mTBI is in part due to impaired reactive balance control necessary for balance recovery. The purpose of this study is to (1) characterize reactive postural responses to recover balance in athletes with recent mTBI compared to healthy control subjects, (2) determine the extent to which reactive postural responses remain impaired in athletes with recent mTBI who have been cleared to return to play, and (3) determine the relationship between reactive postural responses and acute lower extremity musculoskeletal injuries in a general sample of healthy collegiate athletes.

Methods: This two-phase study will take place at the University of Utah in coordination with the University of Utah Athletics Department. Phase 1 will evaluate student-athletes who have sustained mTBI and teammate-matched controls who meet all the inclusion criteria. The participants will be assessed at multiple time points along the return-to-play progress of the athlete with mTBI. The primary outcome will be measures of reactive postural response derived from wearable sensors during the Push and Release (P&R) test. In phase 2, student-athletes will undergo a baseline assessment of postural responses. Acute lower extremity musculoskeletal injuries for each participant will be prospectively tracked for 1 year from the date of first team activity. The primary outcomes will be the measures of reactive postural responses and the time from first team activity to lower extremity injury.

Discussion: Results from this study will further our understanding of changes in balance control, across all domains, after mTBI and identify the extent to which postural responses can be used to assess injury risk in collegiate athletes.

Clinical and Device-based Metrics of Gait and Balance in Diagnosing Youth Concussion

PURPOSE

Evaluate the discriminatory ability of two clinical measures and one device-based measure of gait and balance for concussed youth.

METHODS

We enrolled 81 cases and 90 controls age 14-18 yr old from August 2017 to June 2018. Controls were recruited from a suburban high school, and cases were recruited from the concussion program of an academic pediatric tertiary care center. Tests included two clinical measures: 1) complex tandem gait, scored as sway/errors walking forward and backward eyes open and closed; 2) Modified Balance Error Scoring System (mBESS), scored as total number of errors on three standing tasks; and one device-based measure; 3) Modified Clinical Test of Sensory Interaction and Balance (mCTSIB) using the Biodex Biosway Balance System, scored as a sway index. Sensitivity, specificity, ideal cutpoint, and area under the receiver operating characteristic curve (AUC) were calculated for all test components.

RESULTS

Ideal cutpoint for total number of sway/errors for tandem gait = 5, sensitivity 41%, specificity 90%. Ideal cutpoint for total mBESS errors = 4, sensitivity 55%, specificity 75%. Ideal cutpoint for mCTSIB = 1.37, sensitivity 37%, specificity 88%. Among each test, some individual components outperformed overall composites, in particular tandem gait (specificity forward eyes open = 99%, sensitivity backward eyes closed = 81%). Among the 40 cases and 65 controls with all three assessments, AUC (95% CI) for tandem gait = 0.63 (0.52,0.75), mBESS = 0.70 (0.60,0.81), and mCTSIB = 0.54 (0.42,0.66).

CONCLUSIONS

A device-based measure of balance did not produce better discriminatory ability than two clinical assessments. Complex tandem gait has the additional benefit of being an easy-to-perform and graded test with highly sensitive and specific individual components.

A feasibility study towards instrumentation of the Sport Concussion Assessment Tool (iSCAT)

The Sports Concussion Assessment Tool (SCAT) is a pen and paper-based evaluation tool for use by healthcare professionals in the acute evaluation of suspected concussion. Here we present a feasibility study towards instrumented SCAT (iSCAT). Traditionally, a healthcare professional subjectively counts errors according to SCAT marking criteria matrix. It is hypothesized that an instrumented version of the test will be more accurate while providing additional digital-based parameters to better inform player management. The feasibility study focuses on the SCAT physical functioning tasks only: double leg stance, single-leg stance, tandem stance and tandem gait. Amateur university rugby players underwent iSCAT testing and data were recorded with 8 inertial units attached at different anatomical locations. Video data were gathered simultaneously as reference. An iSCAT algorithm was used to detect errors and quantify additional concussion-based time and frequency domain parameters to assess participant stability during balance and gait tasks. Future work aims to instrument other SCAT features such as hand-eye coordination while deploying methods within a large concussion project.

