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Objectives: To assess changes in health-related quality of life (HRQOL) across a 12-month period following pediatric concussion and to explore whether psychological factors (ie, pre-injury mental health history, current symptoms of anxiety and depression, sleep disturbance, or grit) were associated with HRQOL., Study Design: Prospective cohort study design using data collected from patients presenting to a speciality care concussion program, with each patient followed for 12 months after initial presentation. Comparison data were collected from non-concussed controls recruited from the community. A total of 49 concussed patients (median=15.4 years of age) completed the Pediatric Quality of Life Inventory (PedsQL), Patient-Reported Outcome Measure Information Systems (PROMIS) Anxiety and Depressive Symptoms short forms, Pediatric Sleep Disturbance forms, and a Short Grit Scale. Mixed effects models explored change in HRQOL across time., Results: Total HRQOL at initial clinic presentation was significantly lower for concussed adolescents (Peds QL Total Score mean=72 [SD=16 ]) compared with non-concussed controls (mean=88 [SD=11], p <.001). HRQOL improved in the patients with concussion over a 6-month period after initial assessment with no significant changes thereafter. Pre-injury history of anxiety (coefficient= -11.388, CI=-18.49 - -4.28, p<0.001), current depressive symptoms (coefficient= -0.317, CI= -0.62 - -0.01, p<0.01), and sleep disturbance (coefficient=-0.336, CI=-0.71 - 0.04, p<0.05) all predicted lower HRQOL., Conclusions: HRQOL is significantly lower in the acute phase of pediatric concussion and steadily improves over the following 6 months. Psychological factors are linked to lower HRQOL and may serve as important indicators of risk for poor outcome., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Finite element (FE) modeling provides a means to examine how global kinematics of repetitive head loading in sports influences tissue level injury metrics. FE simulations of controlled soccer headers in two directions were completed using a human head FE model to estimate biomechanical loading on the brain by direction. Overall, headers were associated with 95th percentile peak maximum principal strains up to 0.07 and von Mises stresses up to 1450 Pa, and oblique headers trended toward higher values than frontal headers but below typical injury levels. These quantitative data provide insight into repetitive loading effects on the brain.

Neurovascular coupling (NVC) uniquely describes cerebrovascular response to neural activation and has demonstrated impairments following concussion in adult patients. It is currently unclear how adolescent patients experience impaired NVC acutely following concussion during this dynamic phase of physiological development. The purpose of this study was to investigate NVC in acutely concussed adolescent patients relative to controls. We recruited patients presenting to a sports medicine practice within 28 days of a concussion or a musculoskeletal injury (controls). Transcranial Doppler ultrasound was used to measure changes in patients' posterior cerebral artery (PCA) velocity in response to two progressively challenging visual tasks: (1) reading and (2) visual search. Each task was presented in five 1-min trials (20 sec eyes closed/40 sec eyes open). Resting PCA velocity data were derived by averaging PCA velocity across a 2-min baseline period that preceded the visual tasks. Filtered task data were converted to time-series curves representing 40 consecutive 1-sec averages for each trial. Curves were then averaged across the five trials and time-aligned to stimulus onset (eyes open) to generate a single ensemble-averaged 40-sec curve representing NVC response for each participant for each task. Independent t tests were used to assess group differences (concussion vs. control) in resting PCA velocity. Separate linear mixed-effects models were used to evaluate group differences (concussion vs. control) in NVC response profiles for both visual tasks and group-by-task interaction. Twenty-one concussion patients (female = 8 [38.1%]; age = 14.4 ± 1.9 years) and 20 controls (female = 7 [35.0%]; age = 14.4 ± 1.9 years) were included in our analysis. Average resting PCA velocity did not significantly differ between concussion patients (36.6 ± 8.0 cm/sec) and controls (39.3 ± 8.5 cm/sec) ( t 39  = 1.06; p  = 0.30). There were no significant group differences in relative NVC response curves during the reading task ( F 1,1560  = 2.23; p  = 0.14) or the visual search task ( F 1,1521  = 2.04; p  = 0.15). In contrast, the differential response to task (e.g., increase from reading task to visual search task) was significantly greater in concussion patients than in controls ( p  < 0.0001). The NVC response to the visual search task was 7.1% higher than the response to reading in concussion patients relative to being 5.5% higher in controls. Our data indicate that concussed patients present with a significantly greater response to more difficult tasks than do controls, suggesting that concussed adolescents require increased neural resource allocation as task difficulty increases. The study provides insight into the neurophysiological consequences of concussion in adolescent patients.

Introduction: Paediatric concussion is a common injury. Approximately 30% of youth with concussion will experience persisting postconcussion symptoms (PPCS) extending at least 1 month following injury. Recently, studies have shown the benefit of early, active, targeted therapeutic strategies. However, these are primarily prescribed from the specialty setting. Early access to concussion specialty care has been shown to improve recovery times for those at risk for persisting symptoms, but there are disparities in which youth are able to access such care. Mobile health (mHealth) technology has the potential to improve access to concussion specialists. This trial will evaluate the feasibility of a mHealth remote patient monitoring (RPM)-based care handoff model to facilitate access to specialty care, and the effectiveness of the handoff model in reducing the incidence of PPCS., Methods and Analysis: This study is a non-randomised type I, hybrid implementation-effectiveness trial. Youth with concussion ages 13-18 will be enrolled from the emergency department of a large paediatric healthcare network. Patients deemed a moderate-to-high risk for PPCS using the predicting and preventing postconcussive problems in paediatrics (5P) stratification tool will be registered for a web-based chat platform that uses RPM to collect information on symptoms and activity. Those patients with escalating or plateauing symptoms will be contacted for a specialty visit using data collected from RPM to guide management. The primary effectiveness outcome will be the incidence of PPCS, defined as at least three concussion-related symptoms above baseline at 28 days following injury. Secondary effectiveness outcomes will include the number of days until return to preinjury symptom score, clearance for full activity and return to school without accommodations. The primary implementation outcome will be fidelity, defined as the per cent of patients meeting specialty care referral criteria who are ultimately seen in concussion specialty care. Secondary implementation outcomes will include patient-defined and clinician-defined appropriateness and acceptability., Ethics and Dissemination: This study was approved by the Institutional Review Board of the Children's Hospital of Philadelphia (IRB 22-019755). Study findings will be published in peer-reviewed journals and disseminated at national and international meetings., Trial Registration Number: NCT05741411., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To investigate characteristics of sport-related concussion (SRC), recreation-related concussion (RRC), and nonsport or recreation-related concussion (non-SRRC) in patients 5 through 12 years old, an understudied population in youth concussion., Study Design: This observational study included patients aged 5 through 12 years presenting to a specialty care concussion setting at ≤28 days postinjury from 2018 through 2022. The following characteristics were assessed: demographics, injury mechanism (SRC, RRC, or SRRC), point of healthcare entry, and clinical signs and symptoms. Kruskal-Wallis and chi-square tests were used to assess group differences. Posthoc pairwise comparisons were employed for all analyses (α = 0.017)., Results: One thousand one hundred forty-one patients reported at ≤28 days of injury (female = 42.9%, median age = 11, interquartile range (IQR) = 9-12) with the most common mechanism being RRC (37.3%), followed by non-SRRC (31.9%). More non-SRRCs (39.6%) and RRC (35.7%) were first seen in the emergency department (P < .001) compared with SRC (27.9%). Patients with RRC and non-SRRC were first evaluated at specialists 2 and 3 days later than SRC (P < .001). Patients with non-SRRC reported with higher symptom burden, more frequent visio-vestibular abnormalities, and more changes to sleep and daily habits (P < .001) compared with RRC and SRC (P < .001)., Conclusions: In concussion patients 5 through 12 years, RRCs and non-SRRC were more prevalent than SRC, presenting first more commonly to the emergency department and taking longer to present to specialists. Non-SRRC had more severe clinical features. RRC and non-SRRC are distinct from SRC in potential for less supervision at time of injury and less direct access to established concussion health care following injury., Competing Interests: Declaration of Competing Interest This study was funded by the National Institute of Neurologic Disorders and Stroke of the National Institutes of Health under award numbers R01NS097549 (Christina Master and Kristy Arbogast) and T32NS043126 (Patricia Roby) and the Pennsylvania Department of Health. The authors declare no conflicts of interest. The funder/sponsor did not participate in the work., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Concussion is a common injury in the adolescent and young adult populations. Although branched chain amino acid (BCAA) supplementation has shown improvements in neurocognitive and sleep function in pre-clinical animal models of mild-to-moderate traumatic brain injury (TBI), to date, no studies have been performed evaluating the efficacy of BCAAs in concussed adolescents and young adults. The goal of this pilot trial was to determine the efficacy, tolerability, and safety of varied doses of oral BCAA supplementation in a group of concussed adolescents and young adults. The study was conducted as a pilot, double-blind, randomized controlled trial of participants ages 11-34 presenting with concussion to outpatient clinics (sports medicine and primary care), urgent care, and emergency departments of a tertiary care pediatric children's hospital and an urban tertiary care adult hospital, between June 24, 2014 and December 5, 2020. Participants were randomized to one of five study arms (placebo and 15 g, 30 g, 45 g, and 54 g BCAA treatment daily) and followed for 21 days after enrollment. Outcome measures included daily computerized neurocognitive tests (processing speed, the a priori primary outcome; and attention, visual learning, and working memory), symptom score, physical and cognitive activity, sleep/wake alterations, treatment compliance, and adverse events. In total, 42 participants were randomized, 38 of whom provided analyzable data. We found no difference in our primary outcome of processing speed between the arms; however, there was a significant reduction in total symptom score (decrease of 4.4 points on a 0-54 scale for every 500 g of study drug consumed, p value for trend = 0.0036, [uncorrected]) and return to physical activity (increase of 0.503 points on a 0-5 scale for every 500 g of study drug consumed, p value for trend = 0.005 [uncorrected]). There were no serious adverse events. Eight of 38 participants reported a mild (not interfering with daily activity) or moderate (limitation of daily activity) adverse event; there were no differences in adverse events by arm, with only two reported mild adverse events (both gastrointestinal) in the highest (45 g and 54 g) BCAA arms. Although limited by slow enrollment, small sample size, and missing data, this study provides the first demonstration of efficacy, as well as safety and tolerability, of BCAAs in concussed adolescents and young adults; specifically, a dose-response effect in reducing concussion symptoms and a return to baseline physical activity in those treated with higher total doses of BCAAs. These findings provide important preliminary data to inform a larger trial of BCAA therapy to expedite concussion recovery.

