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Context: There is a well-established increased risk of lower-extremity (LE) musculoskeletal (MSK) injury following a sport-related concussion (SRC). Neuromuscular training programs improve biomechanics associated with LE MSK injury and reduce LE MSK injury incidence, but their relative effectiveness in athletes with history of SRC is unknown. The purpose of this study was to evaluate LE MSK injury incidence in female adolescent athletes with history of SRC following a neuromuscular training intervention. Design: Prospective case-control. Methods: Seventy-seven adolescent female athletes aged 12–18 years who participated in soccer, volleyball, or basketball were recruited from a single institutional sports medicine research and performance center to complete a 6-week neuromuscular training program prior to competitive athletic season. Group (Control, History of SRC) comparisons of athlete exposure and relative LE MSK injury risk and rates during the competitive athletic season were assessed. Results: Ten injuries were recorded by 9 athletes. Female athletes who reported history of SRC had increased injury risk (Risk Ratio 3.9, 95% CI, 1.1–13.8, P =.01) and increased injury rate (rate ratio 4.1, 95% CI, 1.1–15.8, P =.03) compared with female athletes without history of SRC. Conclusions: Female adolescent athletes with history of SRC showed a greater risk of LE MSK injury compared with athletes with no history of SRC. Future work is still needed to understand the underlying mechanisms associated with future LE MSK injury following SRC and interventions that ameliorate elevated injury risk. [ABSTRACT FROM AUTHOR]

Context: Dual-task (simultaneous cognitive–motor activities) assessments have been adapted into reliable and valid clinical concussion measures. However, abundant motor and cognitive variations leave researchers and clinicians uncertain about which combinations elicit the intended dual-task effect. Our objective was to examine differences between commonly employed dual-task motor and cognitive combinations among healthy, college-aged individuals. Design: Cross-sectional laboratory study. Methods: Twenty participants (age: 21.3 [2.4] y; height: 176.0 [9.1] cm; mass: 76.0 [16.4] kg; 20% with concussion history) completed 4 motor tasks (gait, tandem gait, single-leg balance, and tandem balance) under 5 cognitive conditions (single task, subtraction, month reversal, spelling backward, and visual Stroop) in a research laboratory. The motor performance outcomes were spatiotemporal variables for gait and tandem gait and center of pressure path length (in centimeters) for single-leg and tandem balance. Cognitive outcomes were response rate (responses/second) and cognitive accuracy. We used separate repeated-measures analyses of variance for each motor and cognitive outcome with post hoc Tukey t tests. Results: Gait velocity, gait stride length, and tandem gait velocity demonstrated significant cognitive–motor interactions (P's <.001) such that all dual-task conditions resulted in varyingly slower or shorter movement than single task. Conversely, single-leg balance (P =.627) and tandem balance (P =.434) center of pressure path length did not significantly differ among the dual-task cognitive conditions or relative to single task. Statistically significant cognitive–motor interactions were observed only for spelling backward accuracy (P =.004) and response rates for spelling backward, month reversal, and visual Stroop (P's <.001) such that worse accuracy, but faster response rates, occurred during motor tasks. Conclusions: Gait and tandem gait motor tasks accompanied with spelling backward or subtraction cognitive tasks demonstrated consistently strong dual-task effects and, therefore, may be the best suited for clinical and research use following concussion. [ABSTRACT FROM AUTHOR]