A preliminary cross-sectional assessment of postural control responses to continuous platform rotations following a sport-related concussion

BACKGROUND

Individuals suffering a sport-related concussion typically recover within 1 month; however, persistent post-concussive symptoms are known to occur beyond this period. Clinical guidelines may not be sufficient to determine if dynamic postural control is still impaired at the point of the return to play decision.

RESEARCH QUESTION

Do individuals with a previous sport-related concussion who have returned to play show differences in postural control compared to individuals without a previous concussion, in response to continuous platform perturbations?

METHODS

Eight previously concussed and eight age- and position-matched participants completed six one-minute trials (three with eyes open/closed) whilst stood on a moving platform that rotated about the pitch axis with a peak-to-peak amplitude of 4° at a frequency of 0.8 Hz. Six trials were also captured during static quiet stance for comparison. Reactive and anticipatory stages of postural control were analysed by determining anteroposterior margins of stability (MoS) as a measure of whole-body postural control and head-to-trunk anchoring index as an indication of the head-trunk segmental coupling strategy.

RESULTS

Posterior MoS during platform rotations reduced for both groups during eyes closed trials, but previously concussed participants exhibited a significantly greater reduction (1.97 cm) in comparison to matched-controls (0.34 cm). Participants, regardless of group, showed a preference towards a head-stabilised-to-trunk strategy during platform rotations. There were no differences during static trials.

SIGNIFICANCE

This preliminary study suggests previously concussed athletes demonstrate a greater reduction in postural control whilst undergoing continuous platform rotations with eyes closed, which could indicate possible lingering deficits to other sensory systems such as the vestibular system, though participants were not likely to lose their balance.

Concussion Recovery Evaluation Using the Inertial Sensor Instrumented Y Balance Test

The current sports concussion assessment paradigm lacks reliability, has learning effects, and is not sufficiently challenging for athletes. As a result, subtle deficits in sensorimotor function may be unidentified, increasing the risk of future injury. This study examined if the inertial-sensor instrumented Y Balance test could capture concussion-induced alterations in dynamic movement control. A cohort of 226 elite Rugby Union, American football, and ice hockey athletes were evaluated using the inertial-sensor instrumented Y balance test. Dynamic balance performance was quantified using normalized reach distance, jerk magnitude root-mean-squared (Jerk Mag RMS), and gyroscope magnitude sample entropy (Gyro Mag SEn). Concussed athletes who consented to follow-up were evaluated 24 to 48 h post-injury, and at the point of return to full contact training (RTP). Seventeen athletes sustained a concussion and consented to both the 24- to 48-h and RTP follow-up testing. Twenty uninjured control athletes were re-tested 6 months following initial screening. Concussed athletes had reductions in normalized reach distance (Cohens D = 0.66-1.16) and Jerk Mag (Cohens D = 0.57-1.14) 24 to 48 h post-injury, which returned to pre-injury levels by the point of RTP. There was no significant difference in performance between the baseline and 6-month follow-up in the 20 uninjured athletes (Cohens D = 0.06-0.51). There was a statistically significant linear association between Jerk Mag RMS 24 to 48 h post-injury and the natural log of RTP duration (R² = 0.27 to 0.33). These results indicate that concussed athletes possessed alterations in dynamic movement control 24 to 48 h post-concussion, which typically returns to pre-injury levels by the point of RTP. Further, evaluation of dynamic movement control 24 to 48 h post-injury may aid in the evaluation of recovery prognosis.