Background: A concussion is a common adolescent injury that can result in a constellation of symptoms, negatively affecting academic performance, neurobiological development, and quality of life. Mobile health (mHealth) technologies, such as apps for patients to report symptoms or wearables to measure physiological metrics like heart rate, have been shown to be promising in health maintenance. However, there is limited evidence about mHealth engagement in adolescents with a concussion during their recovery course., Objective: This study aims to determine the response rate and response rate patterns in concussed adolescents reporting their daily symptoms through mHealth technology. It will also examine the effect of time-, demographic-, and injury-related characteristics on response rate patterns., Methods: Participants aged between 11-18 years (median days since injury at enrollment: 11 days) were recruited from the concussion program of a tertiary care academic medical center and a suburban school's athletic teams. They were asked to report their daily symptoms using a mobile app. Participants were prompted to complete the Post-Concussion Symptom Inventory (PCSI) 3 times (ie, morning, afternoon, and evening) per day for 4 weeks following enrollment. The primary outcome was the response rate pattern over time (by day since initial app use and the day since injury). Time-, demographic-, and injury-related differences in reporting behaviors were compared using Mann Whitney U tests., Results: A total of 56 participants were enrolled (mean age 15.3, SD 1.9 years; n=32, 57% female). The median response rate across all days of app use in the evening was 37.0% (IQR 27.2%-46.4%), which was significantly higher than the morning (21.2%, IQR 15.6%-30.5%) or afternoon (26.4%, IQR 21.1%-31.5%; P<.001). The median daily response was significantly different by sex (female: 53.8%, IQR 46.2%-64.2% vs male: 42.0%, IQR 28.6%-51.1%; P=.003), days since injury to app use (participants starting to use the app >7 days since injury: 54.1%, IQR 47.4%-62.2% vs starting to use the app ≤7 days since injury: 38.0%, IQR 26.0%-53.3%; P=.002), and concussion history (participants with a history of at least one prior concussion: 57.4%, IQR 44.5%-70.5% vs participants without concussion history: 42.3%, IQR 36.8%-53.5%; P=.03). There were no significant differences by age. Differences by injury mechanism (sports- and recreation-related injury: 39.6%, IQR 36.1%-50.4% vs non-sports- or recreation-related injury: 30.6%, IQR 20.0%-42.9%; P=.04) and initial symptom burden (PCSI scores greater than the median score of 47: 40.9%, IQR 35.2%-53.8% vs PCSI scores less than or equal to the median score: 31.9%, IQR 24.6%-40.6%; P=.04) were evident in the evening response rates; however, daily rates were not statistically different., Conclusions: Evening may be the optimal time to prompt for daily concussion symptom assessment among concussed adolescents compared with morning or afternoon. Multiple demographic- and injury-related characteristics were associated with higher daily response rates, including for female participants, those with more than 1 week from injury to beginning mHealth monitoring, and those with a history of at least one previous concussion. Future studies may consider incentive strategies or adaptive digital concussion assessments to increase response rates in populations with low engagement., (© Sicong Ren, Catherine C McDonald, Daniel J Corwin, Douglas J Wiebe, Christina L Master, Kristy B Arbogast. Originally published in JMIR Pediatrics and Parenting (https://pediatrics.jmir.org).)

Male lacrosse and female lacrosse have differences in history, rules, and equipment. There is current debate regarding the need for enhanced protective headwear in female lacrosse like that worn by male lacrosse players. To inform this discussion, 17 high school lacrosse players (6 female and 11 male) wore the Stanford Instrumented Mouthguard during 26 competitive games over the 2021 season. Time-windowing and video review were used to remove false-positive recordings and verify head acceleration events (HAEs). The HAE rate in high school female lacrosse (0.21 per athlete exposure and 0.24 per player hour) was approximately 35% lower than the HAE rate in high school male lacrosse (0.33 per athlete exposure and 0.36 per player hour). Previously collected kinematics data from the 2019 high school male and female lacrosse season were combined with the newly collected 2021 kinematics data, which were used to drive a finite element head model and simulate 42 HAEs. Peak linear acceleration (PLA), peak angular velocity (PAV), and 95th percentile maximum principal strain (MPS95) of brain tissue were compared between HAEs in high school female and male lacrosse. Median values for peak kinematics and MPS95 of HAEs in high school female lacrosse (PLA, 22.3 g; PAV, 10.4 rad/s; MPS95, 0.05) were lower than for high school male lacrosse (PLA, 24.2 g; PAV, 15.4 rad/s; MPS95, 0.07), but the differences were not statistically significant. Quantifying a lower HAE rate in high school female lacrosse compared to high school male lacrosse, but similar HAE magnitudes, provides insight into the debate regarding helmets in female lacrosse. However, due to the small sample size, additional video-verified data from instrumented mouthguards are required., (© 2024. The Author(s) under exclusive licence to Biomedical Engineering Society.)

Background: Studies have evaluated individual factors associated with persistent postconcussion symptoms (PPCS) in youth concussion, but no study has combined individual elements of common concussion batteries with patient characteristics, comorbidities, and visio-vestibular deficits in assessing an optimal model to predict PPCS., Purpose: To determine the combination of elements from 4 commonly used clinical concussion batteries and known patient characteristics and comorbid risk factors that maximize the ability to predict PPCS., Study Design: Cohort study; Level of evidence, 2., Methods: We enrolled 198 concussed participants-87 developed PPCS and 111 did not-aged 8 to 19 years assessed within 14 days of injury from a suburban high school and the concussion program of a tertiary care academic medical center. We defined PPCS as a Post-Concussion Symptom Inventory (PCSI) score at 28 days from injury of ≥3 points compared with the preinjury PCSI score-scaled for younger children. Predictors included the individual elements of the visio-vestibular examination (VVE), Sport Concussion Assessment Tool, 5th Edition (SCAT-5), King-Devick test, and PCSI, in addition to age, sex, concussion history, and migraine headache history. The individual elements of these tests were grouped into interpretable factors using sparse principal component analysis. The 12 resultant factors were combined into a logistic regression and ranked by frequency of inclusion into the combined optimal model, whose predictive performance was compared with the VVE, initial PCSI, and the current existing predictive model (the Predicting and Prevention Postconcussive Problems in Pediatrics (5P) prediction rule) using the area under the receiver operating characteristic curve (AUC)., Results: A cluster of 2 factors (SCAT-5/PCSI symptoms and VVE near point of convergence/accommodation) emerged. A model fit with these factors had an AUC of 0.805 (95% CI, 0.661-0.929). This was a higher AUC point estimate, with overlapping 95% CIs, compared with the PCSI (AUC, 0.773 [95% CI, 0.617-0.912]), VVE (AUC, 0.736 [95% CI, 0.569-0.878]), and 5P Prediction Rule (AUC, 0.728 [95% CI, 0.554-0.870])., Conclusion: Among commonly used clinical assessments for youth concussion, a combination of symptom burden and the vision component of the VVE has the potential to augment predictive power for PPCS over either current risk models or individual batteries., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: Funding for this research has been provided by the Pennsylvania Department of Health. Research reported in this publication was also supported by the National Institute of Neurological Disorders and Stroke of the NIH under award No. R01NS097549 awarded to K.B.A. and C.L.M. and the National Institute of Neurological Disorders and Stroke of the NIH under award No. K23NS128275-01 awarded to D.J.C. C.L.M. has received a grant from DJO. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Pre-existing mental health diagnoses may contribute to greater emotional symptom burden and prolonged recovery after concussion., Hypothesis: Youth with pre-existing mental health diagnoses will have greater emotional symptom burden, greater risk for delayed return to exercise, and more prolonged recovery from concussion than those without those diagnoses., Study Design: Prospective cohort., Level of Evidence: Level 3., Methods: A prospective registry of youth concussion was examined for differences in emotional symptom burden after injury to develop a predictive risk model for prolonged recovery. The impact of individual and total number of pre-existing mental health diagnoses (0, 1, 2, and 3+) was assessed, and multivariable logistic regression was performed to identify factors associated with prolonged recovery., Results: Among a cohort of 3105 youth with concussion, those with a history of mental health diagnoses, in a dose-response fashion, had greater postinjury emotional symptom burden (7 emotional symptoms vs 4; P < 0.01), visio-vestibular dysfunction (65% abnormal vs 56% abnormal; P < 0.01), later return to symptom-limited exercise (23 vs 21 days; P < 0.01), and overall longer concussion recovery (38 days, interquartile range [IQR] 18, 80) versus 25 days (IQR 13, 54; P < 0.01). Boys with prolonged recovery after concussion had greater emotional symptom burden than girls (5 emotional symptoms vs 3; P < 0.01)., Conclusion: Pre-existing mental health diagnoses are associated with greater postinjury emotional symptom burden and longer concussion recovery in a dose-response fashion. Visiovestibular deficits and delayed return to exercise are also associated with pre-existing mental health diagnoses and prolonged recovery. Boys with prolonged recovery from concussion experience greater emotional symptom burden than girls., Clinical Relevance: Addressing pre-existing mental health diagnoses is essential to concussion management. Boys with prolonged recovery from concussion may particularly benefit from interventions to address their higher emotional symptom burden. Interventions, including a home visio-vestibular exercise program and symptom-limited exercise, may contribute to improving time to concussion recovery., Competing Interests: The following author declared potential conflicts of interest: C.L.M. has received speaking fees from the AAP, AAOPT, Indiana University, Nationwide Children’s Hospital, and NYU Concussion.

