Elucidating differences in concussion subtype symptomatology in sports-related versus non-sports-related concussions: a retrospective cohort study.

OBJECTIVE: Postconcussive symptom questionnaires (PCSQs) are often used in concussion patient assessment, yet there is a lack of knowledge as to whether symptom subtype prevalence is dependent on the mechanism of injury (MOI). These subtypes can be defined as cognitive, atlanto-occipital/cervical spine, autonomic, balance, low energy/fatigue/sleep, emotional changes, eyes, and somatic. Using an institutional PCSQ that quantitatively addressed these subtypes, this retrospective study aimed to provide insight into differences in subtype symptomatology between sports-related (SR) and non-sports-related (NSR) injuries. METHODS: Consecutive concussion patients with Glasgow Coma Scale (GCS) score ≥ 13 and ≥ 16 years of age who were treated at a concussion clinic affiliated with an academic level I trauma center in the United States between December 2009 and January 2020 were eligible for inclusion. The authors extracted data on MOI, comorbidities, habits, prior injuries, and PCSQ results. Multivariate analysis of covariance was then conducted to determine the correlations between subtype scores and MOI while considering covariates. RESULTS: Of the 194 patients remaining after applying inclusion and exclusion criteria, analysis included 91 patients in the SR group consisting of 54 (59%) males with mean ± SD (range) age of 20.9 ± 7.3 (16-58) years and 103 patients in the NSR group consisting of 38 (37%) males with mean age of 39.2 ± 14.8 (17-71) years. Demographic characteristics differed significantly between groups. Estimated marginal mean scores were significantly lower in the SR injury group compared to the NSR injury group (with comparing main effects) for the cognitive (p < 0.001), autonomic (p < 0.000), balance (p < 0.025), energy (p < 0.006), emotional (p < 0.000), and total score (p < 0.001) subtypes. Multivariate tests identified three comorbidities that contributed to differences in subtype scores between groups: migraines (p < 0.012), vertigo (p < 0.004), and anxiety (p < 0.038). No significant results were found for the remaining comorbidities of (but not limited to) depression, neuropsychiatric disorders, seizures, syncope, sleep disorder, or none. CONCLUSIONS: The findings indicate that patients who sustain a concussion via an NSR injury present with more severe symptoms but similar concussion subtype frequency as those presenting with SR concussion. This suggests that the MOI may correlate more closely to symptom severity than concussion subtype composition, although larger patient populations with more definitive control of MOI are needed to further elucidate these claims.

Physiological Monitoring Detected Changes During Women's Soccer Anterior Cruciate Ligament Injury.

A growing number of studies utilizing wearable technologies are examining the influence of the autonomic nervous system (ANS) on intense training, recovery, and injury risk. Exercise biometric (EB) data were collected on collegiate, female soccer players during a preseason camp. One player sustained an anterior cruciate ligament (ACL) injury. Baseline anthropometric and EB data were compared to non-injured, position-matched teammates. All players had similar baseline testing. The injured athlete had a higher body mass index (BMI) and slower vision reaction time (RT). On the day of her injury (DOI), relative percentage heart rate recovery (tHRR) between intense training sets was calculated. Relative percentage tHRR was much lower for the injured athlete, indicating reduced recovery between training sets immediately prior to the injury. Also on DOI, the injured athlete had a lower glomerular filtration rate (GFR). In addition to BMI and RT differences, the lower relative percentage tHRR and GFR on the DOI observed for the injured athlete may reflect an imbalanced ANS recovery, and potentially to risk factors leading to her ACL injury.

American Football Players in Preseason Training at Risk of Acute Kidney Injury Without Signs of Rhabdomyolysis.

OBJECTIVE: This study was designed to identify changes in blood biomarkers that would indicate excessive muscle breakdown during the initial 10 days of preseason training in collegiate American football players and subsequently increase their risk of acute kidney injury (AKI). DESIGN: Prospective cohort study. SETTING: Preseason, heat acclimatization period. PARTICIPANTS: Twenty-five Division I American football players. INTERVENTION: Clinical biomarkers for muscle damage were measured during a preseason training camp. Samples were obtained before camp and approximately 5 and 10 days into camp after completion of heat acclimatization training. MAIN OUTCOMES: Creatine kinase, myoglobin, lactate dehydrogenase, and creatinine were measured. Glomerular filtration rate (GFR) was calculated. Urine was collected at each blood draw to qualitatively identify hematuria and red blood cells. RESULTS: A high percentage of athletes had an asymptomatic reduction in kidney function over the 10-day period. Ten of 23 athletes did have a significant, 31.6%, mean reduction in GFR, placing each at risk of AKI according to Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification. The plasma myoglobin for the at risk of AKI group had a mean value 8× above their baseline mean on day 5 and statistically significant mean 13× higher on day 10 than baseline. The not at risk of AKI group did not have significant differences between days 0, 5, and 10. CONCLUSIONS: A relatively high percentage of athletes had an asymptomatic reduction in kidney function during the intense preseason training period. 43.4% of athletes in this study had a significant 31.6% mean reduction in GFR over the 10 days. According to RIFLE classification, this placed each athlete "at risk" of AKI.