Fifteen Years of Wireless Sensors for Balance Assessment in Neurological Disorders

Balance impairment is a major mechanism behind falling along with environmental hazards. Under physiological conditions, ageing leads to a progressive decline in balance control per se. Moreover, various neurological disorders further increase the risk of falls by deteriorating specific nervous system functions contributing to balance. Over the last 15 years, significant advancements in technology have provided wearable solutions for balance evaluation and the management of postural instability in patients with neurological disorders. This narrative review aims to address the topic of balance and wireless sensors in several neurological disorders, including Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, stroke, and other neurodegenerative and acute clinical syndromes. The review discusses the physiological and pathophysiological bases of balance in neurological disorders as well as the traditional and innovative instruments currently available for balance assessment. The technical and clinical perspectives of wearable technologies, as well as current challenges in the field of teleneurology, are also examined.

Prognosis for Persistent Post Concussion Symptoms using a Multifaceted Objective Gait and Balance Assessment Approach

BACKGROUND

Concussion prognosis is a challenging clinical task. Identification of measures useful for persistent symptom risk can help optimize treatment pathways and allow clinicians to offer appropriate anticipatory guidance.

RESEARCH QUESTION

Can a multifaceted single/dual-task postural control assessment within one week of a diagnosed concussion identify the odds of developing persistent post-concussion symptoms (PPCS; symptoms that persist for more than 28 days post-concussion)?

METHODS

We conducted a prospective cohort study of youth and young adult athletes who were evaluated within 7 days of injury, and followed until they no longer reported concussion symptoms. Participants were grouped into those who developed PPCS and those who did not. During the initial evaluation, participants completed a postural control evaluation in single/dual-task conditions. We calculated six gait performance variables (in single/dual-task conditions), nine quiet stance performance variables, and three cognitive task performance (standing and walking) variables. We conducted between-group comparisons to identify candidate PPCS prognostic variables, and multivariable models to adjust for covariates (age, post-injury evaluation time, history of concussion, and BMI).

RESULTS

Sixty-six participants completed the study: 24% reported PPCS (mean age = 16.9 ± 3.5 years; 50% female; evaluated 4.2 ± 1.9 days post-injury) and 74% (mean age = 18.3 ± 3.0 years; 52% female; evaluated 3.5 ± 1.6 days post-injury) did not. Between-group comparisons indicated greater dual-task transverse plane center-of-mass (COM) range of motion (ROM) (13.1 ± 4.3 vs. 9.9 ± 2.5 degrees; p = 0.013) and lateral step variability (5.1 ± 1.4 vs. 4.0 ± 1.2 cm; p = 0.003) for the PPCS group relative to the no PPCS group. After multivariable modeling, dual-task transverse plane COM ROM (adjusted odds ratio = 1.34, 95% CI = 1.07, 1.68) and lateral step variability (adjusted odds ratio = 1.85, 95% CI = 1.13, 3.05) were significantly associated with PPCS.

SIGNIFICANCE

Dual-task transverse plane movement and lateral step variability demonstrate viable prognostic ability for PPCS among youth and young adult athletes and, along with other established factors, may add incremental value to PPCS prognosis models.

Inertial Sensors Reveal Subtle Motor Deficits When Walking With Horizontal Head Turns After Concussion

OBJECTIVE

To examine whether horizontal head turns while seated or while walking, when instrumented with inertial sensors, were sensitive to the acute effects of concussion and whether horizontal head turns had utility for concussion management.

SETTING

Applied field setting, athletic training room.

PARTICIPANTS

Twenty-four collegiate athletes with sports-related concussion and 25 healthy control athletes.

DESIGN

Case-control; longitudinal.

MAIN MEASURES

Peak head angular velocity and peak head angle (range of motion) when performing head turns toward an auditory cue while seated or walking. Gait speed when walking with and without head turns.

RESULTS

Athletes with acute sports-related concussion turned their head slower than healthy control subjects initially (group β = -49.47; SE = 16.33; P = .003) and gradually recovered to healthy control levels within 10 days postconcussion (group × time β = 4.80; SE = 1.41; P < .001). Peak head velocity had fair diagnostic accuracy in differentiating subjects with acute concussion compared with controls (areas under the receiver operating characteristic curve [AUC] = 0.71-0.73). Peak head angle (P = .17) and gait speed (P = .64) were not different between groups and showed poor diagnostic utility (AUC = 0.57-0.62).