Context: Concussion research has primarily focused on sport-related mechanisms and excluded non-sport-related mechanisms. In adult populations, non-sport-related concussions (non-SRCs) demonstrated worse clinical outcomes compared with sport-related concussions (SRCs); however, investigations of non-SRCs in college-aged patients are limited., Objectives: To examine clinical outcomes in collegiate athletes with non-SRCs compared with SRCs and explore sex differences in outcomes among collegiate athletes with non-SRCs., Design: Prospective cohort study., Setting: Clinical setting., Patients or Other Participants: A total of 3500 athletes were included (n = 555 with non-SRCs, 42.5% female) from colleges or universities and service academies participating in the National Collegiate Athletic Association Department of Defense Concussion Assessment, Research and Education (CARE) Consortium., Main Outcome Measure(s): Dichotomous outcomes (yes or no) consisted of immediate reporting, mental status alterations, loss of consciousness, posttraumatic amnesia, retrograde amnesia, motor impairments, delayed symptom presentation, and required hospital transport. Continuous outcomes were symptom severity, days with concussion symptoms, and days lost to injury. Data were collected within 24 to 48 hours of injury and at return to play. Adjusted relative risks (ARRs) compared the likelihood of dichotomous outcomes by mechanism and by sex within patients with non-SRCs. Multivariate negative binomial regressions were used to assess group differences in continuous variables., Results: Athletes with non-SRCs were less likely to report immediately (ARR = 0.73, 95% CI = 0.65, 0.81) and more likely to report delayed symptom presentation (ARR = 1.17, 95% CI = 1.03, 1.32), loss of consciousness (ARR = 3.15, 95% CI = 2.32, 4.28), retrograde amnesia (ARR = 1.77, 95% CI = 1.22, 2.57), and motor impairment (ARR = 1.45, 95% CI = 1.14, 1.84). Athletes with non-SRCs described greater symptom severity, more symptomatic days, and more days lost to injury (P < .001) compared with those who had SRCs. Within the non-SRC group, female athletes indicated greater symptom severity, more symptomatic days, and more days lost to injury (P < .03) than male athletes., Conclusions: Athletes with non-SRCs had worse postinjury outcomes compared with those who had SRCs, and female athletes with non-SRCs had worse recovery metrics than male athletes. Our findings suggest that further investigation of individuals with non-SRCs is needed to improve concussion reporting and management., (© by the National Athletic Trainers’ Association, Inc.)

Background: While concussions are common pediatric injuries, a lack of agreement on a standard definition of recovery creates multiple challenges for clinicians and researchers alike., Hypothesis: The percentage of concussed youth deemed recovered as part of a prospective cohort study will differ depending on the recovery definition., Study Design: Descriptive epidemiologic study of a prospectively enrolled observational cohort., Level of Evidence: Level 3., Methods: Participants aged 11 to 18 years were enrolled from the concussion program of a tertiary care academic center. Data were collected from initial and follow-up clinical visits ≤12 weeks from injury. A total of 10 recovery definitions were assessed: (1) cleared to full return to sports; (2) return to full school; (3) self-reported return to normal; (4) self-reported full return to school; (5) self-reported full return to exercise; (6) symptom return to preinjury state; (7) complete symptom resolution; (8) symptoms below standardized threshold; (9) no abnormal visio-vestibular examination (VVE) elements; and (10) ≤1 abnormal VVE assessments., Results: In total, 174 participants were enrolled. By week 4, 63.8% met at least 1 recovery definition versus 78.2% by week 8 versus 88.5% by week 12. For individual measures of recovery at week 4, percent recovered ranged from 5% by self-reported full return to exercise to 45% for ≤1 VVE abnormality (similar trends at 8 and 12 weeks)., Conclusion: There is wide variability in the proportion of youth considered recovered at various points following concussion depending on the definition of recovery, with higher proportions using physiologic examination-based measures and lower proportions using patient-reported measures., Clinical Relevance: These results further emphasize the need for a multimodal assessment of recovery by clinicians as a single and standardized definition of recovery that captures the broad impact of concussion on a given patient continues to be elusive., Competing Interests: The following authors declared potential conflicts of interest: K.B.M., C.C.M., M.R.P., K.B.A., and C.L.M. received a grant from Pennsylvania Department of Health (DOH). K.B.A. and C.L.M. received grant R01NS097549 from the National Institute of Neurological Disorders and Stroke.

Disruptions in gait function are common after concussion in adolescents; however, the neuromotor control deficits driving these gait disruptions are not well known. Fifteen concussed (age mean [SD]): 17.4 [0.6], 13 females, days since injury: 26.3 [9.9]) and 17 uninjured (age: 18.0 [0.7], 10 females) adolescents completed 3 trials each of single-task gait and dual-task gait (DT). During DT, participants simultaneously walked while completing a serial subtraction task. Gait metrics and variability in instantaneous mean frequency in lower extremity muscles were captured by inertial sensors and surface electromyography, respectively. A 2-way analysis of covariance was used to compare gait metrics across groups and conditions. Functional principal components analysis was used to identify regions of variability in instantaneous mean frequency curves. Functional principal component scores were compared across groups using a Welch statistic. Both groups displayed worse performance on gait metrics during DT condition compared to single-task, with no differences between groups (P < .001). Concussed adolescents displayed significantly greater instantaneous mean frequency, indicated by functional principal component 1, in the tibialis anterior, biceps femoris, and semitendinosus (P < .05) during single-task and DT compared with uninjured adolescents. Our observations suggest that concussed adolescents display inefficient motor unit recruitment lasting longer than 2 weeks following injury, regardless of the addition of a secondary task.

Objective: To describe menstrual cycle patterns in adolescents with concussion and investigate whether menstrual cycle phase at injury influenced postconcussion cycle pattern changes or concussion symptoms., Study Design: Data were collected prospectively from patients aged 13-18 years presenting to a specialty care concussion clinic for an initial visit (≤28 days postconcussion) and, if clinically indicated, at a follow-up visit 3-4 months postinjury. Primary outcomes included menstrual cycle pattern change since injury (change/no change), menstrual cycle phase at time of injury (calculated using date of last period before injury), and symptom endorsement and severity, measured by Post-Concussion Symptom Inventory (PCSI). Fisher exact tests were used to determine the association between menstrual phase at injury and change in cycle pattern. Multiple linear regression was used to determine whether menstrual phase at injury was associated with PCSI endorsement and symptom severity, adjusting for age., Results: Five hundred twelve postmenarchal adolescents were enrolled (age 15.2 ± 1.4 years), with 111 (21.7%) returning for follow-up at 3-4 months. Menstrual pattern change was reported by 4% of patients at initial visit and 10.8% of patients at follow-up. At 3-4 months, menstrual phase at injury was not associated with menstrual cycle changes (P = .40) but was associated with endorsement of concussion symptoms on the PCSI (P = .01)., Conclusions: At 3-4 months' postconcussion, 1 in 10 adolescents experienced a change in menses. Menstrual cycle phase at injury was associated with postconcussion symptom endorsement. Leveraging a large sample of postconcussion menstrual patterns, this study represents foundational data regarding potential menstrual cycle effects of concussion in female adolescents., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Context: Multiple clinical evaluation tools exist for adolescent concussion with various degrees of correlation, presenting challenges for clinicians in identifying which elements of these tools provide the greatest diagnostic utility., Objective: To determine the combination of elements from 4 commonly used clinical concussion batteries that maximize discrimination of adolescents with concussion from those without concussion., Design: Cross-sectional study., Setting: Suburban school and concussion program of a tertiary care academic center., Patients or Other Participants: A total of 231 participants with concussion (from a suburban school and a concussion program) and 166 participants without concussion (from a suburban school) between the ages of 13 and 19 years., Main Outcome Measure(s): Individual elements of the visio-vestibular examination (VVE), Sport Concussion Assessment Tool, fifth edition (SCAT5; including the modified Balance Error Scoring System), King-Devick test (K-D), and Postconcussion Symptom Inventory (PCSI) were evaluated. The 24 subcomponents of these tests were grouped into interpretable factors using sparse principal component analysis. The 13 resultant factors were combined with demographic and clinical covariates into a logistic regression model and ranked by frequency of inclusion into the ideal model, and the predictive performance of the ideal model was compared with each of the clinical batteries using the area under the receiver operating characteristic curve (AUC)., Results: A cluster of 4 factors (factor 1 [VVE saccades and vestibulo-ocular reflex], factor 2 [modified Balance Error Scoring System double-legged stance], factor 3 [SCAT5/PCSI symptom scores], and factor 4 [K-D completion time]) emerged. A model fit with the top factors performed as well as each battery in predicting concussion status (AUC = 0.816 [95% CI = 0.731, 0.889]) compared with the SCAT5 (AUC = 0.784 [95% CI = 0.692, 0.866]), PCSI (AUC = 0.776 [95% CI = 0.674, 0.863]), VVE (AUC = 0.711 [95% CI = 0.602, 0.814]), and K-D (AUC = 0.708 [95% CI = 0.590, 0.819])., Conclusions: A multifaceted assessment for adolescents with concussion, comprising symptoms, attention, balance, and the visio-vestibular system, is critical. Current diagnostic batteries likely measure overlapping domains, and the sparse principal component analysis demonstrated strategies for streamlining comprehensive concussion assessment across a variety of settings., (© by the National Athletic Trainers’ Association, Inc.)