Context: Mindfulness interventions (yoga, meditation) in traumatic brain injury populations show promising improvements in injury outcomes. However, most studies include all injury severities and use in-person, general programming lacking accessibility and specificity to the nuance of concussion. Therefore, this study investigated the feasibility and preliminary effectiveness of an online, concussion-focused meditation intervention among young adults with a concussion history. Design: Unblinded, single-arm, pilot intervention. Methods: Fifteen young adults aged 18 to 30 with a concussion history within the past 5 years completed 10 to 20 minutes per day of online, guided meditations for 6 weeks. Feasibility was assessed using the Feasibility of Intervention Measure. Concussion symptoms were measured using the Rivermead Post-Concussion Symptom Questionnaire, perceived stress the Perceived Stress Scale-10, and mindfulness the Five Facet Mindfulness Questionnaire. Descriptive statistics described the study sample and determined intervention adherence and feasibility. Paired sample t tests were used to examine preintervention/postintervention changes in concussion symptoms, perceived stress, and mindfulness, with descriptive statistics further detailing significant t tests. Results: Fifteen participants were enrolled, and 12 completed the intervention. The majority completed 5+ days per week of the meditations, and Feasibility of Intervention Measure (17.4 [1.8]) scores indicated high feasibility. Concussion symptom severity significantly decreased after completing the meditation intervention (11.3 [10.3]) compared with before the intervention (24.5 [17.2]; t[11] = 3.0, P =.01). The number of concussion symptoms reported as worse than before their concussion significantly decreased after completing the meditation intervention (2.7 [3.9]) compared with before the intervention (8.0 [5.7]; t[11] = 3.7, P =.004). Postintervention, 83.33% (n = 10) reported lower concussion symptom severity, and 75.00% (n = 9) reported less concussion symptoms as a mild, moderate, or severe problem (ie, worse than before injury). Conclusions: Findings suggest positive adherence and feasibility of the meditation intervention, with the majority reporting concussion symptom improvement postintervention. Future research is necessary to expand these pilot findings into a large trial investigating concussion-specific meditation programming. [ABSTRACT FROM AUTHOR]

Context: Sports-related concussions are commonly occurring injuries as a result of sports and recreation that may cause alterations in brain functioning. It is important to be able to evaluate the impact of these injuries on function to manage the injury recovery and ensure recovery. Recent literature suggests the use of objective evaluation strategies in a multifaceted approach to evaluate and manage these injuries. It is important to understand the relationships between the assessments and how best to utilize each assessment. The purpose of this study was to investigate if relationships exist between measures of vestibular function at baseline in assessments that may be used following sports-related concussions. Additionally, a secondary purpose was to determine if self-reported symptoms were related to performance on the assessments. This study aimed to identify if these assessments measured independent functions of the vestibulo–ocular reflex or if some redundancy existed among the assessment strategies. Design: A cross-sectional study design was used in a cohort of collegiate athletes ages 18–24. Methods: Participants completed demographics questionnaires, the Post-Concussion Symptom Scale, Gaze Stabilization Test, and Concussion Balance Test. Spearman rho correlations were used to examine the relationships between the measures. Results: One hundred and thirty-five collegiate athletes (82 males and 53 females) were included, representative of 3 sports (cheerleading, soccer, and football) with a mean age of 19.77 (1.42) years old. There were weak to moderate, significant relationships between measures of Gaze Stabilization Test and Concussion Balance Test errors (r =.20–.31, P =.001–.03). Conclusions: The direction of these relationships indicated that greater Concussion Balance Test errors were associated with greater Gaze Stabilization Test performance. These relationships may be attributed to the difficulty created by the foam conditions and the integration of more complex sensory tasks required to maintain balance during the more difficult conditions. [ABSTRACT FROM AUTHOR]

