Concussion Symptoms and Neurocognitive Performance of Children and Adolescents on Antidepressants

INTRODUCTION/PURPOSE

There is a well-established association between preexisting depression/anxiety and greater postconcussion symptom burden, but the potential impact of antidepressant medications has not been fully explored. The primary objective of this study was to compare preinjury/baseline and postinjury concussion symptom scores and neurocognitive performance of athletes on antidepressant medications, both with healthy controls and with those with depression/anxiety not on antidepressants.

METHODS

This is a cross-sectional study using data collected from 49,270 junior and high school athletes from computerized neurocognitive assessments (Immediate Post-Concussion Assessment and Cognitive Test [ImPACT]) administered between 2009 and 2018 held by the Massachusetts Concussion Management Coalition. The main outcome measures were symptom scores and neurocognitive performance measures, all of which were assessed both at baseline and postinjury. Statistical analysis included analysis of variance and Tukey pairwise comparisons for continuous variables and Fisher's exact test for categorical variables. Multivariate regression models were used to adjust for potential confounding variables.

RESULTS

Both at baseline and postinjury, athletes with depression/anxiety had mean total symptom scores that were more than double that of healthy controls regardless of antidepressant use. Although there were no significant differences in neurocognitive performance at baseline, depression/anxiety was associated with small but significant decreases in postinjury visual memory and visual motor scores.

CONCLUSIONS

Both at baseline and after sustaining a concussion, young athletes with depression/anxiety experience significantly greater symptom burden compared with healthy controls regardless of antidepressant use.

Time-Dependent Long-Term Effect of Memantine following Repetitive Mild Traumatic Brain Injury

Repetitive mild traumatic brain injury (rmTBI, e.g., sports concussions) may be associated with both acute and chronic symptoms and neurological changes. Despite the common occurrence of these injuries, therapeutic strategies are limited. One potentially promising approach is N-methyl-D-aspartate receptor (NMDAR) blockade to alleviate the effects of post-injury glutamatergic excitotoxicity. Initial pre-clinical work using the NMDAR antagonist, memantine, suggests that immediate treatment following rmTBI improves a variety of acute outcomes. It remains unclear (1) whether acute memantine treatment has long-term benefits and (2) whether delayed treatment following rmTBI is beneficial, which are both clinically relevant concerns. To test this, animals were subjected to rmTBI via a weight drop model with rotational acceleration (five hits in 5 days) and randomized to memantine treatment immediately, 3 months, or 6 months post-injury, with a treatment duration of one month. Behavioral outcomes were assessed at 1, 4, and 7 months post-injury. Neuropathological outcomes were characterized at 7 months post-injury. We observed chronic changes in behavior (anxiety-like behavior, motor coordination, spatial learning, and memory), as well as neuroinflammation (microglia, astrocytes) and tau phosphorylation (T231). Memantine treatment, either immediately or 6 months post-injury, appears to confer greater rescue of neuroinflammatory changes (microglia) than vehicle or treatment at the 3-month time point. Although memantine is already being prescribed chronically to address persistent symptoms associated with rmTBI, this study represents the first evidence of which we are aware to suggest a small but durable effect of memantine treatment in mild, concussive injuries. This effect suggests that memantine, although potentially beneficial, is insufficient to treat all aspects of rmTBI alone and should be combined with other therapeutic agents in a multi-therapy approach, with attention given to the timing of treatment.

Visual Impairment in Pre-Clinical Models of Mild Traumatic Brain Injury

Impairment in visual function is common after traumatic brain injury (TBI) in the clinical setting, a phenomenon that translates to pre-clinical animal models as well. In Morris et al. (2021), we reported histological changes following weight-drop-induced TBI in a rodent model including retinal ganglion cell (RGC) loss, decreased electroretinogram (ERG) evoked potential, optic nerve diameter reduction, induced inflammation and gliosis, and loss of myelin accompanied by markedly impaired visual acuity. In this review, we will describe several pre-clinical TBI models that result in injuries to the visual system, indicating that visual function may be impaired following brain injury induced by a number of different injury modalities. This underscores the importance of understanding the role of the visual system and the potential detrimental sequelae to this sensory modality post-TBI. Given that most commonly employed behavioral tests such as the Elevated Plus Maze and Morris Water Maze rely on an intact visual system, interpretation of functional deficits in diffuse models may be confounded by off- target effects on the visual system.

Factors Associated with Symptom Resolution after Aerobic Exercise Intervention in Adolescent and Young Adults with Concussion

BACKGROUND

Aerobic exercise facilitates postconcussion symptom resolution at the group level, but patient-level characteristics may affect the likelihood of treatment efficacy.

PURPOSE

This study aimed to investigate demographic and clinical characteristics, which differentiate postconcussion aerobic exercise treatment efficacy from nonefficacy in the intervention arm of a randomized clinical trial.

METHODS

Adolescent and young adult participants initiated a standardized aerobic exercise intervention within 14 d of concussion, consisting of self-selected exercise for 100 min·wk -1 at an individualized heart rate (80% of heart rate induced symptom exacerbation during graded exercise testing). Treatment efficacy was defined as symptom resolution within 28-d postconcussion. Treatment efficacy and nonefficacy groups were compared on demographics, clinical characteristics, intervention adherence, and persistent symptom risk using the Predicting Persistent Postconcussive Problems in Pediatrics (5P) clinical risk score.

RESULTS

A total of 27 participants (16.1 ± 2.3 yr old; range, 11-21 yr; 52% female) began the intervention, with a mean of 9.5 ± 3.7 d after concussion; half ( n = 13; 48%) demonstrated treatment efficacy (symptom resolution within 28 d postconcussion). Those whose symptoms resolved within 28 d had significantly lower preintervention postconcussion symptom inventory scores (21.2 ± 13.2 vs 41.4 ± 22.2; P < 0.01), greater adherence to the intervention (77% vs 36%; P = 0.05), and longer average exercise duration (median [interquartile range], 49.7 [36.8-68.6] vs 30.4 [20.7-34.7] min; P < 0.01) than those whose symptoms lasted more than 28 d. Groups were similar in age, sex, timing of intervention, and preintervention 5P risk score.

CONCLUSIONS

A standardized aerobic exercise intervention initiated within 14 d of concussion demonstrated efficacy for approximately half of participants, according to our definition of treatment efficacy. This multisite aerobic exercise intervention suggests that lower symptom severity, higher intervention adherence, and greater exercise duration are factors that increase the likelihood of symptoms resolving within 28 d of concussion.

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial Evaluating Transcranial Photobiomodulation as Treatment for Concussion

INTRODUCTION

Literature indicating that transcranial photobiomodulation (tPBM) may enable the brain to recover normal function after concussion, resulting in symptoms reduction, and improved cognitive function after concussion is limited by small sample sizes and lack of controls.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial examining the effect of 6 wk of tPBM in patients 11 yr or older who received care for persistent postconcussion symptoms between September 2012 and December 2015. Our primary outcome measure was the mean difference in Postconcussion Symptom Scale total score and the raw Immediate Postconcussion Assessment and Cognitive Testing composite scores between study entry and treatment completion. Participants received two, 10-min sessions either with tPBM units or via two placebo units, three times per week. We screened for potential confounding variables using univariable analyses. We entered covariables that differed between the two groups on univariable screening into a regression analysis. We considered adjusted odds ratio that did not cross one statistically significant.

RESULTS

Forty-eight participants completed the study. Most were female (63%), and a majority sustained their injury during sports or exercise (71%). Despite randomization, those that received tPBM therapy reported a greater number of previous concussions. After adjusting for the effect of previous concussions and multiple comparisons, there were no significant differences between tPBM and placebo groups at 3 or 6 wk of treatment.

CONCLUSIONS

Despite showing promise in previous investigations, our study did not show benefit to tPBM over placebo therapy in patients experiencing persistent postconcussion symptoms. Further investigation is needed to determine if varying the dose or timing alters the efficacy of tPBM after concussion.

Relationship Between Running Biomechanics and Core Temperature Across a Competitive Road Race

BACKGROUND

Outdoor races introduce environmental stressors to runners, and core temperature changes may influence runners' movement patterns. This study assessed changes and determined relationships between sensor-derived running biomechanics and core temperature among runners across an 11.27-km road race.

HYPOTHESIS

Core temperatures would increase significantly across the race, related to changes in spatiotemporal biomechanical measures.

STUDY DESIGN

Cross-sectional cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Twenty runners (9 female, 11 male; age, 48 ± 12 years; height, 169.7 ± 9.1 cm; mass, 71.3 ± 13.4 kg) enrolled in the 2022 Falmouth Road Race were recruited. Participants used lightweight technologies (ingestible thermistors and wearable sensors) to monitor core temperature and running biomechanics throughout the race. Timestamps were used to align sensor-derived measures for 7 race segments. Observations were labeled as core temperatures generally within normal limits (<38°C) or at elevated core temperatures (≥38°C). Multivariate repeated measures analyses of variance were used to assess changes in sensor-derived measures across the race, with Bonferroni post hoc comparisons for significant findings. Pearson's r correlations were used to assess the relationship between running biomechanics and core temperature measures.