Background: Gait deficits are common after concussion in adolescents. However, the neurophysiological underpinnings of these gait deficiencies are currently unknown. Thus, the goal of this study was to compare spatiotemporal gait metrics, prefrontal cortical activation, and neural efficiency between concussed adolescents several weeks from injury and uninjured adolescents during a dual-task gait assessment., Methods: Fifteen concussed (mean age[SD]: 17.4[0.6], 13 female, days since injury: 26.3[9.9]) and 17 uninjured adolescents (18.0[0.7], 10 female) completed a gait assessment with three conditions repeated thrice: single-task walking, single-task subtraction, and dual-task, which involved walking while completing a subtraction task simultaneously. Gait metrics were measured using an inertial sensor system. Prefrontal cortical activation was captured via functional near-infrared spectroscopy. Neural efficiency was calculated by relating gait metrics to prefrontal cortical activity. Differences between groups and conditions were examined, with corrections for multiple comparisons., Findings: There were no significant differences in gait metrics between groups. Compared to uninjured adolescents, concussed adolescents displayed significantly greater prefrontal cortical activation during the single-task subtraction (P = 0.01) and dual-task (P = 0.01) conditions with lower neural efficiency based on cadence (P = 0.02), gait cycle duration (P = 0.03), step duration (P = 0.03), and gait speed (P = 0.04) during the dual-task condition., Interpretation: Our findings suggest that several weeks after injury concussed adolescents demonstrate lower neural efficiency and display a cost to gait performance when cognitive demand is high, e.g., while multitasking, suggesting that the concussed adolescent brain is less able to compensate when attention is divided between two concurrent tasks., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kristy Arbogast, PhD and Christina Master, MD report financial support was provided by the National Institute of Neurological Disorders and Stroke. Catherine McDonald, PhD reports financial support was provided by the National Institue of Nursing Research. Hasan Ayaz, PhD reports a relationship with fNIR Devices, LLC that includes: equity or stocks., (Copyright © 2023. Published by Elsevier Ltd.)

Repeated head loading in sports is associated with negative long-term brain health, and there is growing evidence of short-term neurophysiological changes after repeated soccer heading. The objective of this study was to quantify the head kinematics and effects of repetitive soccer headers in adolescents using an instrumented mouthguard. Adolescent soccer players aged 13-18 years were randomly assigned to a kicking control, frontal heading, or oblique heading group. Participants completed neurophysiological assessments at three-time points: immediately prior to, immediately after, and approximately 24 h after completing 10 headers or kicks. The suite of assessments included the Post-Concussion Symptom Inventory, visio-vestibular exam, King-Devick test, modified Clinical Test of Sensory Interaction and Balance with force plate sway measurement, pupillary light reflex, and visual evoked potential. Data were collected for 19 participants (17 male). Frontal headers resulted in significantly higher peak resultant linear acceleration (17.4 ± 0.5 g) compared to oblique headers (12.1 ± 0.4 g, p < 0.001), and oblique headers resulted in significantly higher peak resultant angular acceleration (frontal: 1147 ± 45 rad/s2, oblique: 1410 ± 65 rad/s2, p < 0.001). There were no neurophysiological deficits for either heading group or significant differences from controls at either post-heading timepoint, and therefore, a bout of repeated headers did not result in changes in the neurophysiological measures evaluated in this study. The current study provided data regarding the direction of headers with the goal to reduce the risk of repetitive head loading for adolescent athletes., (Copyright © 2023 by ASME.)

Objective: To quantify the head and neck injury metrics of an anthropometric test device (ATD) in a rearward-facing child restraint system (CRS), with and without a support leg, in frontal-oblique impacts., Methods: Sled tests using the Federal Motor Vehicle Safety Standards (FMVSS) 213 frontal crash pulse (48 km/h, 23 g) were performed with a simulated Consumer Reports test buck, which comprised a test bench that mimics the rear outboard vehicle seat of a sport utility vehicle (SUV). The test bench was rigidised to increase durability for repeated testing and the seat springs and cushion were replaced every five tests. A force plate was mounted to the floor of the test buck directly in front of the test bench to measure support leg peak reaction force. The test buck was rotated 30° and 60° relative to the longitudinal axis of the sled deck to represent frontal-oblique impacts. The door surrogate from the FMVSS 213a side impact test was rigidly attached to the sled deck adjacent to the test bench. The 18-month-old Q-Series (Q1.5) ATD was seated in a rearward-facing infant CRS, which was attached to the test bench with either rigid lower anchors or a three-point seatbelt. The rearward-facing infant CRS was tested with and without a support leg. Conductive foil was attached to the upper edge of the door panel and a strip of conductive foil was attached to the top of the ATD head so that a voltage signal quantified contact with the door panel. A new CRS was used for each test. A repeat test was performed for each condition for a total of 16 tests., Data Sources: Resultant linear head acceleration 3 ms clip; head injury criterion 15 ms (HIC15); peak neck tensile force; peak neck flexion moment; potential difference between the ATD head and the door panel; support leg peak reaction force., Results: The presence of a support leg significantly reduced head injury metrics (p < 0.001) and peak neck tensile force (p = 0.004) compared to tests without a support leg. Rigid lower anchors were associated with significant reductions in head injury metrics and peak neck flexion moment (p < 0.001) compared to tests that attached the CRS with the seatbelt. The 60° frontal-oblique tests had significantly elevated head injury metrics (p < 0.01) compared to the 30° frontal-oblique tests. No ATD head contact with the door was observed for 30° frontal-oblique tests. The ATD head contacted the door panel in the 60° frontal-oblique tests when the CRS was tested without the support leg. Average support leg peak reaction forces ranged from 2167 to 4160 N. The 30° frontal-oblique sled tests had significantly higher support leg peak reaction forces (p < 0.001) compared to the 60° frontal-oblique sled tests., Conclusions: The findings of the current study add to the growing body of evidence regarding the protective benefits of CRS models with a support leg and rigid lower anchors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

There is concern that repetitive head impact exposure (RHIE) may lead to neurophysiological deficits in adolescents. Twelve high school varsity soccer players (5 female) completed the King-Devick (K-D) and complex tandem gait (CTG) assessments pre- and post-season while wearing a functional near-infrared spectroscopy (fNIRS) sensor. The average head impact load (AHIL) for each athlete-season was determined via a standardised protocol of video-verification of headband-based head impact sensor data. Linear mixed effect models were used to determine the effects of AHIL and task condition (3 K-D cards or 4 CTG conditions) on the change in mean prefrontal cortical activation measured by fNIRS, and performance on K-D and CTG, from pre- to post-season. Although there was no difference in the pre- to post-season change in K-D or CTG performance, greater AHIL was associated with greater cortical activation at post-season in comparison to pre-season during the most challenging conditions of K-D ( p  = 0.003) and CTG ( p  = 0.02), suggesting that greater RHIE necessitates increased cortical activation to complete the more challenging aspects of these assessments at the same level of performance. These results describe the effect of RHIE on neurofunction and suggest the need for further study of the time course of these effects.

Current debate exists regarding the need for protective headwear in female lacrosse. To inform this issue, the current study quantified head impact exposure, mechanisms and kinematics in female lacrosse using instrumented mouthguards. A female high school varsity lacrosse team of 17 players wore the Stanford Instrumented Mouthguard (MiG) during 14 competitive games. Video footage was reviewed to remove false-positive recordings and verify head impacts, which resulted in a rate of 0.32 head impacts per athlete-exposure. Of the 31 video-confirmed head impacts, 54.8% were identified as stick contacts, 38.7% were player contacts and 6.5% were falls. Stick contacts had the greatest peak head kinematics. The most common impact site was the side of the head (35.5%), followed by the face/jaw (25.8%), forehead (6.5%), and crown (6.5%). Impacts to the face/jaw region of the head had significantly (p < 0.05) greater peak kinematics compared to other regions of the head, which may have resulted from the interaction of the impacting surface, or the lower jaw, and the sensor. The current study provides initial data regarding the frequency, magnitude and site of impacts sustained in female high school lacrosse. A larger sample size of high quality head impact data in female lacrosse is required to confirm these findings.

Auditory and visually evoked potentials (EP) have the ability to monitor cognitive changes after concussion. In the literature, decreases in EP are commonly reported; however, a subset of studies shows increased cortical activity after injury. We studied auditory and visual EP in 4-week-old female Yorkshire piglets (N = 35) divided into anesthetized sham, and animals subject to single (sRNR) and repeated (rRNR) rapid non-impact head rotations (RNR) in the sagittal direction. Two-tone auditory oddball tasks and a simple white-light visual stimulus were evaluated in piglets pre-injury, and at days 1, 4- and 7 post injury using a 32-electrode net. Traditional EP indices (N1, P2 amplitudes and latencies) were extracted, and a piglet model was used to source-localize the data to estimate brain regions related to auditory and visual processing. In comparison to each group's pre-injury baselines, auditory Eps and brain activity (but not visual activity) were decreased in sham. In contrast, sRNR had increases in N1 and P2 amplitudes from both stimuli. The rRNR group had decreased visual N1 amplitudes but faster visual P2 latencies. Auditory and visual EPs have different change trajectories after sRNR and rRNR, suggesting that injury biomechanics are an important factor to delineate neurofunctional deficits after concussion.