Purpose: Concussion management is shifting away from a rest-is-best approach, as data now suggest that exercise-is-medicine for this mild brain injury. Despite this, we have limited data on habitual physical activity following concussion. Therefore, our objective was to quantify accelerometer-measured physical activity and sedentary time in children with concussion (within the first month of injury) and healthy controls. We hypothesized that children with concussion would be less active than their healthy peers. Methods: We performed a secondary analysis of prospectively collected accelerometer data. Our sample included children with concussion (n = 60, 31 females) and historical controls (n = 60) matched for age, sex, and season of accelerometer wear. Results: Children with concussion were significantly more sedentary than controls (mean difference [MD], 38.3 min/d, P =.006), and spent less time performing light physical activity (MD, −19.5 min/d, P =.008), moderate physical activity (MD, −9.8 min/d, P <.001), and vigorous physical activity (MD, −12.0 min/d, P <.001); these differences were observed from 8:00 AM to 9:00 PM. Sex-specific analyses identified that girls with concussion were less active and more sedentary than both boys with concussion (P =.010) and healthy girls (P <.010). Conclusion: There is an activity deficit observed within the first month of pediatric concussion. Physical activity guidelines should address this while considering sex effects. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Concussion rates are commonly reported in high school and National Collegiate Athletics Association (NCAA) sports. Given that participation in collegiate recreation is on the rise, institutions should examine concussion rates within their recreational programs. We, therefore, retrospectively examined a recreational department's injury reports establishing concussion rates across (n = 16) club and (n = 10) intramural sports at a public university in the southeastern United States from 2016 to 2019. One hundred and thirty-five concussions (club n = 56; intramural n = 79) were identified and constituted 12.4% of documented injuries (n = 1,088). The intramural concussion rate was 0.57 per 1,000 athletic exposures (AEs) and AE was greatest in outdoor soccer (0.99 per 1,000 AE). Therefore, our data suggests an increased incidence of concussions in intramurals compared to published rates in NCAA and high school sports. Collegiate recreational departments should consider these concussion rates when formulating risk management strategies. [ABSTRACT FROM AUTHOR]

Athletes' history of concussions is an important indicator of risk potential in organized sports. The purpose of this project was to explore differences by sport classification (contact vs. noncontact) and sex on concussion history among university club sports participants. This was a cross-sectional quality improvement study (n = 593). The outcomes were self-reported answers to: (1) How many times have you been diagnosed with a concussion? and (2) How many times have you had your "bell rung"/"dinged"? Multivariable logistic regression models examined the association of contact club sport participation and sex on the history of concussion and prior experience of having their bell rung. Models were adjusted for age, race, participation in multiple sports, and years of participation in sports, and years in college. When compared to those in non-contact club sports, the adjusted odds of reporting ever having a concussion were 2.29 times higher for those participating in contact club sports (OR = 2.29; 95% CI: 1.49, 3.53). In the model for having a bell rung, those participating in a contact sport had 1.90 times greater odds of reporting having their bell rung in the past compared to those in noncontact sports (OR = 1.90; 95% CI: 1.25, 2.88). Whereas males and females did not differ in their self-reported concussion history, females had significantly lower odds of reporting having their bell rung in the past than males (OR = 0.46; 95% CI: 0.30, 0.69). Female athletes have a higher reporting of concussion incidence than that of male athletes. The use of terminology and variance in slang versus medical terms has the potential to affect reporting outcomes. Reporting of concussion incidents has the potential to be influenced by the nature of sport culture and sport participation in contact versus noncontact sports. Club sport athletes could benefit from tailored education related to concussions based on these results. [ABSTRACT FROM AUTHOR]

While research advancements have substantially improved concussion management efforts, consideration for the psychological and social aspects of concussive injuries have remained largely absent from concussion protocols. The present study was undertaken to identify elite athletes' psychological and social needs during the recovery process. Elite athletes with a history of concussion and mental performance consultants who work with concussed elite athletes participated in focus group interviews to shed light on these needs. A thematic analysis of these focus groups revealed six psychological and social needs: acceptance, normality, confidence, self-efficacy, trust in relationships, and social support. These themes are framed within concussion literature to help initiate a conversation on how psychological and social needs should be addressed as part of multifaceted efforts to improve concussion recovery. [ABSTRACT FROM AUTHOR]