RESULTS

Eighteen participants developed hyperthermic core temperatures (39.0°C ± 0.5°C); core temperatures increased significantly across the race (P < 0.01). Kinetic measures obtained from the accelerometers, including shock, impact, and braking g, all significantly increased across the race (P < 0.01); other sensor-derived biomechanical measures did not change significantly. Core temperatures were weakly associated with biomechanics (|r range|, 0.02-0.16).

CONCLUSION

Core temperatures and kinetics increased significantly across a race, yet these outcomes were not strongly correlated. The observed kinetic changes may have been attributed to fatigue-related influences over the race.

CLINICAL RELEVANCE

Clinicians may not expect changes in biomechanical movement patterns to signal thermal responses during outdoor running in a singular event.

Biomechanical changes identified during a marathon race among high-school aged runners

BACKGROUND

Despite the increasing popularity of endurance running competitions among adolescent runners, there is currently limited information regarding expected biomechanical changes across the duration of a long-distance running event, and the relationship between young runners' biomechanics and running performance. Wearable technology offers an ecological means to continuously assess runners' biomechanical data during outdoor running competitions.

RESEARCH QUESTION

Do adolescent athletes adopt changes in sensor-derived biomechanics throughout a marathon race, and are there relationships between race performance and biomechanical features among young marathoners?

METHODS

Fourteen high-school aged runners (9 M, 5 F; age: 16 ± 1 years, height: 170.8 ± 7.5 cm; mass: 63.6 ± 9.4 kg) wore lace-mounted sensors to record step-by-step biomechanics during a marathon race. Official race segment completion times were extracted across 5 race segments (5-K, 15-K, Half Marathon [21.1-K], 35-K, Marathon [42.2-K]). Within-participant repeated measures of covariance (pace) were conducted to assess changes in biomechanics across the race, with Bonferroni post-hoc comparisons. Pearson's r correlations were performed to assess the relationship between race finish times and biomechanics.

RESULTS

Pace was significantly slower (p-range: 0.002-0.005), contact times significantly longer, and stride lengths significantly shorter in the final segment compared to middle segments (p-range: 0.003-0.004). The rate of shock accumulation was significantly higher in the final race segment compared to the first three segments (p-range: 0.001-0.002). Moderate relationships existed between finish times and pace (r = -0.63), stride length (r = -0.62), and contact time (r = 0.51).

SIGNIFICANCE

Adolescent runners altered their gait patterns in the final marathon segment compared to earlier segments. Spatiotemporal measures were moderately correlated with race finish times, suggesting a link between faster run pace, increased stride lengths, and reduced contact time for improved running performance during an endurance race.

Pediatric Sport-Related Concussion: Recommendations From the Amsterdam Consensus Statement 2023

The 6th International Consensus Conference on Concussion in Sport, Amsterdam 2022, addressed sport-related concussion (SRC) in adults, adolescents, and children. We highlight the updated evidence-base and recommendations regarding SRC in children (5-12 years) and adolescents (13-18 years). Prevention strategies demonstrate lower SRC rates with mouthguard use, policy disallowing bodychecking in ice hockey, and neuromuscular training in adolescent rugby. The Sport Concussion Assessment Tools (SCAT) demonstrate robustness with the parent and child symptom scales, with the best diagnostic discrimination within the first 72 hours postinjury. Subacute evaluation (>72 hours) requires a multimodal tool incorporating symptom scales, balance measures, cognitive, oculomotor and vestibular, mental health, and sleep assessment, to which end the Sport Concussion Office Assessment Tools (SCOAT6 [13+] and Child SCOAT6 [8-12]) were developed. Rather than strict rest, early return to light physical activity and reduced screen time facilitate recovery. Cervicovestibular rehabilitation is recommended for adolescents with dizziness, neck pain, and/or headaches for greater than 10 days. Active rehabilitation and collaborative care for adolescents with persisting symptoms for more than 30 days may decrease symptoms. No tests and measures other than standardized and validated symptom rating scales are valid for diagnosing persisting symptoms after concussion. Fluid and imaging biomarkers currently have limited clinical utility in diagnosing or assessing recovery from SRC. Improved paradigms for return to school were developed. The variable nature of disability and differences in evaluating para athletes and those of diverse ethnicity, sex, and gender are discussed, as are ethical considerations and future directions in pediatric SRC research.

Lower Extremity Strength Relative to Body Mass in Pediatric Female Athletes: Implications for Anterior Cruciate Ligament Injury

This study compared lower extremity (LE) muscular strength by 3 groups of female athletes using chronological age and consideration of age of peak height velocity (PHV). Isometric quadriceps, hamstrings, and hip abductors strength were assessed from physically active, pediatric females. The body mass normalized isometric strength (N m/kg) was compared by the 3 age groups. There were 388 young female athletes (<10 years [14.2%], 11-14 years [48.7%], and 15-18 years [37.1%]). The body mass normalized LE strength was lower in 11-14 years compared with <10 years (quadriceps [P = .001], hamstrings [P = .001], and hip abductors [P = .037]) as well as in 15-18 years relative to <10 years in quadriceps (P = .001) and hamstrings (P = .001). The analysis results were consistent with both chronological age alone and incorporating effects of age of PHV. In short, body mass normalized LE strength (quadriceps, hamstrings, and hip abductors) of 11-14 years females was lower than <10 years females.

Subjective and Performance-Based Cognition and Their Associations with Head Injury History in Older Former National Football League Players

PURPOSE

Investigate the association between self-reported subjective and performance-based cognition among older (50-70 years) former professional American football players, as well as the relationship of cognitive measures with concussion history and years of football participation, as a proxy for repetitive head impact exposure.

METHODS

Among older former National Football League (NFL) players ( N = 172; mean age = 60.69 ± 5.64), associations of subjective (Patient Reported Outcome Measurement Information System Cognitive Function-Short Form) and performance-based cognitive measures (Brief Test of Adult Cognition by Telephone [BTACT] Executive Function and Episodic Memory indices) were assessed via univariable and multivariable regression models, with a priori covariates of depression and race. A similar univariate and multivariable regression approach assessed associations between concussion history and years of football participation with subjective and performance-based cognitive measures. In a sample subset ( n = 114), stability of subjective cognitive rating was assessed via partial correlation.

RESULTS

Subjective ratings of cognition were significantly associated with performance-based assessment, with moderate effect sizes (episodic memory ηp2 = 0.12; executive function ηp2 = 0.178). These associations were weakened, but remained significant ( P s < 0.05), with the inclusion of covariates. Greater concussion history was associated with lower subjective cognitive function ( ηp2 = 0.114, P < 0.001), but not performance-based cognition. The strength of association between concussion history and subjective cognition was substantially weakened with inclusion of covariates ( ηp2 = 0.057). Years of participation were not associated with measures of subjective or objective cognition ( P s > 0.05).

CONCLUSIONS

These findings reinforce the importance of comprehensive evaluation reflecting both subjective and objective measures of cognition, as well as the consideration of patient-specific factors, as part of a comprehensive neurobehavioral and health assessment of older former contact sport athletes.

Running gait adaptations among adolescent runners with soft tissue impairments following lateral ankle sprains

BACKGROUND

Lateral ankle sprains (LAS) frequently lead to residual soft tissue impairments, often attributed to biomechanical dysfunction during movement.

OBJECTIVE

To compare running biomechanics between adolescent runners with soft tissue pathologies following LAS (injured) and healthy runners (control) and between limbs.

DESIGN

Retrospective cohort study.

SETTING

Hospital-affiliated sports injury prevention center.

PARTICIPANTS

Twenty-five adolescent runners with a history of LAS and current ankle impingement or tendinopathy (23 female, 2 male; age: 15 ± 2 years; body mass index [BMI]: 19.5 ± 2.5 kg/m2 ; symptom duration: 1.1 ± 0.9 years), and 23 healthy controls without any LAS history (19 female, 4 male; age: 15 ± 1 years; BMI: 19.2 ± 2.7 kg/m2 ) were included in this study.

INTERVENTIONS

All participants completed a clinical gait assessment in which they ran at a self-selected speed on a force-plate instrumented treadmill, while two video cameras recorded two-dimensional sagittal and coronal views.

MAIN OUTCOME MEASURES

Foot rotation, step width, contact time, and cadence were compared between groups and limbs (involved, uninvolved [or "better" for bilateral cases]) using a multivariate analysis of variance (MANOVA). Rearfoot landing and foot strike type were compared between groups and limbs using a chi-square analysis.