Background: A visio-vestibular home exercise program (VV-HEP) can provide an equitable and cost-effective method for therapy targeted towards visio-vestibular deficits that are common following concussion. The effects of a VV-HEP on improving concussion symptoms and visio-vestibular function are unclear., Purpose: Determine the effect of VV-HEP on symptoms and visio-vestibular function in concussed pediatric patients., Methods: This study included 527 patients [294 female (55.8%); age = 14.4 ± 2.1 years] reporting to a specialty care concussion center within 28 days of injury and for a first follow-up within 60 days of injury. Patients completed the Post-Concussion Symptom Inventory (PCSI) and Visio-Vestibular Examination (VVE). Patients were prescribed the VV-HEP at initial visit, with exercises including saccades, gaze stability, convergence, and balance, and instructed to complete these 1-2 times/day. At follow-up, patients self-reported their VV-HEP progress as (1) has not done, (2) in progress, or (3) completed. Primary outcomes included VV-HEP progress at follow-up, PCSI endorsement and severity, VVE subtests (normal/abnormal), and total VVE score (abnormal = 2 + abnormal subtests). Kruskal-Wallis tests and chi-square were used to determine if concussion symptoms or the proportion of abnormal VVE outcomes, respectively, were associated with VV-HEP status. Post-hoc pairwise comparisons with Bonferonni corrections were used to determine concussion symptom ( α  = 0.017 a priori ) and VVE ( α  = 0.005 a priori ) differences in VV-HEP status., Results: At follow-up, patients who had completed the VV-HEP reported lower symptom endorsement (median = 1, IQR = 0-3) and lower symptom severity (median = 1, IQR = 0-4) relative to patients who had not started the VV-HEP (endorsement median = 7, IQR = 1-13, p  < 0.0001; severity median = 15.5, IQR = 2-32.5, p  < 0.0001) and those in progress (endorsement median = 8, IQR = 3-14, p  < 0.0001; severity median = 15, IQR = 4-30, p  < 0.0001). A lower proportion of patients who completed the VV-HEP reported with abnormal vestibular-ocular reflex (22.2%), tandem gait (0%), and total VVE score (22.2%) relative to those who had not started or those in progress ( p  < 0.005)., Conclusion: Our findings indicate that patients who completed the VV-HEP had lower symptom burden and improved visio-vestibular function relative to those who did not start or were in progress. This suggests that a VV-HEP can effectively reduce visio-vestibular dysfunction following concussion and may serve as a means to minimize inequities in access to care., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Roby, Podolak, Grady, Arbogast and Master.)

Background: Few studies have examined psychiatric symptoms during the acute phase following a concussion in adolescents. Thus, this study compares anxiety and depression in acutely concussed and nonconcussed adolescents., Hypothesis: Acutely concussed adolescents will report greater anxiety and depressive symptoms compared with nonconcussed adolescents., Study Design: Prospective cohort study., Level of Evidence: Level 3., Methods: Data were collected from 282 adolescents (111 concussed within 28 days of injury, 171 nonconcussed), 13 to 18 years of age, who completed Patient-Reported Outcome Measurement Information System (PROMIS) Anxiety and Depressive Symptoms measures. We calculated average T-scores for anxiety and depression across both groups and compared the proportion of those who scored above normal limits. Finally, we calculated risk ratios for anxiety and depression scores above normal limits., Results: Average T-scores for anxiety did not differ in concussed versus nonconcussed adolescents (mean: 45.9 [SD 10.84] vs 45.2 [8.1], respectively, P = 0.54), whereas average T-scores for depression were significantly higher in concussed versus nonconcussed adolescents (46.0 [10.88] vs 42.8 [8.48], respectively, P < 0.01). The proportion of concussed adolescents above normal limits for depression was greater than nonconcussed adolescents (32.4% vs 20.5%, respectively, P = 0.02). Post hoc sensitivity analyses excluding those with a history of anxiety or depression demonstrated a 1.45 (95% CI, 0.97, 2.01) and 1.56 (95% CI, 0.95, 2.56) increased risk of an above-normal anxiety and depression score for concussed compared with nonconcussed adolescents, respectively, although both were nonsignificant., Conclusion: Although we found few significant differences between the 2 groups, the results highlight that many concussed adolescents met the threshold for above-average symptoms on the depression and anxiety PROMIS measures., Clinical Relevance: In adolescents, there is increased risk for psychiatric sequalae in the acute period after a concussion. As such, we suggest that clinicians consider incorporating depression screening when caring for adolescents after a concussion.

Objective: To characterize the relationship of sociodemographic factors to adherence to provider recommendations for pediatric concussion., Setting: Primary care (PC) practices within the Children's Hospital of Philadelphia network., Participants: Patients aged 5 to 18 years old who presented to any PC site for concussion from September 26, 2019, to December 31, 2019., Design: Retrospective medical record review., Main Measures: The primary outcome was adherence to follow-up recommendations as defined by (1) continued follow-up until provider clearance to return to full activity; (2) no more than 2 no-show visits; and (3) for those referred to specialty care (SC), attending at least 1 visit. We compared adherence by race/ethnicity, insurance, age, sex, injury mechanism, and repeat head injury using bivariate and multivariate analyses. A secondary outcome of referral to SC was compared by sociodemographic factors., Results: A total of 755 patients were included. Overall, 80.5% of the patients met adherence criteria. Following adjustment, non-Hispanic Black patients and publicly insured/self-pay patients were less likely to adhere to recommendations than non-Hispanic White patients (adjusted odds ratio [AOR] = 0.60; 95% CI, 0.37-1.00) and privately insured patients (AOR = 0.48; 95% CI, 0.30-0.75), respectively. When assessing differences in referral to SC, non-Hispanic Black patients and publicly insured/self-pay patients were more likely to receive a referral than their non-Hispanic White peers (OR = 1.56; 95% CI, 1.00-2.45) and privately insured patients (OR = 1.56; 95% CI, 1.05-2.32), respectively., Conclusion: This study highlights disparities in adherence to concussion care recommendations, with non-Hispanic Black and publicly insured/self-pay patients less likely to adhere to follow-up recommendations than non-Hispanic White and privately insured patients, respectively. These disparities may impact recovery trajectories. Future studies should aim to identify specific individual- and system-level barriers preventing adherence to care in order to ultimately inform targeted interventions to achieve equity in care delivery and outcomes., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Neurological disorders and traumatic brain injury (TBI) are among the leading causes of death and disability. The pupillary light reflex (PLR) is an emerging diagnostic tool for concussion in humans. We compared PLR obtained with a commercially available pupillometer in the 4 week old piglet model of the adolescent brain subject to rapid nonimpact head rotation (RNR), and in human adolescents with and without sports-related concussion (SRC). The 95% PLR reference ranges (RR, for maximum and minimum pupil diameter, latency, and average and peak constriction velocities) were established in healthy piglets (N = 13), and response reliability was validated in nine additional healthy piglets. PLR assessments were obtained in female piglets allocated to anesthetized sham (N = 10), single (sRNR, N = 13), and repeated (rRNR, N = 14) sagittal low-velocity RNR at pre-injury, as well as days 1, 4, and 7 post injury, and evaluated against RRs. In parallel, we established human PLR RRs in healthy adolescents (both sexes, N = 167) and compared healthy PLR to values obtained <28 days from a SRC (N = 177). In piglets, maximum and minimum diameter deficits were greater in rRNR than sRNR. Alterations peaked on day 1 post sRNR and rRNR, and remained altered at day 4 and 7. In SRC adolescents, the proportion of adolescents within the RR was significantly lower for maximum pupil diameter only (85.8%). We show that PLR deficits may persist in humans and piglets after low-velocity head rotations. Differences in timing of assessment after injury, developmental response to injury, and the number and magnitude of impacts may contribute to the differences observed between species. We conclude that PLR is a feasible, quantifiable involuntary physiological metric of neurological dysfunction in pigs, as well as humans. Healthy PLR porcine and human reference ranges established can be used for neurofunctional assessments after TBI or hypoxic exposures (e.g., stroke, apnea, or cardiac arrest).

Objective: To evaluate pre - to post-season differences in individual subtests of the Visio-Vestibular Examination (VVE) in healthy middle and high school athletes., Methods: This prospective cohort study recruited participants from a private suburban United States secondary school. Participants completed a demographic questionnaire prior to the start of their season. A proxy for head impact exposure was estimated by incorporating previously published head impact frequencies by team and sport. The VVE was completed pre - and post-season and consisted of 9 subtests: smooth pursuit, horizontal/vertical saccades and gaze stability, binocular convergence, left/right monocular accommodation, and complex tandem gait. Generalized estimating equations were employed to assess the relative risk of an abnormal VVE outcome based on testing session (pre - vs. post-season)., Results: Participants included middle and high school athletes (n = 115; female = 59 (51.3%); median age at first assessment = 14.9 years, [IQR = 13.6, 16.0]) during 2017/18 - 2019/20 school years. During pre-season testing, accommodation (10.0%) and complex tandem gait (9.2%) had the largest proportion of abnormal outcomes, while smooth pursuits (10.6%) and convergence (9.5%) had the largest proportion of abnormal outcomes post-season. When assessing the effect of testing session on the relative risk of any abnormal VVE subtest, there were no significant findings (P ≥ 0.25). Additionally, there were no significant effects of testing session when adjusting for estimated head impact exposure for any VVE subtest (P ≥ 0.25)., Conclusions: Visio-vestibular function as measured by the VVE does not change from pre - to post-season in otherwise healthy adolescent athletes. Our findings suggest that the VVE may be stable and robust to typical neurodevelopment occurring in this dynamic age group and help inform post-injury interpretation of visio-vestibular impairments.

The use of head kinematic measurement devices has recently proliferated owing to technology advances that make such measurement more feasible. In parallel, demand to understand the biomechanics of head impacts and injury in sports and the military has increased as the burden of such loading on the brain has received focused attention. As a result, the field has matured to the point of needing methodological guidelines to improve the rigor and consistency of research and reduce the risk of scientific bias. To this end, a diverse group of scientists undertook a comprehensive effort to define current best practices in head kinematic measurement, culminating in a series of manuscripts outlining consensus methodologies and companion summary statements. Summary statements were discussed, revised, and voted upon at the Consensus Head Acceleration Measurement Practices (CHAMP) Conference in March 2022. This manuscript summarizes the motivation and methods of the consensus process and introduces recommended reporting checklists to be used to increase transparency and rigor of future experimental design and publication of work in this field. The checklists provide an accessible means for researchers to apply the best practices summarized in the companion manuscripts when reporting studies utilizing head kinematic measurement in sport and military settings., (© 2022. The Author(s).)

Seating configurations for autonomous driving will include reclined front seated occupants, which may expose child occupants seated directly behind to head impacts even in pre-crash scenarios. This study used mathematical modelling to investigate head contact for second-row child occupants seated behind a reclined front-seat during an automatic emergency braking (AEB) scenario. Although characterized by low speed (<1 m/s), head contacts were observed for a seatbelt-restrained 10-year-old and a 6-year-old in a low-back booster when the front-seat was reclined and in an aftward track position. Future seating configurations should consider the potential for head contact by second-row child occupants during crash-avoidance scenarios.