BACKGROUND/OBJECTIVE: Headgear designed to protect girls lacrosse athletes is widely available and permitted for voluntary use; however, it remains unknown how policies mandating headgear use may change the sport and, particularly regarding impacts during game-play. Therefore, this study compares the impact rates and game play characteristics of girls high school lacrosse in Florida which mandates headgear use (HM), with states having no headgear mandate (NHM). MATERIALS AND METHODS: Video from 189 randomly-selected games (HM: 64, NHM: 125) were analyzed. Descriptive statistics, Impact Rates (IR), Impact Rate Ratios (IRR), Impact Proportion Ratios (IPR), and 95% Confidence Intervals (CI) were calculated. IRRs and IPRs with corresponding CIs that excluded 1.00 were deemed statistically significant. RESULTS: 16,340 impacts (HM:5,821 NHM: 10,519; 86.6 impacts/game, CI: 88.6-93.3) were identified using the Lacrosse Incident Analysis Instrument (LIAI). Most impacts directly struck the body (n = 16,010, 98%). A minority of impacts directly struck a players head (n = 330, 2%). The rate of head impacts was significantly higher in the HM cohort than NHM cohort (IRR = 2.1; 95% CI = 1.7-2.6). Most head impacts (n = 271, 82%) were caused by stick contact in both groups. There was no difference in the proportion of penalties administered for head impacts caused by stick contact between the HM and NHM cohorts (IPR IRRHM/NHM = 0.98; CI = 0.79-1.16). However, there was a significantly greater proportion of head impacts caused by player contact that resulted in a penalty administered in the HM cohort (IPR = 1.44 CI = 1.17-1.54). CONCLUSION: These findings demonstrate that mandating headgear use was associated with a two-fold greater likelihood of sustaining a head impact during game play compared to NHM states. A majority of head impacts in both HM and NHM states were caused by illegal stick contact that did not result in penalty.

Abstract This study compared findings from whole-brain diffusion tensor imaging (DTI) and volumetric magnetic resonance imaging (MRI) among 90 Active Duty Service Members with chronic mild traumatic brain injury (TBI; n = 52), chronic moderate-to-severe TBI (n = 17), and TBI-negative controls (n = 21). Data were collected on a Philips Ingenia 3T MRI with DTI in 32 directions. Results demonstrated that history of TBI was associated with differences in white matter microstructure, white matter volume, and cortical thickness in both mild TBI and moderate-to-severe TBI groups relative to controls. However, the presence, pattern, and distribution of these findings varied substantially depending on the injury severity. Spatially-defined forms of DTI fractional anisotropy (FA) analyses identified altered white matter organization within the chronic moderate-to-severe TBI group, but they did not provide clear evidence of abnormalities within the chronic mild TBI group. In contrast, DTI FA pothole analyses identified widely distributed areas of decreased FA throughout the white matter in both the chronic mild TBI and chronic moderate-to-severe TBI groups. Additionally, decreased white matter volume was found in several brain regions for the chronic moderate-to-severe TBI group compared with the other groups. Greater number of DTI FA potholes and reduced cortical thickness were also related to greater severity of self-reported symptoms. In sum, this study expands upon a growing body of literature using advanced imaging techniques to identify potential effects of brain injury in military Service Members. These findings may differ from work in other TBI populations due to varying mechanisms and frequency of injury, as well as a potentially higher level of functioning in the current sample related to the ability to maintain continued Active Duty status after injury. In conclusion, this study provides DTI and volumetric MRI findings across the spectrum of TBI severity. These results provide support for the use of DTI and volumetric MRI to identify differences in white matter microstructure and volume related to TBI. In particular, DTI FA pothole analysis may provide greater sensitivity for detecting subtle forms of white matter injury than conventional DTI FA analyses.

The Center for Disease Control and Prevention estimates that 75% of reported cases of traumatic brain injury (TBI) are mild, where chronic pain and depression are 2 of the most common symptoms. In this study, we used a murine model of repeated mild TBI to characterize the associated pain hypersensitivity and affective-like behavior and to what extent microglial reactivity contributes to these behavioral phenotypes. Male and female C57BL/6J mice underwent sham or repeated mild traumatic brain injury (rmTBI) and were tested for up to 9 weeks postinjury, where an anti-inflammatory/neuroprotective drug (minocycline) was introduced at 5 weeks postinjury in the drinking water. Repeated mild traumatic brain injury mice developed cold nociceptive hypersensitivity and negative affective states, as well as increased locomotor activity and risk-taking behavior. Minocycline reversed negative affect and pain hypersensitivities in male but not female mice. Repeated mild traumatic brain injury also produced an increase in microglial and brain-derived neurotropic factor mRNA transcripts in limbic structures known to be involved in nociception and affect, but many of these changes were sex dependent. Finally, we show that the antiepileptic drug, gabapentin, produced negative reinforcement in male rmTBI mice that was prevented by minocycline treatment, whereas rmTBI female mice showed a place aversion to gabapentin. Collectively, pain hypersensitivity, increased tonic-aversive pain components, and negative affective states were evident in both male and female rmTBI mice, but suppression of microglial reactivity was only sufficient to reverse behavioral changes in male mice. Neuroinflammation in limbic structures seems to be a contributing factor in behavioral changes resulting from rmTBI.