RESULTS

The injured group had significantly increased step width (F = 4.71, p = .04; mean difference [MD] with SE: 1.5 [0.7] cm) compared to controls. The injured groups' involved limb had longer contact time (F = 4.62, p = .03; MDgroup : 12 [7] ms, MDlimb : 22 [11] ms) with more internal foot rotation (F = 14.60, p < .001; MDgroup : 2.2 [1.2] degrees, MDlimb : 4.2 [1.3] degrees) compared to controls and their contralateral limb. There were no significant differences for cadence (F = 2.43, p = .13; MD: 4 [3] steps/min), foot landing (X2  = 1.28, p = .53), or foot strike (X2  = 1.24, p = .54).

CONCLUSIONS

Spatiotemporal and kinematic running adaptations may predispose young runners with initial LAS to secondary soft tissue dysfunction due to loss of stability from ligamentous structures and an overreliance on myotendinous control. Clinicians may consider targeting these maladaptations during gait-training interventions.

Clinical assessment, treatment, and referral trends for adolescent runners seeking care at an injured runners' clinic

PURPOSE

Over a 10-year time frame, this study aimed to evaluate diagnosis, treatment, and referral trends for adolescent runners seeking care for running-related injuries (RRIs) at a clinic that specializes in running medicine.

METHODS

This study was a retrospective chart review of 392 adolescent runners (2,326 encounters) who sought care for RRIs between the years 2011 and 2021. Descriptive statistics were used to summarize clinical assessments, referrals, assistive devices, and medications prescribed or administered overall and by injury type. Chi-square analyses were used to compare proportions of services rendered across the 10-year time frame.

RESULTS

Patients most frequently received manual evaluations or special tests during clinic visits. Most visits resulted in at least one referral (91%), primarily for physical therapy or gait-training. Assistive devices and medications/supplements were offered at only 18% of patient visits. The majority of assessments (X2 = 69.7, p = 0.002), treatments (X2: 23.6-43.8, p: <  0.001-0.003), and referrals (X2 = 132, p <  0.001) were for shin injuries. Larger proportions of nutrition assessments (X2 = 40.7, p <  0.001), interventions (X2 = 26.8, p = 0.003), and referrals (X2 = 27.5, p = 0.002) were performed in or after the year 2015.

CONCLUSION

Clinic visits for shin injuries required the most clinical resources per episode of care. There were observed shifts in clinical assessment and treatment approaches to include more expanded nutritional and physiologic considerations.

Sport specialisation and performance-enhancing substance use by young athletes

Objectives

To investigate the association of reported legal performance enhancing substance (PES) use and consideration of banned PES use among sport-specialised and non-sport-specialised young athletes.

Methods and design

Cross-sectional study of 1049 young athletes enrolled in an injury prevention programme from 2013 to 2020. We used logistic regression modelling to determine the independent association between sports specialisation. We reported (1) legal PES use and (2) consideration of banned PES use after adjusting for the effects of gender, age, having a relative as a coach, unrestricted internet access, use of a weight training regimen, and weeknight hours of sleep.

Results

The final cohort consisted of 946 athletes with a mean age of 14. 56% were female, and 80% were sport-specialised athletes. 14% reported legal PES use, and 3% reported consideration of banned PES use. No difference was found between sport-specialised athletes who reported legal PES use (OR=1.4; 95% CI 0.81 to 2.43; p=0.23) or consideration of banned PES use (OR=3.2; 95% CI 0.78 to 14.92; p=0.1) compared with non-sport-specialised athletes. Reported legal PES use was more common among athletes who were male, older, used weight training, and slept less. Reported consideration of banned PES use was more common among male and older athletes.

Conclusions

PES use is not independently associated with sport specialisation in young athletes. Athlete sex, age, training, and sleep patterns are important factors for young athletes to consider in PES use.

Ankle Sprain History Does Not Significantly Alter Single- and Dual-Task Spatiotemporal Gait Mechanics

CONTEXT

Single- and dual-task walking gait assessments have been used to identify persistent movement and cognitive dysfunction among athletes with concussions. However, it is unclear whether previous ankle sprain injuries confound these outcomes during baseline testing. The purpose of this study was to determine the effects of (1) ankle sprain history and (2) time since prior ankle sprain injury on single- and dual-task spatiotemporal gait outcomes and cognitive measures.

DESIGN

Cross-sectional study.

METHODS

We assessed 60 college Division-I athletes (31 with ankle sprain history; 13 females and 18 males, 19.3 [0.8] y; 29 with no ankle sprain history, 14 females and 15 males, 19.7 [0.9] y) who completed injury history forms and underwent concussion baseline testing. Athletes completed single- and dual-task gait assessments by walking back and forth along an 8-m walkway for 40 seconds. Athletes wore a smartphone with an associated mobile application on their lumbar spine to record spatiotemporal gait parameters and dual-task cognitive performance. Separate multivariate analyses of variance were used to assess the effects of ankle sprain injury history on spatiotemporal measures, gait variability, and cognitive performance. We performed a multivariate regression subanalysis on athletes who reported time since injury (n = 23) to assess temporal effects on gait and cognitive performance.

RESULTS

Athletes with and without a history of ankle sprains had comparable spatiotemporal and gait variability outcomes during single- (P = .42; P = .13) and dual-task (P = .75; P = .55) conditions. Additionally, ankle sprain injury history did not significantly influence cognitive performance (P = .35). Finally, time since ankle sprain did not significantly affect single- (P = .75) and dual-task gait (P = .69), nor cognitive performance (P = .19).

CONCLUSIONS

Ankle sprain injury history did not significantly alter spatiotemporal gait outcomes nor cognitive performance during this common clinical assessment. Future studies may consider including athletes with ankle sprain injury history during concussion assessments.

Adolescent exercise-related lower leg pain musculotendinous characteristics

BACKGROUND

Exercise-related lower leg pain (ERLLP) is one of the most common injuries among adolescent runners; however, there is limited information available on lower extremity musculotendinous characteristics in relationship to injury. Ultrasound imaging has previously been used to evaluate musculotendinous structures among adults with chronic lower limb injuries. Similar measurement approaches may be adopted to assess young runners with ERLLP.

OBJECTIVE

To compare ultrasound-derived lower extremity musculotendinous thickness, echogenicity, and muscle fiber pennation angles between adolescent runners with and without ERLLP.

DESIGN

Cross-sectional design.

SETTING

Hospital-affiliated sports injury prevention center.

PARTICIPANTS

Twenty-eight adolescent runners with (N = 14) and without ERLLP (N = 14).

INTERVENTIONS

Runners' patellar and Achilles tendons, and tibialis anterior, medial gastrocnemius, abductor hallicus, and flexor digitorum brevis muscles were assessed with ultrasound imaging using standardized procedures.

MAIN OUTCOME MEASURES

Separate repeated measures multivariate analyses of covariance (covariate: gender) were used to compare groups and limbs for mass-normalized musculotendinous thickness, musculotendinous echogenicity, and extrinsic ankle muscle fiber pennation angles.

RESULTS

The adolescent ERLLP group had reduced average muscle size for all structures except the tibialis anterior compared to the uninjured group (mean difference [MD] range: -0.12-0.49 mm/kg; p range: .002-.05), and reduced average medial gastrocnemius pennation angles on their case limb compared to their contralateral limb and the uninjured group (MD range: -3.7-6.4°; p < .001). The ERLLP group additionally had reduced average patellar and Achilles tendon size (MD range: -0.14--0.15 mm/kg; p range: .02-.03), and lower Achilles tendon echogenicity compared to uninjured counterparts (MD: -18; p = .02).

CONCLUSIONS

Adolescent runners with ERLLP exhibited morphological musculotendinous changes that may occur either as a result of or as a contributing factor to pain and persistent dysfunction. The findings highlight key targets for rehabilitation for young, injured runners, particularly intrinsic foot muscle strengthening.

Outpatient Runners Clinic Visit Trends and Injury Characteristics Among 392 Child and Adolescent Patients: A 10-year Chart Review

OBJECTIVE

To evaluate clinic visits and running-related injury (RRI) characteristics among child and adolescent runners seeking care at an outpatient clinic over a 10-year time frame.

DESIGN

Retrospective chart review.

SETTING

Outpatient hospital-affiliated Injured Runners Clinic.

PATIENTS

Children and adolescent runners (6-17 years) with RRIs.

INDEPENDENT VARIABLES

We examined electronic medical records (EMRs) among child and adolescent patients in the hospital database from 2011 to 2021 to obtain RRI characteristics and key demographic factors.

MAIN OUTCOME MEASURES

We assessed volume and frequency of patient visits to the clinic by RRI characteristics. Chi square analyses were used to compare the proportion of clinic visits over time and injury trends by body region and diagnosis.