CONCLUSION

Inertial sensors can improve traditional clinical assessments by quantifying subtle, nonobservable deficits in people following sports-related concussion.

Athletes with a concussion history in the last two years have impairments in dynamic balance performance

The purpose of this study was to determine if National Collegiate Athletics Association Division 1 American Football and Ice Hockey athletes with a history of concussion have impaired dynamic balance control when compared to healthy control athletes. This cross-sectional observational study recruited 146 athletes; 90 control athletes and 56 athletes with a history of concussion. Athletes were tested during a pre-season evaluation using the inertial-sensor instrumented Y Balance Test. Independent variables were normalized reach distance, gyroscope magnitude sample entropy, and jerk magnitude root mean square. Kruskal-Wallis H test and Dunn-Bonferroni analysis demonstrated that individuals with a concussion history within the last 2 years have statistically significantly lower jerk magnitude root mean square in the posteromedial (Z = 23.22, P = .015) and posterolateral (Z = 24.64, P = .010) reach directions, when compared to the control group. There was no significant difference between those who sustained a concussion longer than two years ago and the control group for the posteromedial (Z = -1.25; P = .889) and posterolateral (Z = 6.44; P = .469) directions. These findings show that athletes with a concussion history within the last two years possess dynamic balance deficits, when compared to healthy control athletes. Conversely, athletes whose injury occurred greater than 2 years ago possessed comparable performance to the healthy controls. This suggests that sensorimotor control deficits may persist beyond clinical recovery, for up to 2 years. Therefore, clinicians should integrate balance training interventions into the return-to-play process to accelerate sensorimotor recovery and mitigate the risk of future injury.

The effect of cognitive dual-tasks on dynamic postural sway during gait using inertial measurement units

OBJECTIVE

To investigate the influence of cognitive dual-tasks on dynamic postural sway variability, measured with a single inertial measurement unit, in healthy collegiate athletes during dual-task gait.

APPROACH

Thirty-four athletes ambulated down and back a 10-meter course. Root mean square values of postural sway acceleration were calculated for four sway-planes. Single and dual-task trial times were calculated from gait initiation to termination. Single and dual-task root mean square values were compared using Wilcoxon signed rank tests for each sway plane to determine significance. The relative difference between each sway measures and trial times for single and dual-task gait (i.e. dual-task cost was calculated). Spearman's correlation was used to analyze the association between dual-task cost of sway and trial time data.

MAIN RESULTS

During dual-task conditions, participants ambulated slower and demonstrated a significant reduction in root mean square sway in all planes of motion. The greatest decreases were in the medial-lateral (Z = -4.83, p < 0.001, ES = -0.83) and superior-inferior planes (Z = -4.93, p < 0.001, ES = -0.85). Increased trial time cost was associated with a decrease in dual-task cost of postural sway (p < 0.05).

SIGNIFICANCE

Performing a cognitive task while ambulating decreased postural sway variability in task-relevant planes of motion compared to single-task conditions. Reduced dual-task cost of sway variability during gait was associated with maintained trial times between single and dual-tasks. These data support the use of instrumented dual-task gait assessment to evaluate postural sway variability.

Capturing concussion related changes in dynamic balance using the Quantified Y Balance Test - a case series of six elite rugby union players

Concussion is one of the most common injuries reported across a myriad of sports. Recent evidence suggests that individuals may possess sensorimotor deficits beyond clinical recovery, predisposing them to further injury. This preliminary prospective case series aimed to determine if an inertial sensor instrumented Y balance test can capture changes in dynamic balance, regardless of apparent `clinical recovery', in six concussed elite rugby union players. The findings from this case series demonstrate that the inertial sensor-based measures can detect clinically meaningful changes in dynamic balance performance, not captured by the traditional clinical scoring methods, 48-hours post-injury and at the point of `clinical recovery' (return to play). Further research should investigate the role such instrumented dynamic balance assessments may play in the management of sports-related concussion.

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

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