Visual and vestibular deficits, as measured by a visio-vestibular examination (VVE), are markers of concussion in youth. Little is known about VVE evolution post-injury, nor influence of age or sex on trajectory. The objective was to describe the time trend of abnormal VVE elements after concussion. Two cohorts, 11-18 years, were enrolled: healthy adolescents ( n  = 171) from a high school with VVE assessment before or immediately after their sport seasons and concussed participants ( n  = 255) from a specialty care concussion program, with initial assessment ≤28 days from injury and VVE repeated throughout recovery during clinical visits. The primary outcome, compared between groups, is the time course of recovery of the VVE examination, defined as the probability of an abnormal VVE (≥2/9 abnormal elements) and modeled as a cubic polynomial of days after injury. We explored whether probability trajectories differed by: age (<14 years vs. 14+ years), sex, concussion history (0 versus 1+), and days from injury to last assessment (≤28 days vs. 29+ days). Overall, abnormal VVE probability peaked at 0.57 at day 8 post-injury, compared with an underlying prevalence of 0.083 for uninjured adolescents. Abnormal VVE probability peaked higher for those 14+ years, female, with a concussion history and whose recovery course was longer than 28 days post-injury, compared with their appropriate strata subgroups. Females and those <14 years demonstrated slower resolution of VVE abnormalities. VVE deficits are common in adolescents after concussion, and the trajectory of resolution varies by age, sex, and concussion history. These data provide insight to clinicians managing concussions on the timing of deficit resolution after injury.

Objectives: The aim of this study was to compare demographic characteristics, medical care, and outcomes among patients with assault-related concussion (ARC) versus sports and recreation-related concussion (SRC)., Methods: We conducted a retrospective chart review of 124 patients (62 ARC, 62 SRC) aged 8 to 17 years presenting to the care network of a large tertiary care pediatric hospital between July 1, 2012, and June 30, 2014 with a concussion diagnosis at time of presentation. We abstracted patient demographics, initial medical care visit characteristics, and outcome data, and compared proportions using χ2 testing and Fisher exact test and medians using Wilcoxon rank sum test., Results: Patients with ARC were more likely to be Black, publicly insured, and present first for care to the emergency department. Significantly fewer patients with ARC received visio-vestibular testing at initial visit (27% vs 74%, P < 0.001). During recovery, the total number of reported physical, cognitive, emotional, and sleep symptoms did not differ between groups; however, more than twice as many patients with ARC reported decline in grades postinjury compared with patients with SRC (47% vs 20%, P = 0.012). There were trends toward prolonged symptom recovery and time to physician clearance for full return to activities among patients with ARC compared with SRC., Conclusions: This study highlights potential disparities in the initial evaluation and outcomes of pediatric concussion patients based on mechanism of injury. Patients with ARC were less likely to receive a concussion-specific diagnostic evaluation and reported a greater impact on educational outcomes, suggesting differences in concussion diagnosis and management among assault-injured patients. Further examination in larger populations with prospective studies is needed to address potential inequities in concussion care and outcomes among patients with ARC., Competing Interests: Disclosure: The author declares no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: To assess if abnormalities on visio-vestibular examination (VVE) are associated with concussion history (first vs. repeat) or age of first concussion in acutely concussed adolescents., Design: Cross-sectional., Methods: Data were queried from the Children's Hospital of Philadelphia Minds Matter concussion registry. Patients aged 14-18 years old presenting for their initial visit to the specialty care concussion program within 28 days of injury were included. Demographics, including age, sex, concussion history, and age of first concussion, were collected before the exam. The VVE consisted of 9 subtests: smooth pursuit, horizontal/vertical saccades and vestibulo-ocular reflex (VOR), binocular convergence, left/right monocular accommodation, and complex tandem gait. Primary outcomes included VVE subtests (normal/abnormal), and total VVE score (abnormal = 2+ abnormal subtests)., Results: Among 1051 patients included (female = 604(57.5 %); age = 15.6 ± 1.2; median lifetime concussions = 1 [IQR = 1,3]), 518 had repeat concussion. Controlling for age and sex, first vs. repeat concussion was not associated with any VVE subtest or total score (Total VVE Score RR = 1.35, 99.5%CI = 0.70,2.61). Of those with repeat concussion, 190 had valid age of first concussion data. Controlling for age, sex, and number of lifetime concussions, age of first concussion was not significantly associated with any VVE subtest or total score (Total VVE Score RR = 1.11, 99.5%CI = 0.78,1.57)., Conclusions: Adolescents with concussion history present with similar visio-vestibular function to those with no concussion history. Additionally, clinical effects of early age of first concussion may not be evident in children. This study provides foundational data regarding potential cumulative effects of concussion in younger athletes., (Copyright © 2022 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Significance: Eye tracking assessments that include pupil metrics can supplement current clinical assessments of vision and autonomic dysfunction in concussed adolescents., Purpose: This study aimed to explore the utility of a 220-second eye tracking assessment in distinguishing eye position, saccadic movement, and pupillary dynamics among uninjured adolescents, those with acute post-concussion symptoms (≤28 days since concussion), or those with persistent post-concussion symptoms (>28 days since concussion)., Methods: Two hundred fifty-six eye tracking metrics across a prospective observational cohort of 180 uninjured adolescents recruited from a private suburban high school and 224 concussed adolescents, with acute or persistent symptoms, recruited from a tertiary care subspecialty concussion care program, 13 to 17 years old, from August 2017 to June 2021 were compared. Kruskal-Wallis tests were used, and Bonferroni corrections were applied to account for multiple comparisons and constructed receiver operating characteristic curves. Principal components analysis and regression models were applied to determine whether eye tracking metrics can augment clinical and demographic information in differentiating uninjured controls from concussed adolescents., Results: Two metrics of eye position were worse in those with concussion than uninjured adolescents, and only one metric was significantly different between acute cases and persistent cases. Concussed adolescents had larger left and right mean, median, minimum, and maximum pupil size than uninjured controls. Concussed adolescents had greater differences in mean, median, and variance of left and right pupil size. Twelve metrics distinguished female concussed participants from uninjured; only four were associated with concussion status in males. A logistic regression model including clinical and demographics data and transformed eye tracking metrics performed better in predicting concussion status than clinical and demographics data alone., Conclusions: Objective eye tracking technology is capable of quickly identifying vision and pupillary disturbances after concussion, augmenting traditional clinical concussion assessments. These metrics may add to existing clinical practice for monitoring recovery in a heterogeneous adolescent concussion population., Competing Interests: Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest., (Copyright © 2022 American Academy of Optometry.)

Objective: To determine the relationship between patient characteristics and performance on the visio-vestibular examination (VVE) in a cohort of healthy youth athletes and explore the potential association between the VVE and other standardized concussion batteries., Design: Cross-sectional., Setting: Suburban middle and high school., Patients: One hundred ninety subjects age 11 to 18 enrolled before their respective scholastic sport season between August 2017 and March 2020., Assessment of Independent Variables: Patient age, sex, concussion history, comorbidities, hours of weekly exercise, Sport Concussion Assessment Tool, 5th edition (SCAT-5), King-Devick (K-D), Postconcussion Symptom Inventory (PCSI)., Main Outcome Measures: Visio-vestibular examination abnormalities (smooth pursuit, horizontal and vertical saccades, horizontal and vertical gaze stability, convergence, right and left monocular accommodation, complex tandem gait)., Results: Overall, 29.5% of subjects had at least one of 9 VVE elements abnormal, 7.9% at least 2, and 3.2% at least 3. None of 72 comparisons of the VVE elements, when stratified by age, sex, concussion history, history of headaches, attention deficit hyperactivity disorder, learning issues, psychiatric problems, motion sickness, or weekly hours of exercise, reached significance using the Benjamini-Hochberg procedure at a false discovery rate of 5%. There were no significant associations between VVE elements and the SCAT-5, K-D, or PCSI., Conclusions: The VVE is robust across multiple patient characteristics. Although healthy subjects may have one abnormal element, multiple abnormal elements are a less common feature, making multiple abnormal elements more indicative of concussion, highlighting the use of this assessment in the setting of injury. The VVE tests unique domains when compared with the PCSI, SCAT-5, and K-D., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Increased sensitivity to light is common after concussion. Viewing a flickering light can also produce uncomfortable somatic sensations like nausea or headache. We examined effects evoked by viewing a patterned, flickering screen in a cohort of 81 uninjured youth athletes and 84 concussed youth. We used Multiple correspondence analysis and identified two primary dimensions of variation: the presence or absence of visually evoked effects and variation in the tendency to manifest effects that localized to the eyes (e.g., eye watering) versus more generalized neurological effects (e.g., headache). Based on these two primary dimensions, we grouped participants into three categories of evoked symptomatology: no effects, eye-predominant effects, and brain-predominant effects. A similar proportion of participants reported eye-predominant effects in the uninjured (33.3%) and concussed (32.1%) groups. By contrast, participants who experienced brain-predominant effects were almost entirely from the concussed group (1.2% of uninjured, 35.7% of concussed). The presence of brain-predominant effects was associated with a higher concussion symptom burden and reduced performance on visio-vestibular tasks. Our findings indicate that the experience of negative constitutional, somatic sensations in response to a dynamic visual stimulus is a salient marker of concussion and is indicative of more severe concussion symptomatology. We speculate that differences in visually evoked effects reflect varying levels of activation of the trigeminal nociceptive system.