RESULTS

There were 392 patients (sex: 277 F; mean age: 16.1 ± 1.3 years) and an average of 5 clinic visits per diagnosis (5 ± 4 visits; min: 1 visit, max: 31 visits). Number of visits generally increased over time up to 2016 but declined most drastically during the years of the pandemic (2020-2021; χ 2 = 644, P < 0 .001). Of the 654 new injury diagnoses, 77.68% were attributed to repetitive stress. Bone stress injuries to the tibia were the most common RRI (χ 2 = 1940, P < 0 .001; N = 132; 20.2% of all injuries) and constituted most of the clinic visits (χ 2 = 9271, P < 0 .001; N = 591; 25.4% of all visits).

CONCLUSION

We identified that adolescents with overuse injuries, particularly bone stress injuries to the tibia, constituted most of the visits to the outpatient healthcare setting. Clinicians should emphasize injury prevention efforts in clinical practice to reduce RRI burden.

Contact or Collision Sport History, Repetitive Neurotrauma, and Patient-Reported Outcomes in Early to Midadulthood

CONTEXT

Data on the early to midlife effects of repetitive neurotrauma on patient-reported outcomes have been delimited to homogeneous samples of male athletes without comparison groups or accounting for modifying factors such as physical activity.

OBJECTIVE

To determine the effect of contact or collision sport participation and repetitive neurotrauma on patient-reported outcomes among early to middle-aged adults.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 113 adults (53 [46.9%] men, 60 [53.1%] women; age = 34.88 ± 11.80 years) in 4 groups: (1) physically inactive individuals with no repetitive head impact (RHI) exposure (NON); (2) noncontact sport athletes and nonathletes with no RHI exposure who were currently physically active (NCA); (3) former high-risk sport athletes with an RHI history who were physically active (HRS); and (4) former rugby players with prolonged RHI exposure who remained physically active.

MAIN OUTCOME MEASURE(S)

The 12-Item Short-Form Health Survey (SF-12), Apathy Evaluation Scale-self-rated version (AES-S), Satisfaction With Life Scale (SWLS), and Sport Concussion Assessment Tool-5th Edition (SCAT5) Symptom and Symptom Severity Checklist.

RESULTS

The NON group had worse self-rated physical function than the NCA group as assessed by the SF-12 physical component summary (P = .03) and worse self-rated apathy (AES-S) and satisfaction with life (SWLS) than the NCA (P = .03 for both) and HRS groups (P = .03 and P = .040, respectively). We observed no group differences for self-rated mental health (SF-12 mental component summary; P = .26) or symptoms (SCAT5; P = .42). Career duration was not associated with any patient-reported outcomes.

CONCLUSIONS

A history of contact or collision sport participation and career duration did not negatively affect patient-reported outcomes in physically active, early to middle-aged adults. However, physical inactivity status was negatively associated with patient-reported outcomes in these individuals in the absence of an RHI history.

Adolescents With More Oculomotor and Vestibular Signs of Sport-Related Concussion Benefit from Aerobic Exercise: An Exploratory Analysis

Abstract Early targeted heart rate (HR) aerobic exercise has been shown to reduce the duration of recovery from sport-related concussion (SRC) as well as the incidence of persistent post-concussive symptoms (PPCS). It is not known, however, if more severe oculomotor and vestibular presentations of SRC benefit from a prescription of aerobic exercise. The current study is an exploratory analysis of two published randomized controlled trials that compared aerobic exercise within 10 days of injury with a placebo-like stretching intervention. Combining the two studies yielded a larger sample size to stratify severity of concussion based on the number of abnormal physical examination signs present at the initial office evaluation, which were confirmed with self-reported symptoms and recovery outcomes. The most discriminant cut-off was between those who had ≤3 oculomotor and vestibular signs and those who had >3 signs. Aerobic exercise (hazard ratio = 0.621 [0.412, 0.936], p = 0.023) reduced recovery times even when controlling for site (hazard ratio = 0.461 [0.303, 0.701], p < 0.001), severity (hazard ratio = 0.528 [0.325, 0.858], p = 0.010) and the interaction term of intervention and severity (hazard ratio = 0.972 [0.495, 1.909], p = 0.935). Adolescents who presented with >3 signs and were assigned to the placebo-like stretching group had a PPCS incidence of 38%, which was the highest of all subgroups (aerobic exercise and ≤3 findings: 8%; stretching and ≤3 findings: 11%; aerobic exercise and >3 findings: 21%). This exploratory study provides pilot evidence that prescribed sub-symptom threshold aerobic exercise treatment early after SRC may be effective for adolescents with more oculomotor and vestibular physical examination signs and should be validated in future adequately powered trials.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

OBJECTIVES

To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6).

DATA SOURCES

Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation.

ELIGIBILITY CRITERIA

(1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC.

DATA EXTRACTION

Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool.

RESULTS

Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children.

CONCLUSION

Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

Joint Injury, Osteoarthritis, and Cardiovascular Disease Risk Factors in Former National Football League Athletes: An NFL-LONG Study

CONTEXT

Individuals with lower extremity osteoarthritis (OA) have a 25% greater risk of cardiovascular disease (CVD) than those without OA. The prevalence of traumatic joint injuries among National Football League (NFL) players exposes these athletes to an elevated risk for OA and potentially a greater risk of cardiovascular risk factors (CRFs) and CVD.

OBJECTIVES

To examine the associations between a history of lower extremity joint injury, lower extremity OA, and the prevalence of CRFs and CVD among former NFL athletes.

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

Former NFL players completed a comprehensive health questionnaire that was used in an ongoing study, the Neurologic Function Across the Lifespan: A Prospective, Longitudinal, and Translational Study for Former NFL Players (NFL-LONG). A subsample of 1738 former players reported lifetime medical diagnoses including CVD or CRFs.

MAIN OUTCOME MEASURE(S)

Crude and adjusted prevalence ratios (PRsadj) characterized the associations between CVD or CRFs and injury, OA diagnosis, or both among athletes who reported (1) no history of lower extremity joint injury or surgery and no diagnosed OA, (2) a history of lower extremity joint injury or surgery and no diagnosed OA, and (3) a history of lower extremity joint injury or surgery and diagnosed OA.

RESULTS

Neither a history of lower extremity joint injury (PRadj = 1.34; 95% CI = 0.86, 2.07) nor a history of lower extremity joint injury and diagnosed OA (PRadj = 1.41; 95% CI = 0.89, 2.25) was significantly associated with CVD. However, CRFs were 30% and 53% more prevalent in former players with lower extremity joint injury and no diagnosed OA (PRadj = 1.30; 95% CI = 1.12, 1.50) and those with lower extremity joint injury and diagnosed OA (PRadj = 1.53; 95% CI = 1.31, 1.78), respectively, versus athletes with no history of either condition.

CONCLUSIONS

The prevalence of CRFs was highest among former NFL athletes with a history of lower extremity joint injury and diagnosed OA. These findings provide insight regarding the potential pathways to chronic diseases that may be initiated by joint injury early in life.

Role of biomarkers and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion: a systematic review

OBJECTIVE

Determine the role of fluid-based biomarkers, advanced neuroimaging, genetic testing and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion (SRC).

DESIGN

Systematic review.

DATA SOURCES

Searches of seven databases from 1 January 2001 through 24 March 2022 using keywords and index terms relevant to concussion, sports and neurobiological recovery. Separate reviews were conducted for studies involving neuroimaging, fluid biomarkers, genetic testing and emerging technologies. A standardised method and data extraction tool was used to document the study design, population, methodology and results. Reviewers also rated the risk of bias and quality of each study.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they: (1) were published in English; (2) represented original research; (3) involved human research; (4) pertained only to SRC; (5) included data involving neuroimaging (including electrophysiological testing), fluid biomarkers or genetic testing or other advanced technologies used to assess neurobiological recovery after SRC; (6) had a minimum of one data collection point within 6 months post-SRC; and (7) contained a minimum sample size of 10 participants.

RESULTS

A total of 205 studies met inclusion criteria, including 81 neuroimaging, 50 fluid biomarkers, 5 genetic testing, 73 advanced technologies studies (4 studies overlapped two separate domains). Numerous studies have demonstrated the ability of neuroimaging and fluid-based biomarkers to detect the acute effects of concussion and to track neurobiological recovery after injury. Recent studies have also reported on the diagnostic and prognostic performance of emerging technologies in the assessment of SRC. In sum, the available evidence reinforces the theory that physiological recovery may persist beyond clinical recovery after SRC. The potential role of genetic testing remains unclear based on limited research.

CONCLUSIONS

Advanced neuroimaging, fluid-based biomarkers, genetic testing and emerging technologies are valuable research tools for the study of SRC, but there is not sufficient evidence to recommend their use in clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42020164558.

Beyond acute concussion assessment to office management: a systematic review informing the development of a Sport Concussion Office Assessment Tool (SCOAT6) for adults and children

OBJECTIVES

To systematically review the scientific literature regarding the assessment of sport-related concussion (SRC) in the subacute phase (3-30 days) and provide recommendations for developing a Sport Concussion Office Assessment Tool (SCOAT6).