The aim of the present study was to examine the effects of attention–deficit/hyperactivity disorder (ADHD) –related psychostimulant use in the context of concussion risk and symptom recovery. Data were obtained from the National Collegiate Athletic Association Department of Defense Grand Alliance Concussion Assessment, Research, and Education (NCAA-DOD CARE) Consortium from 2014 to 2017. Relative to individuals without diagnosed ADHD (i.e., control), both ADHD diagnosis and the combination of ADHD diagnosis and psychostimulant use were associated with a greater risk of incurring a concussive injury. Following a concussive injury, ADHD diagnosis was associated with longer symptom recovery time relative to the control group. However, individuals with ADHD who use psychostimulants did not take longer to resolve symptoms than controls, suggesting that psychostimulants may have a positive influence on recovery. Regardless of time point, ADHD diagnosis was associated with an elevated number of concussion-related symptoms; however, this effect appears mitigated by having used ADHD-related psychostimulants. [ABSTRACT FROM AUTHOR]

Purpose: To describe nine youth soccer coaches' pedagogical responses to the implementation of the new guidelines on heading introduced by the United States Soccer Federation. The specific research questions we attempted to answer were: (a) What were the coaches' perspectives and practices regarding the coaching of heading? and (b) What factors shaped the coaches' perspectives and practices? Method: The theoretical framework employed was occupational socialization. Data were collected using four qualitative techniques and reduced to themes using analytic induction and constant comparison. Findings: Key findings were that the coaches fell into one of three groups: rejectors, acceptors, and skeptics. Differences in the coaches' acculturation, professional socialization, and organizational socialization were responsible for the coaches' differing responses to the new guidelines on heading. Conclusions: Should they transfer to other coaches, these findings should help coach educators to develop stronger programs. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the contribution of splenius capitis, sternocleidomastoid, and upper fibers of trapezius activation to the gains in rate of force development (RFD) of the head and neck during maximum voluntary ballistic contractions. Methods: RFD gain was facilitated by a single-session intervention for maximum voluntary ballistic contractions in the anterior direction, oriented at 45° to the midsagittal plane, which require active restraint of axial rotation. Muscle activation for the agonist (sternocleidomastoid) and 2 antagonists (splenius capitis and upper fibers of trapezius) was evaluated. The study sample included 12 physically active men (mean age, 22.6 y). RFD (N·m·s−1; 0–100 ms) and integrated muscle activity (50 ms before and 100 ms after force onset) were measured at 10 minutes, 20 minutes, and 2 days postintervention, relative to baseline. Muscle activation predictive of RFD gains was evaluated by linear regression analysis. RFD reproducibility was evaluated using the coefficient of variation of the typical error. Results: The intervention yielded a 1.95- to 2.39-fold RFD gain (P ≤.05), with greater RFD gain for participants with a lower peak moment of force (<10.9 N·m) than those with a higher peak moment (≥10.9 N·m) at baseline (P ≤.002). For the low group, 65% to 74% of the RFD gain was predicted by ipsilateral sternocleidomastoid activation, with ipsilateral splenius capitis activation predicting 77% to 92% of RFD gain for the high group. Absolute peak and impulse of static force were greater for the high than for the low group (P ≤.04). RFD reproducibility was high (coefficient of variation of the typical error ≤ 14.4%). Conclusions: The agonist- and antagonist-focused synergies might reflect different functional priorities, higher RFD gain compared with higher head–neck force. [ABSTRACT FROM AUTHOR]