Lack of eye discipline during headers in high school girls soccer: A possible mechanism for increased concussion rates.

The sport of soccer is the fastest growing and most popular sport worldwide. With this growth and popularity, attention needs to be given to this athletic population. Sports related concussions is a topic that has gained attention both in the media and by governmental organizations, with growing initiatives in diagnosis, prevention and treatment. The act of soccer heading is thought to contribute to increased concussion incidence. Current evidence reveals that within the high school soccer athletic population, female athletes incur a higher concussion rate than males. This is often attributed to many things including differing cervical spinal musculature, skull thickness, etc., but a definitive reason has not yet been found. Other behaviors, such as field awareness and eye discipline™ on the field of play, may also be contributing factors that result in females incurring a greater concussion rate than males. For the purposes of this paper we define eye discipline™ as the ability to keep the eyes engaged in sporting activity with high risk potential. We present our hypothesis that high school female soccer players are more likely to have their eyes closed when in position for heading the ball as compared to high school male soccer players and this lack of visual awareness may increase the risk of concussion. Should these differences be substantiated between males and females, it may initiate and promote discussion of the need for vision training in the high school athletic setting. As a tool for injury prevention, vision training may improve specific visual parameters improving athletes' abilities to process the field of play and prepare for or avoid injury causing situations. Through ocular motor and visual conditioning, an athlete may become more eye disciplined™, and more likely to have their eyes open during heading of the ball, and more likely to avoid concussions.

Analysis of Central and Peripheral Vision Reaction Times in Patients With Postconcussion Visual Dysfunction.

OBJECTIVE: To determine whether central and peripheral vision reaction times (PVRTs) are prolonged in patients with visual dysfunction after sustaining a concussion. DESIGN: Comparison of Dynavision D2 central and PVRTs in patients with postconcussion visual dysfunction were compared with control data from a normative patient database. Concussion patients without visual dysfunction were not included in this study. SETTING: National Collegiate Athletic Association Division 1 college training room and university based, academic health center. PARTICIPANTS: Patients were selected for inclusion based on diagnosis of new visual dysfunction as indicated either by physical examination of the team physician or by patient self-report of symptoms. Patients included college athletes, college students, and concussion patient's presenting to a university based, academic health center. INTERVENTION: Measurement of central and PVRTs using a Dynavision D2 reaction time program were used as the dependent variables. Evaluations were conducted from 3 days to 11 months postconcussion, depending on the temporal development of visual symptoms after the concussion. No intervention was used. MAIN OUTCOME MEASURES: Average central and PVRTs for patients with postconcussion visual symptoms were compared with an asymptomatic control group with no history of concussion. RESULTS: Both central and PVRTs were significantly prolonged in patients with postconcussion visual symptoms compared with patients with no history of concussion. CONCLUSIONS: Central and PVRTs are both prolonged in patients with postconcussion visual dysfunction with PVRT being disproportionately prolonged. The percent change from central to PVRT was also increased in patients with postconcussion visual dysfunction.

A Novel Mass-Spring-Damper Model Analysis to Identify Landing Deficits in Athletes Returning to Sport After Anterior Cruciate Ligament Reconstruction.

Schneider, DK, Gokeler, A, Otten, E, Ford, KR, Hewett, TE, Divine, JG, Colosimo, AJ, Heidt, RS, and Myer, GD. A Novel mass-spring-damper model analysis to identify landing deficits in athletes returning to sport after anterior cruciate ligament reconstruction. J Strength Cond Res 31(9): 2590-2598, 2017-A mass-spring-damper (MSD) model may serve as an extension of biomechanical data from 3-dimensional motion analysis and epidemiological data which helps to delineate populations at risk for anterior cruciate ligament (ACL) injuries. The purpose of this study was to evaluate such a model. Thirty-six ACL reconstruction (ACLR) group subjects and 67 controls (CTRL) completed single-leg drop landing and single-leg broad jump tasks. Landing ground reaction force data were collected and analyzed with an MSD model. Medians, interquartile ranges, and limb symmetry indices (LSIs) were calculated and comparisons were made within and between groups. During a single-leg drop landing, the ACLR group had a lower spring LSI than the CTRL group (p = 0.015) and landed with decreased stiffness in the involved limb relative to the uninvolved limb (p = 0.021). The ACLR group also had an increased damping LSI relative to the CTRL group (p = 0.045). The ACLR subjects landed with increased stiffness (p = 0.006) and decreased damping (p = 0.003) in their involved limbs compared to CTRL subjects' nondominant limbs. During a single-leg forward broad jump, the ACLR group had a greater spring LSI value than the CTRL group (p = 0.045). The CTRL group also recorded decreased damping values in their nondominant limbs compared with the involved limbs of the ACLR group (p = 0.046). Athletes who have undergone ACLR display different lower-limb dynamics than healthy controls, according to an MSD model. Quadriceps dominance and leg dominance are components of ACLR athletes' landing strategies and may be identified with an MSD model and addressed during rehabilitation.