DATA SOURCES

MEDLINE, Embase, PsycINFO, Cochrane CENTRAL, CINAHL, SPORTDiscus and Web of Science searched from 2001 to 2022. Data extracted included study design, population, definition of SRC diagnosis, outcome measure(s) and results.

ELIGIBILITY CRITERIA

(1) Original research, cohort studies, case-control studies, diagnostic accuracy and case series with samples >10; (2) SRC; (3) screening/technology that assessed SRC in the subacute period and (4) low risk of bias (ROB). ROB was performed using adapted Scottish Intercollegiate Guidelines Network criteria. Quality of evidence was evaluated using the Strength of Recommendation Taxonomy classification.

RESULTS

Of 9913 studies screened, 127 met inclusion, assessing 12 overlapping domains. Results were summarised narratively. Studies of acceptable (81) or high (2) quality were used to inform the SCOAT6, finding sufficient evidence for including the assessment of autonomic function, dual gait, vestibular ocular motor screening (VOMS) and mental health screening.

CONCLUSION

Current SRC tools have limited utility beyond 72 hours. Incorporation of a multimodal clinical assessment in the subacute phase of SRC may include symptom evaluation, orthostatic hypotension screen, verbal neurocognitive tests, cervical spine evaluation, neurological screen, Modified Balance Error Scoring System, single/dual task tandem gait, modified VOMS and provocative exercise tests. Screens for sleep disturbance, anxiety and depression are recommended. Studies to evaluate the psychometric properties, clinical feasibility in different environments and time frames are needed.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

Gymnastics and concussions: A retrospective chart review

OBJECTIVE

The purpose of this study was to investigate the clinical presentation (using PCSS), mechanism of injury, and recovery time of concussions sustained by gymnasts.

METHODS

A retrospective chart review was performed at Boston Children's Hospital: Sports Medicine Clinic. Patients were identified with the words 'gymnastics' and 'concussion.' Male and female gymnasts were included if they sustained a concussion during gymnastics training or competition and were between the ages of 6-22 years old. Sex, age, injury site, diagnosis, mechanism of injury, and time to presentation are described. Patients were compared during different types of gymnastics events for overall symptom burden, and individual symptom severities.

RESULTS

A total of 201 charts were assessed over a 6-year period and 62 patients met inclusion criteria. Floor exercise was the most common event at the time of injury. Loss of consciousness occurred in 20% of injuries. There was no significant association between the type of event and PCSS upon initial clinical visit (p = 0.82). A total of 13 gymnasts returned to the clinic for a subsequent injury after their concussion (Table 3).

CONCLUSIONS

Gymnasts are at risk for sport-related concussions. Most gymnasts reporting to a tertiary care center with the diagnosis of concussion sustain their injuries during floor exercise.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Adolescent Marathon Training: Prospective Evaluation of Musculotendinous Changes During a 6-Month Endurance Running Program

OBJECTIVES

Assess changes in lower extremity musculotendinous thickness, tissue echogenicity, and muscle pennation angles among adolescent runners enrolled in a 6-month distance running program.

METHODS

We conducted prospective evaluations of adolescent runners' lower extremity musculotendinous changes at three timepoints (baseline, 3 months, and 6 months) throughout a progressive marathon training program. Two experienced researchers used an established protocol to obtain short- and long-axis ultrasound images of the medial gastrocnemius, tibialis anterior, flexor digitorum brevis, abductor hallicus, and Achilles and patellar tendons. ImageJ software was used to calculate musculotendinous thickness and echogenicity for all structures, and fiber pennation angles for the ankle extrinsic muscles. Repeated measures within-subject analyses of variance were conducted to assess the effect of endurance training on ultrasound-derived measures.

RESULTS

We assessed 11 runners (40.7% of eligible runners; 6F, 5M; age: 16 ± 1 years; running experience: 3 ± 2 years) who remained injury-free and completed all ultrasound evaluation timepoints. Medial gastrocnemius muscle (F_2,20  = 3.48, P = .05), tibialis anterior muscle (F_2,20  = 7.36, P = .004), and Achilles tendon (F_2,20  = 3.58, P = .05) thickness significantly increased over time. Echogenicity measures significantly decreased in all muscles (P-range: <.001-.004), and increased for the patellar tendon (P < .001) during training. Muscle fiber pennation angles significantly increased for ankle extrinsic muscles (P < .001).

CONCLUSIONS

Adolescent runners' extrinsic foot and ankle muscles increased in volume and decreased in echogenicity, attributed to favorable distance training adaptations across the 6-month timeframe. We noted tendon thickening without concomitantly increased echogenicity, signaling intrasubstance tendon remodeling in response to escalating distance.

Influential Factors and Preliminary Reference Data for a Clinically Feasible, Functional Reaction Time Assessment: The Standardized Assessment of Reaction Time

CONTEXT

Clinical reaction-time (RT) measures are frequently used when examining patients with concussion but do not correlate with functional movement RT. We developed the Standardized Assessment of RT (StART) to emulate the rapid cognitive demands and whole-body movement needed in sport.

OBJECTIVE

To assess StART differences across 6 cognitive-motor combinations, examine potential demographic and health history confounders, and provide preliminary reference data for healthy collegiate student-athletes.

DESIGN

Prospective, cross-sectional study.

SETTING

Clinical medicine facilities.

PATIENTS OR OTHER PARTICIPANTS

A total of 89 student-athletes (56 [62.9%] men, 33 [37.1%] women; age = 19.5 ± 0.9 years, height = 178.2 ± 21.7 cm, mass = 80.4 ± 24 kg; no concussion history = 64 [71.9%]).

MAIN OUTCOME MEASURE(S)

Student-athletes completed health history questionnaires and StART during preseason testing. The StART consisted of 3 movements (standing, single-legged balance, and cutting) under 2 cognitive states (single task and dual task [subtracting by 6's or 7's]) for 3 trials under each condition. The StART trials were calculated as milliseconds between penlight illumination and initial movement. We used a 3 × 2 repeated-measures analysis of variance with post hoc t tests and 95% CIs to assess StART cognitive and movement differences, conducted univariable linear regressions to examine StART performance associations, and reported StART performance as percentiles.

RESULTS

All StART conditions differed (P ≤ .03), except single-task standing versus single-task single-legged balance (P = .36). Every 1-year age increase was associated with an 18-millisecond (95% CI = 8, 27 milliseconds) slower single-task cutting RT (P < .001). Female athletes had slower single-task (15 milliseconds; 95% CI = 2, 28 milliseconds; P = .02) and dual-task (28 milliseconds; 95% CI = 2, 55 milliseconds; P = .03) standing RT than male athletes. No other demographic or health history factors were associated with any StART condition (P ≥ .056).

CONCLUSIONS

The StART outcomes were unique across each cognitive-motor combination, suggesting minimal subtest redundancy. Only age and sex were associated with select outcomes. The StART composite scores may minimize confounding factors, but future researchers should consider age and sex when providing normative data.

Incorporation of concussion history as part of the LIfestyle for BRAin Health (LIBRA) modifiable factors risk score and associations with cognition in older former National Football League players

OBJECTIVE

Investigate associations between the LIfestyle for BRAin Health (LIBRA) risk score with odds of mild cognitive impairment (MCI) diagnosis and cognitive function, incorporating concussion history.

METHODS

Former National Football League (NFL) players (N = 1050; mean age = 64.8 ± 9.0-years) completed initial testing for integration of concussion history into LIBRA scores (i.e., modified-LIBRA) and completed the Brief Test of Adult Cognition by Telephone (BTACT). Modified-LIBRA score (including concussion history) associations with odds of MCI and cognitive dysfunction were assessed via logistic and linear regression.

RESULTS

The highest quartile LIBRA scores were six times more likely to have a diagnosis of MCI compared to the lowest quartile (OR = 6.27[3.61, 10.91], p < 0.001). Modified-LIBRA scores significantly improved model fit for odds of MCI above original LIBRA scores (χ² (1) = 7.76, p = 0.005) and accounted for a greater fraction of variance in executive function (ΔR²  = 0.02, p = 0.003) and episodic memory (ΔR²  = 0.02, p = 0.002).

CONCLUSIONS

Modified-LIBRA score, incorporating concussion history, may help monitoring risk status in former contact sport athletes, by targeting modifiable, lifestyle-related risk factors.