Objective: To evaluate the discriminatory ability of different repetition increments of saccades and gaze stability testing for diagnosing concussion in adolescents., Design: Cross-sectional., Setting: Suburban high school and academic pediatric tertiary care center., Participants: Sixty-nine adolescent athletes within 28 days of a sports- or recreation-related concussion and 69 adolescent athletes without recent concussion., Assessment of Independent Variables: Symptom provocation with horizontal and vertical saccades and gaze stability testing performed up to 30 repetitions., Main Outcome Measures: Sensitivity and specificity at 10-repetition increments (≤10, ≤20, ≤30) and area under the receiver operating characteristic curves (AUC) of a visio-vestibular examination (VVE) subscore, scored 0 to 4 based on the number of assessments with symptom provocation, at each repetition increment., Results: Sensitivity improved when increasing from ≤10 to ≤20 to ≤30 repetitions for horizontal (25% to 50% to 69%) and vertical (32% to 52% to 74%) saccades and horizontal (19% to 45% to 71%) and vertical (23% to 45% to 72%) gaze stability. Specificity was comparable at ≤10 and ≤20 repetitions, but decreased at ≤30 repetitions across assessments. For a VVE subscore (0-4) based on the number of symptomatic assessments, the discriminatory ability of the test was highest at ≤20 repetitions (AUC of 0.79) with an optimal subscore of one (sensitivity 59%, specificity 96%)., Conclusions: A VVE including a higher threshold level of repetitions for saccades and gaze stability has improved discriminatory ability for concussion, with an optimized AUC of 0.79 at ≤20 repetitions., Clinical Relevance: The findings in this study suggest that a higher threshold level of repetitions of 2 commonly used visio-vestibular assessments enables clinicians to more accurately diagnose youth concussion., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: Ergonomic design of child restraint systems (CRS) may facilitate optimal travel behavior and crash protection of child passengers during motor vehicle trips. However there have been few studies examining the relationship between CRS design and child passenger travel behavior. The aim of this study was to examine whether associations between CRS design features and child passenger behavior exist during real-world, everyday vehicle trips., Methods: Video from a naturalistic driving study (NDS) was analyzed in this study. Families drove an instrumented study vehicle for approximately two weeks with at least one child aged between one and eight years traveling in their own forward-facing (FF) CRS or belt positioning booster (BPB). Video for one child passenger was randomly selected from each trip for analysis. Video was coded for five-second epochs at nine time points (5%, 17%, 25%, 30%, 50%, 53%, 75%, 89% and 95% of trip length). Two types of child passenger travel behaviors were identified by manual review of the video and audio recordings: (i) optimal/suboptimal head position and (ii) correct/incorrect use of the internal harness/shoulder belt. Video screenshots were used to characterize CRS design features. Random effects logistic regression models were used to examine the associations between specific CRS design features and the travel behaviors of interest, whilst accounting for clustering of data by child and trip., Results: Suboptimal head position was associated with the absence of a height adjustable headrest and a narrow headrest wing width in FFCRS. Incorrect harness use in a FFCRS was associated with the absence of an adjustable headrest, in addition to headrest features such as wing width and depth. In BPBs, a reduction in suboptimal head position was associated with the absence of a sash belt guide, however no restraint design features were associated with incorrect shoulder belt use., Conclusions: Some CRS design features may influence undesirable child passenger travel behavior. These early findings support enhanced and user-centric CRS design as a likely important mechanism to improve child passenger safety.

Objectives: To examine sex differences in sport-related concussion (SRC) across comparable sports., Methods: Prospective cohort of collegiate athletes enrolled between 2014 and 2017 in the Concussion Assessment, Research and Education Consortium study., Results: Among 1071 concussions (females=615; 57.4%), there was no difference in recovery (median days to full return to play) (females=13.5 (IQR 9.0, 23.1) vs males=11.8 (IQR 8.1, 19.0), p=0.96). In subgroup analyses, female recovery was longer in contact (females=12.7 days (IQR 8.8, 21.4) vs males=11.0 days (IQR 7.9, 16.2), p=0.0021), while male recovery was longer in limited contact sports (males=16.9 days (IQR 9.7, 101.7) vs females=13.8 days (IQR 9.1, 22.0), p<0.0001). There was no overall difference in recovery among Division I schools (females=13.7 (IQR 9.0, 23.1) vs males=12.2 (IQR 8.2 19.7), p=0.5), but females had longer recovery at the Division II/III levels (females=13.0 (IQR 9.2, 22.7) vs males=10.6 (IQR 8.1, 13.9), p=0.0048)., Conclusion: Overall, no difference in recovery between sexes across comparable women's and men's sports in this collegiate cohort was found. However, females in contact and males in limited contact sports experienced longer recovery times, while females had longer recovery times at the Division II/III level. These disparate outcomes indicate that, while intrinsic biological sex differences in concussion recovery may exist, important, modifiable extrinsic factors may play a role in concussion outcomes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Field studies have evaluated the accuracy of sensors to measure head impact exposure using video analysis, but few have studied false negatives. Therefore, the aim of the current study was to investigate the proportion of potential false negatives in high school soccer head impact data. High school athletes (23 females and 31 males) wore headband-mounted Smart Impact Monitor-G impact sensors during competitive soccer games. Video footage from 41 varsity games was analyzed by 2 independent reviewers to identify head contact events, which were defined as visually observed contact to the head. Of the 1991 video-identified head contact events for which sensors were functioning and worn by the players, 1094 (55%) were recorded by the sensors. For female players, 45% of video-identified head contact events were recorded by the sensor compared with 59% for male players. For both females and males, sensitivity varied by impact mechanism. By quantifying the proportion of potential false negatives, the sensitivity of a sensor can be characterized, which can inform the interpretation of previous studies and the design of future studies using head impact sensors. Owing to the difficulty in obtaining ground truth labels of head impacts, video review should be considered a complementary tool to head impact sensors.

Objective: The aim of the study was to comprehensively describe the natural history of concussion in early childhood between 0 and 4 years., Methods: Retrospective cohort study of 329 patients aged 0 to 4 years, with an International Classification of Diseases, Ninth Revision, concussion diagnosis in the Children's Hospital of Philadelphia healthcare network from October 1, 2013, to September 30, 2015. Clinical data were abstracted from the Children's Hospital of Philadelphia electronic health record, which captured all clinical care visits and injury characteristics., Results: Nearly 9 (86.6%) of 10 patients sought care in the emergency department or urgent care setting, most commonly on the day of injury (56.2%) and as a result of a fall (64.4%). More than two-thirds (64.4%) of patients or their parent/caregiver reported somatic symptoms (ie, vomiting or headache), whereas close to half (49.2%) reported sleep issues. One of 5 patients identified emotional symptoms (21.9%) or visio-vestibular dysfunction (20.4%). Many patients also experienced symptoms not included in standard assessment tools including personality changes (34.0%) and change in appetite (12.8%)., Conclusions: These results provide insight into the clinical characteristics of concussion in early childhood up to 4 years of age. Because assessment in this group relies heavily on parent/caregiver symptom reporting, rather than patient self-report, these results will aid clinicians with the challenge of diagnosing concussions in this population. These findings highlight the need to develop additional tools to adequately and systematically assess common signs and symptoms of concussion in early childhood that may not be included in standard assessment scales routinely used in older adolescents and adults., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Sport-related concussion is a public health problem, particularly in adolescents. Quality of life is reduced in adolescents with persistent post-concussive symptoms (symptoms >28 days). We replicated a previous randomised controlled trial to validate the safety, efficacy, and generalisability of, and objective adherence to, prescribed early targeted heart rate subsymptom threshold aerobic exercise compared with placebo-like stretching exercise for adolescent recovery from sport-related concussion and for reducing the risk of persistent post-concussive symptoms., Methods: This randomised controlled trial was done at three community and hospital-affiliated sports medicine concussion centres in the USA. Male and female adolescent athletes (aged 13-18 years) presenting within 10 days of sport-related concussion were randomly assigned to individualised subsymptom threshold aerobic or stretching exercise at least 20 min daily, for up to 4 weeks after injury. Exercise adherence and intensity were measured by heart rate monitors. The primary outcome was clinical recovery (ie, return to baseline symptoms, normal exercise tolerance, and a normal physical examination) within the 4-week intervention period, and development of persistent post-concussive symptoms beyond 28 days after injury. This study is registered with ClinicalTrials.gov, NCT02959216., Findings: Between Aug 1, 2018, and March 31, 2020, 118 adolescents were recruited (61 were randomly assigned to the aerobic exercise group and 57 to the stretching exercise group) and included in the intention-to-treat analysis. On survival analysis, controlling for sex, site, and mean daily exercise time, patients assigned to aerobic exercise were more likely to recover within 4 weeks after injury compared with those assigned to stretching exercise, with a 48% reduced risk of persistent post-concussive symptoms (hazard ratio for stretching vs aerobic exercise of 0·52 [95% CI 0·28-0·97], p=0·039). No adverse events were reported., Interpretation: This multicentre study found that early treatment with subsymptom threshold aerobic exercise safely speeds recovery from sport-related concussion and reduces the risk for persistent post-concussive symptoms, an important result given the impact of delayed recovery on adolescent quality of life. Adherence was good and there were no adverse events from this non-pharmacological treatment. These results suggest that physicians should not only permit, but consider prescribing, early subsymptom threshold physical activity to adolescents as treatment for sport-related concussion and to reduce the risk of persistent post-concussive symptoms., Funding: American Medical Society for Sports Medicine., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Previous studies of support legs in rearward-facing infant CRS models have focused on frontal impacts and have found that the presence of a support leg is associated with a reduction in head injury metrics. However, real-world crashes often involve an oblique principal direction of force. The current study used sled tests to evaluate the effectiveness of support legs in rearward-facing infant CRS models for frontal and frontal-oblique impacts with and without a simulated front row seatback. Frontal and frontal-oblique impact sled tests were conducted using the simulated Consumer Reports test method with and without the blocker plate, which was developed to represent a front row seatback. The Q1.5 anthropomorphic test device (ATD) was seated in rearward-facing infant CRS models, which were tested with and without support legs. The presence of a support leg was associated with significant reductions of head injury metrics below injury tolerance limits for all tests, which supports the findings of previous studies. The presence of a support leg was also associated with significant reductions of peak neck tensile force. The presence of the blocker plate resulted in greater head injury metrics compared to tests without the blocker plate, but the result was non-significant. However, the fidelity of the interaction between the CRS and blocker plate as an adequate representation of the interaction that would occur in a real vehicle is not well understood. The findings from the current study continue to support the benefit of support legs in managing the energy of impact for a child in a rearward-facing CRS.