Intrinsic and extrinsic factors contributing to running-related lower limb injuries among adolescent runners

The purpose of this study was to assess which combination of intrinsic and extrinsic factors contribute to running-related injury (RRI)among adolescent cross-country, track, and long-distance runners. We conducted a retrospective study at a hospital-affiliated sports injury prevention centre of 130 adolescent runners (F: 62.1%, M: 37.9%; cross-country: 34.1%, track: 56.1%, long-distance running: 9.8%) who underwent an Injury Prevention Evaluation between 2013 and 2021. The evaluation included a questionnaire on personal and training factors, and standardised physical assessments. We used a binomial logistic regression to assess the influence of demographics, lower extremity strength and alignment, training (running volume and intensity, weight training), and dietary factors on RRIs. There were 38 adolescent runners who reported RRIs (ankle sprains: N = 16, shin splints: N = 9, stress fractures: N = 13). Female sex (odds ratio [OR]: 4.58 [1.37, 15.37]; p = 0.01), reduced weekday hours of sleep (OR: 1.75 [1.04, 2.95]; p = 0.04), reduced hip abduction strength (OR: 1.02 [1.00, 1.04]; p = 0.05), and intention to lose weight to improve athletic performance (OR: 4.58 [1.00, 21.28]; p = 0.05) were associated with RRIs. These intrinsic and extrinsic risk factors may represent targets for injury prevention for adolescent runners.

Relationship and Latent Factors Between Clinical Concussion Assessments and the Functional Standardized Assessment of Reaction Time (StART)

OBJECTIVE

To examine the relationships and latent factors within the Standardized Assessment of Reaction Time (StART), and between StART and current clinical assessments.

DESIGN

Cross-sectional study.

SETTING

Clinical medicine facility.

PARTICIPANTS

Eighty-nine healthy collegiate student-athletes (63% male, age: 19.5 ± 0.9 years, 28% ≥1 concussion history).

ASSESSMENT OF RISK FACTORS

Student-athletes completed StART and clinical assessments during preinjury testing.

MAIN OUTCOME MEASURES

Standardized Assessment of Reaction Time consisted of 3 conditions (standing, single-leg balance, cutting) under 2 cognitive states (single task and dual task) for 3 trials each condition. Clinical assessments were the Sport Concussion Assessment Tool (SCAT) symptom checklist, Standardized Assessment of Concussion (SAC), tandem gait (single task and dual task), and Immediate PostConcussion Assessment and Cognitive Testing (ImPACT). We used Pearson- r correlation coefficients and exploratory factor analysis (EFA) to examine relationships and latent factors between StART and clinical assessments.

RESULTS

Null to moderate correlations presented among the StART outcomes (r range: 0.06-0.70), and null to small correlations between StART and clinical assessments (r range: -0.16 to 0.34). The three-factor EFA for solely StART explained 70.6% total variance: functional movement (cutting), static dual-task (standing and single-leg balance), and static single task (standing and single-leg balance). The five-factor EFA for StART and clinical assessments explained 65.8% total variance: gait (single-task and dual-task tandem gait), functional movement (StART single-task and dual-task cutting), static dual-task (StART standing, single-leg balance), neurocognitive (ImPACT verbal memory, visual memory, visual-motor speed), and static single task (StART standing, single-leg balance). No other outcomes met the factor loading threshold.

CONCLUSIONS

StART displayed 3 distinct categories and had minimal redundancy within its subtests. StART did not meaningfully correlate with clinical assessments, suggesting that StART provides unique information by examining more functional, reactive movement.

A Comparison of Factors Associated with Running-Related Injuries between Adult and Adolescent Runners

Background

There are multiple personal and environmental factors that influence the risk of developing running-related injuries (RRIs). However, it is unclear how these key clinical factors differ between adult and adolescent runners.

Purpose

The purpose of this study was to compare anthropometric, training, and self-reported outcomes among adult and adolescent runners with and without lower extremity musculoskeletal RRIs.

Study Design

Cross-sectional study.

Methods

Questionnaire responses and clinical assessment data were extracted from 38 adult runners (F: 25, M: 13; median age: 23 [range 18-36]) and 91 adolescent runners (F: 56, M: 35; median age: 15 [range 14-16]) who underwent a physical injury prevention evaluation at a hospital-affiliated sports injury prevention center between 2013 and 2021. Participants were sub-grouped into those with (adults: 25; adolescents: 38) and those without (adults: 13; adolescents: 53) a history of self-reported RRIs based on questionnaire responses. Multivariate analyses of covariance (MANCOVA) covarying for gender were conducted to compare outcomes across groups.

Results

Adult runners had lower Functional Movement Screen™ (FMS™) scores (mean differences [MD]: -1.4, p=0.01), were more likely to report intentional weight-loss to improve athletic performance (% difference: 33.0%; p:<.001), and more frequently included resistance training into their training routines (% difference: 21.0%, p=0.01) compared to adolescents. Those with a history of RRIs were more likely to report intentional weight-loss compared to uninjured runners (% difference: 21.3; p=0.02) and had shorter single leg bridge durations than those without RRIs (RRI: 57.9±30, uninjured: 72.0±44, p=0.01).

Conclusion

The findings indicate that addressing aspects of biomechanics identified by the FMS™ and behaviors of weight loss as an effort to improve performance may represent targets for the prevention of RRIs for adult and adolescent runners, given the association with history of RRIs.

Level of Evidence

3.

Incidence, prevalence and risk factors for low back pain in adolescent athletes: a systematic review and meta-analysis

OBJECTIVE

To investigate the incidence, prevalence, risk factors and morphological presentations of low back pain (LBP) in adolescent athletes.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Medline, Embase, CINAHL via EBSCO, Web of Science, Scopus.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies evaluating the incidence and/or prevalence of LBP in adolescent athletes across all sports.

RESULTS

There were 80 studies included. The pooled incidence estimate of LBP in adolescent athletes was 11% (95% CI 8% to 13%, I²=0%) for 2 years, 36.0% (95% CI 4% to 68%, I²=99.3%) for 12 months and 14% (95% CI 7% to 22%, I²=76%) for 6 months incidence estimates. The pooled prevalence estimate of LBP in adolescent athletes was 42% (95% CI 29% to 55%, I²=96.6%) for last 12 months, 46% (95% CI 41.0% to 52%, I²=56%) for last 3 months and 16% (95% CI 9% to 23%, I²=98.3%) for point prevalence. Potential risk factors were sport participation, sport volume/intensity, concurrent lower extremity pain, overweight/high body mass index, older adolescent age, female sex and family history of LBP. The most common morphology reported was spondylolysis. Methodological quality was deemed high in 73% of cross-sectional studies and in 30% of cohort studies. Common reasons for downgrading at quality assessment were use of non-validated survey instruments and imprecision or absence of LBP definition.

SUMMARY/CONCLUSION

LBP is common among adolescent athletes, although incidence and prevalence vary considerably due to differences in study methodology, definitions of LBP and data collection.

PROSPERO REGISTRATION NUMBER

CRD42020157206.

Adolescents with Sport-Related Concussion Who Adhere to Aerobic Exercise Prescriptions Recover Faster

PURPOSE

There is growing evidence that subsymptom threshold aerobic exercise speeds recovery from sport-related concussion (SRC). It is not known whether there is a direct relationship between adherence to a personalized exercise prescription and recovery or if initial symptom burden affects adherence to the prescription.

METHODS

This study was a planned secondary analysis of one arm of a randomized controlled trial. Male and female adolescent athletes (age 13-18 yr) presenting within 10 d of SRC were given aerobic exercise prescriptions based on their heart rate threshold at the point of exercise intolerance on a graded treadmill test. Adherence was determined objectively with HR monitors and compared against time to recovery. Participants who completed at least two-thirds of their aerobic exercise prescription were considered to be adherent.

RESULTS

Sixty-one percent of adolescents met the adherence criterion. Those who were adherent were more symptomatic and were more exercise intolerant at their initial visit, yet they recovered faster than those who were not adherent (median recovery time, 12 (interquartile range, 9-22) d vs 21.5 (interquartile range, 13-29.8) d; P = 0.016). On linear regression, adherence during week 1 was inversely related to recovery time ( β = -0.002 (-0.003, 0.0), P = 0.046) and to initial exercise tolerance ( β = -0.886 (-1.385, -0.387), P < 0.001), but not to initial symptom severity ( β = 0.545 (-0.232, 1.323), P = 0.146). No adverse events or near misses were reported.

CONCLUSIONS

Adherence to individualized subsymptom threshold aerobic exercise within the first week of evaluation is associated with faster recovery from SRC. The data suggest that initial degree of exercise intolerance, but not initial symptom severity, affects adherence to aerobic exercise prescribed to adolescents within 10 d of SRC.

The stability of self-reported professional football concussion history among former players: A longitudinal NFL-LONG study

OBJECTIVES

To examine the stability of former National Football League (NFL) players' recall of professional football concussion.

METHODS

Two-hundred-and-nine former NFL players (ceasing football participation before/in 2001) completed surveys in 2001, 2010, and 2019 and reported the number of concussions sustained during their professional careers (0, 1 … 10, >10). Participants were categorized into four 'recall stability' groups, based upon concussion recall [e.g., 'Same' (same number recalled), 'Increased' (more recalled than in prior time point)]. In 2019, participants completed measures of functioning (e.g., PROMIS Cognitive Function, Anxiety, Depression). Fleiss Kappa and generalized linear mixed models (GLMM)-based ordinal measures Kappa assessed stability across time points. 'Recall stability group' functioning scores were compared.

RESULTS

Overall, 45.9% recalled more concussions over time; 14.8% reported the same number. Fleiss Kappa and GLMM-based ordinal measures Kappa suggested fair (0.22, 95% CI: 0.26, 0.38) and moderate stability (0.41, 95% CI: 0.35, 0.46), respectively. Higher cognitive functioning (P = 0.002), lower anxiety (P = 0.003), and lower depression (P = 0.007) were observed in the 'Same' vs 'Increased' groups.

CONCLUSIONS

Despite subtle time-based variations in reporting, professional football concussion history recall was relatively stable. Better cognitive and psychological functioning was associated with greater stability in concussion recall.

Measurement implications on the association between self-reported concussion history and depression: An NFL-LONG study

ObjectiveThis study examined how associations of self-reported concussion history and depression vary based on different variable characterizations. Methods Former NFL players (n = 1,697) completed a General Health Survey, indicating the number of concussions they sustained during their football career and whether a physician had diagnosed them with depression, and the PROMIS 4-item Depression scale. Self-reported concussion history was characterized as: a 3-category variable (0, 1-2, 3+) with (1) indicator variables and (2) as an ordinal variable; a 5-category variable (0, 1-2, 3-5, 6-9, 10+) with (3) indicator variables and (4) as an ordinal variable; and (5) the original interval scale (0, 1, 2,…, 10, 10+). Depression was characterized as: (1) physician diagnosis (yes/no); and the PROMIS 4-item Depression scale treated as: (2) the original T-score variable and (3) using a cut-off of a T-score >60 versus ≤60. Regression models with various combinations of the characterizations, while adjusting for age, race/ethnicity, education, pain interference, and stress level, estimated prevalence ratios and mean differences for binary and continuous outcomes, respectively. Concussion history-related effect estimates were compared across all models. Results Self-reported concussion history emerged as a significant predictor of each depression measure. With a higher number of concussions reported, be it via the categories or the interval scale, stronger associations between self-reported concussion history and depression were observed. Conclusions The various approaches to characterize self-reported concussion history and depression provided evidence of significant associations between the two variables, with the degree of association varying based on characterization of each construct.

Postconcussion Exercise Volume Associations With Depression, Anxiety, and Dizziness Symptoms, and Postural Stability: Preliminary Findings

OBJECTIVE

To examine the association between postconcussion exercise volume and changes in depression, anxiety, dizziness, and postural stability.

DESIGN

Secondary analysis of a single-site prospective clinical trial.

SETTING

Cerebrovascular research laboratory.

PARTICIPANTS

Participants completed questionnaires and underwent tests of gait and balance within 2 weeks of a concussion (mean = 11 ± 3 days postconcussion) and approximately 1 month later (mean = 41 ± 7 days postconcussion). Exercise volume was tracked by weekly exercise logs.

INTERVENTIONS

On the basis of a previous work classifying exercise volume following concussion, we grouped participants according to self-reported exercise volume between visits as high exercise volume (≥150 min/wk) or low exercise volume (<150 min/wk).

MAIN OUTCOME MEASURES

Participants completed assessments evaluating anxiety and depression (Hospital Anxiety and Depression Scale), dizziness (Dizziness Handicap Inventory), and postural stability (tandem gait and modified Balance Error Scoring System).

RESULTS

Thirty-eight participants completed the study, of which 22 were in the high exercise volume group (mean = 71 ± 40 min/wk; 16.8 ± 2.1 years; 59% female) and 16 were in the low exercise volume group (mean = 379 ± 187 min/wk; 17.5 ± 2.1 years; 31% female). Although depression symptoms were not significantly different initially (mean difference = 1.5; 95% CI, -0.68 to 3.68; P = .24), the high exercise volume group had significantly lower depression symptom scores at follow-up (mean difference = 3.0; 95% CI, 1.40 to 4.47; P < .001). Anxiety symptoms (mean difference = 2.8; 95% CI, 0.3 to 5.4; P = 0.03), dizziness symptoms (mean difference = 10.9; 95% CI, 0.2 to 21.5; P = .047), single-task tandem gait (mean difference = 3.1 seconds; 95% CI, 0.2 to 6.0; P = .04), and dual-task tandem gait (mean difference = 4.2 seconds; 95% CI, 0.2 to 8.2; P = .04) were significantly better among the high exercise volume group.

CONCLUSION

Greater exercise volumes were associated with lower depression, anxiety, and dizziness symptoms, and faster tandem gait performance. These preliminary findings suggest a potentially beneficial role for exercise within several different domains commonly affected by concussion.

Dizziness, Psychosocial Function, and Postural Stability Following Sport-Related Concussion

OBJECTIVE

To examine if self-reported dizziness is associated with concussion symptoms, depression and/or anxiety symptoms, or gait performance within 2 weeks of postconcussion.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PARTICIPANTS

Participants were diagnosed with a concussion within 14 days of initial testing (N = 40). Participants were divided into 2 groups based on their Dizziness Handicap Inventory (DHI) score: 36 to 100 = moderate/severe dizziness and 0 to 35 = mild/no dizziness.

INTERVENTIONS

Participants were tested on a single occasion and completed the DHI, hospital anxiety and depression scale (HADS), Patient Health Questionnaire-9 (PHQ-9), and Post-Concussion Symptom Inventory (PCSI). Three different postural control tests were use: modified Balance Error Scoring System, single-/dual-task tandem gait, and a single-/dual-task instrumented steady-state gait analysis.

MAIN OUTCOME MEASURES

Comparison of patient-reported outcomes and postural control outcomes between moderate/severe (DHI ≥ 36) and mild/no (DHI < 36) dizziness groups.

RESULTS

Participants with moderate/severe dizziness (n = 19; age = 17.1 ± 2.4 years; 63% female) reported significantly higher symptom burden (PSCI: 43.0 ± 20.6 vs 22.8 ± 15.7; P = 0.001) and had higher median HADS anxiety (6 vs 2; P < 0.001) and depression (6 vs 1; P = 0.001) symptom severity than those with no/minimal dizziness (n = 21; age = 16.5 ± 1.9; 38% female). During steady-state gait, moderate/severe dizziness group walked with significantly slower single-task cadence (mean difference = 4.8 steps/minute; 95% confidence interval = 0.8, 8.8; P = 0.02) and dual-task cadence (mean difference = 7.4 steps/minute; 95% confidence interval = 0.7, 14.0; P = 0.04) than no/mild dizziness group.

CONCLUSION

Participants who reported moderate/severe dizziness reported higher concussion symptom burden, higher anxiety scores, and higher depression scores than those with no/mild dizziness. Cadence during gait was also associated with the level of dizziness reported.

Association Between Collision Sport Career Duration and Gait Performance in Male Collegiate Student-Athletes

BACKGROUND

Investigations of estimated age of first exposure to repetitive head impacts from collision and contact sports have shown no associations with neurocognitive or neurobehavioral function at the collegiate level, but the effect of career duration may be a more comprehensive factor. Understanding whether longer career duration influences gait performance would provide insights into potential neurological impairment.

PURPOSE

To examine the relationship between career duration of collision sports and single/dual-task gait performance in collegiate student-athletes.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We recruited 168 male student-athletes from collision sports: football, lacrosse, ice hockey, and wrestling (mean ± SD age, 19.2 ± 1.3 years; height, 184.5 ± 7.2 cm; mass, 94.3 ± 15.9 kg; estimated age of first exposure, 8.6 ± 3.1 years; career duration, 10.6 ± 3.0 years). All participants completed a baseline single- and dual-task gait assessment before the start of their athletic season. Inertial measurement units were used to measure gait speed and stride length. During the dual task, participants were asked to perform working memory cognitive tasks while walking. The dependent variables were single/dual-task gait speed and stride length, cognitive accuracy, and dual-task cost. The relationship between career duration, analyzed as a continuous variable, and the dependent variables was analyzed using a linear regression.

RESULTS

There were no significant associations between career duration and single-task gait speed (1.16 ± 0.16 m/s; β = -0.004; P = .35; 95% CI = -0.012 to 0.004; η² = 0.005) or dual-task gait speed (1.02 ± 0.17 m/s; β = -0.003; P = .57; 95% CI = -0.011 to 0.006; η² = 0.002). There were also no significant associations between career duration and single/dual-task stride length, cognitive accuracy, or dual-task cost.