Lower limb injury rate in the National Football League (NFL) is greater on synthetic turf than on natural turfgrass. Foot loading in potentially injurious situations can be mitigated by damage to natural turfgrass that limits the peak load by allowing relative motion between the foot and the ground. Synthetic turf surfaces do not typically sustain such damage and thus lack such a load-limiting mechanism. To guide innovation in synthetic turf design, this paper reports 1) the peak loads of natural turfgrass when loaded by a cleated footform and 2) corridors that define the load-displacement response. Kentucky bluegrass [Poa pratensis, L.] and two cultivars of hybrid bermudagrass [Cynodon dactylon (L.) Pers × C. transvaalensis Burtt Davy] were tested with two cleat patterns in three loading modes (anterior-posterior or AP translation, medial-lateral or ML translation, and forefoot external rotation) at two power levels (full-power, which generated potentially injurious loads, and reduced-power, which generated horizontal forces similar to non-injurious ground reaction forces applied by an elite athlete during play). All tests generated peak force<4.95 kN and torque<173 Nm, which is in a loading regime that would be expected to mitigate injury risk. In full-power tests, bermudagrass withstood significantly (p < 0.05) greater peak loads than Kentucky bluegrass: (3.86 ± 0.45 kN vs. 2.66 ± 0.23 kN in AP, 3.25 ± 0.45 kN vs. 2.49 ± 0.36 kN in ML, and 144.8 ± 12.0 Nm vs. 126.3 ± 6.1 Nm in rotation). Corridors are reported that describe the load-displacement response aggregated across all surfaces tested., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Instrumented mouthpieces (IM) offer a means of measuring head impacts that occur in sport. Direct measurement of angular head kinematics is preferential for accuracy; however, existing IMs measure angular velocity and differentiate the measurement to calculate angular acceleration, which can limit bandwidth and consume more power. This study presents the development and validation of an IM that uses new, low-power accelerometers for direct measurement of linear and angular acceleration over a broad range of head impact conditions in American football. IM sensor accuracy for measuring six-degree-of-freedom head kinematics was assessed using two helmeted headforms instrumented with a custom-fit IM and reference sensor instrumentation. Head impacts were performed at 10 locations and 6 speeds representative of the on-field conditions associated with injurious and non-injurious impacts in American football. Sensor measurements from the IM were highly correlated with those from the reference instrumentation located at the maxilla and skull center of gravity. Based on pooled data across headform and impact location, R 2 ≥ 0.94, mean absolute error (AE) ≤ 7%, and mean relative impact angle ≤ 11° for peak linear and angular acceleration and angular velocity while R 2 ≥ 0.90 and mean AE ≤ 7% for kinematic-based injury metrics used in helmet tests., (© 2021. Biomedical Engineering Society.)

The Guardian Cap NXT (GC NXT) and the ProTech Helmet Cap (ProTech) are commercially available aftermarket products designed to augment the energy attenuation characteristics of American football helmets. The ability of these helmet shell add-on products to mitigate the severity of impacts typically experienced by professional offensive and defensive linemen was evaluated for seven helmet models using two test series. In linear impactor tests, the GC NXT reduced head impact severity as measured by the head acceleration response metric (HARM) by 9% relative to the helmets only, while the ProTech reduced HARM by 5%. While both products significantly improved the performance of the football helmets tested overall, effects varied by impact condition and helmet model with the add-ons worsening helmet performance in some conditions. The GC NXT had a strong effect size (Cohen's d = 0.8) whereas the ProTech had a medium effect (Cohen's d = 0.5). A second study investigated add-on performance for helmet-to-helmet impacts with eccentric impact vectors and resulted in a mixture of increased and decreased HARM when either add-on was placed on one or both helmets. Estimated risk for serious neck injury with add-ons and without differed by less than 4% for these eccentric impacts., (© 2021. Biomedical Engineering Society.)

Purpose: Although return to learn, exercise, and sports have evidence-based guidelines, there is limited research investigating return to driving after concussion. The purpose was to characterize and compare adolescent driving behaviors after concussion., Methods: Using the Minds Matter Concussion Registry, we queried data of adolescents, aged 16-19 years, diagnosed with a concussion ≤28 days of injury and seen between January 31, 2017 and August 31, 2018 at the specialty care concussion program. Outcomes included patient report of: changes postinjury driving behaviors; Post-Concussion Symptom Inventory; return to school, and exercise and sports. Provider recommendations for return to school after initial clinical assessment were also examined. Descriptive statistics, analysis of covariance, and chi-square tests were performed., Results: Of the 332 drivers (46.1% female; mean age 17.5 years, 95% confidence interval [CI], 17.4-17.6), 46.9% had returned to driving since injury. Of those who returned to driving, 58.9% reported "Driving with No Changes." The Post-Concussion Symptom Inventory score was higher among "Driving with Changes" (48.7, 95% CI: 42.2-55.2) than "Driving with No Changes" (27.4, 95% CI: 22.3-32.5, p < .01) and "Has Not Driven Since Injury" (42.3, 95% CI: 38.4-46.3, p < .01). Among the 332 drivers, few had returned to exercise (15.4%) or organized sports (6.0%). Of those in school (n = 291), only 8.9% were provider recommended to return to full school days after clinical assessment., Conclusion: Many adolescents continued to drive after concussion, despite not yet having returned to exercise or sport. Nine of 10 were advised to return to school with accommodations to begin a gradual increase in cognitive activity, suggesting a gradual increase in driving may be justified., (Copyright © 2020 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Introduction: Repetitive head impacts in soccer have been linked to short-term neurophysiological deficits, and female soccer players have higher concussion rates than males. These findings have inspired investigation into gender differences in head impact exposure and how head impact rate contributes to the cumulative effect of head impact exposure on neurological outcomes. Various periods of exposure have been used to calculate head impact rates, including head impacts per season, game, and player-hour., Purpose: The aim of this study was to apply different methodological approaches to quantify and compare head impact rates by gender for two seasons of high school varsity soccer., Methods: Video review was used to confirm all events recorded by a headband-mounted impact sensor and calculate playing time for all players. Impact rates were calculated per athlete exposure (presence and participation) and per player-hour (scheduled game time, individual play time, and absolute time)., Results: Impact rates per athlete exposure ranged from 2.5 to 3.2 for males and from 1.4 to 1.6 for females, and impact rates per player-hour ranged from 2.7 to 3.8 for males and from 1.0 to 1.6 for females. The exposure calculation method significantly affected head impact rates; however, regardless of approach, the head impact rate for males was higher, up to threefold, than for females. Individual head impact exposure varied substantially within a team with one in five players experiencing no impacts., Conclusions: Overall, the gender differences found in this study indicate that males experience higher head impact exposure compared with females. Future studies are needed to understand potential clinical implications of variability in head impact exposure and reconcile higher female concussion rates with the reduced head impact rates presented herein., (Copyright © 2021 by the American College of Sports Medicine.)

Previous studies have investigated the head impact kinematics of purposeful heading in youth soccer; however, less than a third of all head injuries in youth soccer have been found to involve ball contact. The aim of the current study was to identity the head impact kinematics and exposure not associated with purposeful heading of the ball in male youth soccer. Headband-mounted sensors were used to monitor the head kinematics of male junior varsity and middle school teams during games. Video analysis of sensor-recorded events was used to code impact mechanism, surface and site. Junior varsity players had non-header impact rates of 0.28 per athlete-exposure (AE) and 0.37 per player-hour (PH), whereas middle school players had relatively lower non-header impact rates of 0.16 per AE and 0.25 per PH. Such impact rates fell within the large range of values reported by previous studies, which is likely affected by sensor type and recording trigger threshold. The most common non-header impact mechanism in junior varsity soccer was player contact, whereas ball-to-head was the most common non-header impact mechanism in middle school soccer. Non-header impacts for junior varsity players had median peak kinematics of 31.0 g and 17.4 rad/s. Non-header impacts for middle school players had median peak kinematics of 40.6 g and 16.2 rad/s. For non-header impacts, ball impacts to the rear of the head the highest peak kinematics recorded by the sensor. Such data provide targets for future efforts in injury prevention, such as officiating efforts to control player-to-player contact., Competing Interests: Conflicts of Interest: No author declares a conflict of interest.

Purpose: Peak amplitude and peak latency in the pattern reversal visual evoked potential (prVEP) vary with maturation. We considered that principal component analysis (PCA) may be used to describe age-related variation over the entire prVEP time course and provide a means of modeling and removing variation due to developmental age., Methods: PrVEP was recorded from 155 healthy subjects ages 11 to 19 years at two time points. We created a model of the prVEP by identifying principal components (PCs) that explained >95% of the variance in a "training" dataset of 40 subjects. We examined the ability of the PCs to explain variance in an age- and sex-matched "validation" dataset (n = 40) and calculated the intrasubject reliability of the PC coefficients between the two time points. We explored the effect of subject age and sex upon the PC coefficients., Results: Seven PCs accounted for 96.0% of the variability of the training dataset and 90.5% of the variability in the validation dataset with good within-subject reliability across time points (R > 0.7 for all PCs). The PCA model revealed narrowing and amplitude reduction of the P100 peak with maturation, and a broader and smaller P100 peak in male subjects compared to female subjects., Conclusions: PCA is a generalizable, reliable, and unbiased method of analyzing prVEP. The PCA model revealed changes across maturation and biological sex not fully described by standard peak analysis., Translational Relevance: We describe a novel application of PCA to characterize developmental changes of prVEP in youths that can be used to compare healthy and pathologic pediatric cohorts.