CONCLUSION

Career duration among collegiate collision sport athletes was not associated with single- or dual-task gait performance, suggesting that a greater exposure to repetitive head impacts is not detrimental to dynamic postural control at the college level. However, the effects of diminished gait performance over the lifetime remain to be elucidated.

Comparison of pre-high school and high school football quarterback injuries

OBJECTIVE

To compare the common injuries of pre-high school American football quarterbacks (Pre-HS QBs) and high school American football quarterbacks (HS QBs) within the last 15 years.

METHODS

A retrospective chart review was performed at a sports medicine clinic at a tertiary-level pediatric medical center. Pediatric and adolescent American football quarterback patients who sustained sports-related injuries were extracted. Injury status (acute vs. overuse), injured anatomic locations, injury types, and surgical status were compared by Pre-HS QBs (<14 years old) and HS QBs (14-18 years old).

RESULTS

A total of 121 injuries were found in 118 male Pre-HS QBs (mean age: 12.4 ± 1.6), while 302 injuries were observed in 256 male HS QBs (mean age: 15.8 ± 1.4). Overall, nearly two-third (2/3) of injuries were acute (64.3%) while a little over one-third (1/3) of injuries were overuse in nature (35.7%), and there were no differences between Pre-HS and HS QBs (58.7% vs. 66.7%, p = 0.114). The top 3 injured anatomic locations for Pre-HS QBs were elbow (20.7%), shoulder (18.2%), and head/neck (14.0%). For HS QBs, the top 3 injured anatomic locations were shoulder (24.5%), knee (17.5%), and head/neck (15.2%). There were significant differences in proportion of elbow (20.7% vs. 10.6%, p = 0.006), hip/trunk/upper leg (10.7% vs. 3.3%, p = 0.002), and knee injuries (9.1% vs. 17.5%, p = 0.028) between Pre-HS and HS QBs. Pre-HS QBs had significantly more bony/cartilaginous/labral injuries than their older counterparts (60.3% vs. 46.3%, p = 0.009) while HS QBs experienced significantly more ligamentous injuries than Pre-HS QBs (14.2% vs. 5.8%, p = 0.015).

CONCLUSIONS

QB-associated injuries were distinctively different between Pre-HS and HS QBs. Future studies are warranted to investigate relatively high proportions of elbow injuries as well as bony/cartilaginous/labral injuries found in Pre-HS QBs.

Transition-Related Psychosocial Factors and Mental Health Outcomes in Former National Football League Players: An NFL-LONG Study

Transition from professional sport to nonsport endeavors has implications for postcareer health and well-being of athletes. The purpose of the current study was to examine associations among transition-related psychosocial factors and current mental health outcomes in former National Football League (NFL) players. Participants were former NFL players (n = 1,784; mean age = 52.3 ± 16.3 years) who responded to a questionnaire assessing the nature of their discontinuation from professional football (i.e., any degree of voluntary choice vs. forced discontinuation), prediscontinuation transition planning (yes vs. no), and current symptoms of depression and anxiety. After adjusting for relevant covariates, having an involuntary discontinuation and no transition plan prior to discontinuation were associated with greater depressive and anxiety symptom severity. Autonomy in discontinuation and pretransition planning are important to former NFL football players' mental health. Increasing autonomy in the discontinuation decision and pretransition planning represent psychoeducational intervention targets for this population.

Longitudinal trajectory of depression symptom severity and the influence of concussion history and physical function over a 19-year period among former National Football League (NFL) players: an NFL-LONG Study

OBJECTIVE

This study investigated the longitudinal course of depressive symptom severity over 19 years in former American football players and the influence of concussion history, contact sport participation and physical function on observed trajectories.

METHODS

Former American football players completed a general health questionnaire involving demographic information, medical/psychiatric history, concussion/football history and validated measures of depression and physical function at three time points (2001, 2010 and 2019). Parallel process latent growth curve modelling tested associations between concussion history, years of football participation, and overall and change in physical function on the overall level and trajectory of depressive symptoms.

RESULTS

Among the 333 participants (mean(SD) age, 48.95 (9.37) at enrolment), there was a statistically significant, but small increase in depressive symptom severity from 2001 (48.34 (7.75)) to 2019 (49.77 (9.52)), slope=0.079 (SE=0.11), p=0.007. Those with greater concussion history endorsed greater overall depressive symptom severity, B=1.38 (SE=0.33), p<0.001. Concussion history, B<0.001 (SE=0.02), p=0.997 and years of participation, B<0.001 (SE=0.01), p=0.980, were not associated with rate of change (slope factor) over 19 years. Greater decline in physical function, B=-0.71 (SE=0.16), p<0.001, was predictive of a faster growth rate (ie, steeper increase) of depression symptom endorsement over time.

CONCLUSIONS

Concussion history, not years of participation, was associated with greater depressive symptom severity. Neither factor was predictive of changes over a 19-year period. Decline in physical function was a significant predictor of a steeper trajectory of increased depressive symptoms, independent of concussion effects. This represents one viable target for preventative intervention to mitigate long-term neuropsychiatric difficulties associated with concussion across subsequent decades of life.

Proteomic Discovery of Noninvasive Biomarkers Associated With Sport-Related Concussions

BACKGROUND AND OBJECTIVES

Sport-related concussions affect millions of individuals across the United States each year, and current techniques to diagnose and monitor them rely largely on subjective measures. Our goal was to discover and validate objective, quantifiable noninvasive biomarkers with the potential to be used in sport-related concussion diagnosis.

METHODS

Urine samples from a convenience series of healthy control collegiate athletes who had not sustained a concussion and athletes who sustained a concussion as diagnosed by a sports medicine physician within 7 days were collected prospectively and studied. Participants also completed an instrumented single-task gait analysis as a functional measure. Participants were recruited from a single collegiate athletic program and were ≥18 years of age and were excluded if they had a concomitant injury, active psychiatric conditions, or preexisting neurologic disorders. Using Tandem Mass Tags (TMT) mass spectroscopy and ELISA, we identified and validated urinary biomarkers of concussion.

RESULTS

Forty-eight control and 47 age- and sex-matched athletes with concussion were included in the study (51.6% female, 48.4% male, average age 19.6 years). Participants represented both contact and noncontact sports. All but 1 of the postconcussion participants reported experiencing symptoms at the time of data collection. Insulin-like growth factor 1 (IGF-1) and IGF binding protein 5 (IGFBP5) were downregulated in the urine of athletes with concussions compared to healthy controls. Multivariable risk algorithms developed to predict the probability of sport-related concussion showed that IGF-1 multiplexed with single-task gait velocity predicts concussion risk across a range of postinjury time points (area under the curve [AUC] 0.786, 95% confidence interval [CI] 0.690-0.884). When IGF-1 and IGFBP5 are multiplexed with single-task gait velocity, they accurately distinguish between healthy controls and individuals with concussion at acute time points (AUC 0.835, 95% CI 0.701-0.968, p < 0.001).

DISCUSSION

These noninvasive biomarkers, discovered in an objective and validated manner, may be useful in diagnosing and monitoring sport-related concussions in both acute phases of injury and several days after injury.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02354469 (submitted February 2015, first patient enrolled August 2015).

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that urinary IGF-1 and IGFBP5 multiplexed with single-task gait velocity may be useful in diagnosing sport-related concussion.

Titrating the Translational Relevance of a Low-Level Repetitive Head Impact Model

Recently, there has been increased attention in the scientific community to the phenomenon of sub-concussive impacts, those hits to the head that do not cause the signs and symptoms of a concussion. Some authors suggest that sub-concussive impacts may alter behavior and cognition, if sustained repetitively, but the mechanisms underlying these changes are not well-defined. Here, we adapt our well-established weight drop model of repetitive mild traumatic brain injury (rmTBI) to attempt to produce a model of low-level repetitive head impacts (RHI). The model was modified to eliminate differences in latency to right following impact and gross behavioral changes after a single cluster of hits. Further, we varied our model in terms of repetition of impact over a 4-h span to mimic the repeated sub-concussive impacts that may be experienced by an athlete within a single day of play. To understand the effects of a single cluster of RHIs, as well as the effect of an increased impact frequency within the cluster, we evaluated classical behavioral measures, serum biomarkers, cortical protein quantification, and immunohistochemistry both acutely and sub-acutely following the impacts. In the absence of gross behavioral changes, the impact protocol did generate pathology, in a dose-dependent fashion, in the brain. Evaluation of serum biomarkers revealed limited changes in GFAP and NF-L, which suggests that their diagnostic utility may not emerge until the exposure to low-level head impacts reaches a certain threshold. Robust decreases in both IL-1β and IL-6 were observed in the serum and the cortex, indicating downregulation of inflammatory pathways. These experiments yield initial data on pathology and biomarkers in a mouse model of low-level RHIs, with relevance to sports settings, providing a starting point for further exploration of the potential role of anti-inflammatory processes in low-level RHI outcomes, and how these markers may evolve with repeated exposure.