Can a transient exertion-related carotid (TERC) murmur heard during a symptom-limited exercise test be used as a means for managing sports concussion?

We hypothesize that a transient exertion-related carotid (TERC) murmur flow murmur similar in nature to a "bruit" heard best at the carotid artery during exercise in healthy individuals can be used as a means for assessing post-concussion injury exertion tolerance. Typically there are no arterial sounds heard at the carotid artery in healthy individuals. Bruit, heard at rest, is an indicator of cardiovascular disease. Listening for a flow murmur or bruit-like sounds during exercise may indicate brain blood flow autoregulation and that this audible change in brain blood flow autoregulation could be used to assess exercise tolerance. We present very preliminary evidence supporting our hypothesis in that a transient exertion-related carotid (TERC) murmur is heard at a HR (HR) of approximately 150 beats per minute (bpm) in healthy individuals and 120bpm in concussion patients. Future prospective clinical studies to validate this hypothesis and these methods may aid clinicians who manage concussion patients by using this method to help guide exertion protocols.

Utilization of modified NFL combine testing to identify functional deficits in athletes following ACL reconstruction.

STUDY DESIGN: Case control. OBJECTIVES: To use modified NFL Combine testing methodology to test for functional deficits in athletes following anterior cruciate ligament (ACL) reconstruction following return to sport. BACKGROUND: There is a need to develop objective, performance-based, on-field assessment methods designed to identify potential lower extremity performance deficits and related impairments in this population. METHODS: Eighteen patients (mean ± SD age, 16.9 ± 2.1 years; height, 170.0 ± 8.7 cm; body mass, 71.9 ± 21.8 kg) who returned to their sport within a year following ACL reconstruction (95% CI: 7.8 to 11.9 months from surgery) participated (ACLR group). These individuals were asked to bring 1 or 2 teammates to serve as control participants, who were matched for sex, sport, and age (n = 20; mean ± SD age, 16.9 ± 1.1 years; height, 169.7 ± 8.4 cm; body mass, 70.1 ± 20.7 kg). Functional performance was tested using the broad jump, vertical jump, modified long shuttle, modified pro shuttle, modified agility T-test, timed hop, triple hop, single hop, and crossover hop tests. A 1-way multivariate analysis of variance (MANOVA) was used to evaluate group differences for dependent performance variables. RESULTS: The functional performance measurements of skills requiring bilateral involvement of both lower extremities showed no group differences between the ACLR and control groups (P>.05). An overall group difference (P = .006) was observed for the combined limb symmetry index (LSI) measures. However, the modified double-limb performance tasks (long shuttle, modified agility T-test, and pro shuttle) were not, independently, sufficiently sensitive to detect limb deficits in individuals with ACL reconstruction. Conversely, the LSI on the distance measures of the single-limb performance tasks all provided moderate to large effect sizes to differentiate between the ACLR and control groups, as the individuals who had ACL reconstruction demonstrated involved limb deficits on all measures (P<.05). Finally, the LSI for the timed hop test was not different between groups (P>.05). CONCLUSIONS: These findings indicate that, while unilateral deficits are present in individuals following ACL reconstruction, they may not be evident during bipedal performance or during modified versions of double-limb performance activities. Isolation of the involved limb with unilateral hopping tasks should be used to identify deficits in performance.

Use of viscosupplementation for knee osteoarthritis: an update.

Because of the rising numbers of patients affected by osteoarthritis (OA), management decisions on how to minimize pain and improve function in OA patients are important. Intra-articular hyaluronic acid (IAHA) knee injections have become a common treatment in the management of knee OA. In an editorial appearing in the 2007 National Knowledge Week on Osteoarthritis: National Health Service Evidence, four questions were asked about the clinical use of IAHA treatment for OA: 1) Who is the ideal candidate for HA viscosupplementation? 2) Do the mechanical and biological effects differ in importance in different stages of the disease? 3) What is the ideal dose in early- and late-stage OA? 4) Can the biological effect be delivered by means other than injection? These key issues are addressed. On the basis of results from several systemic reviews and meta-analyses, we conclude that IAHA knee injections in patients with knee OA result in modest improvements when measured by validated outcomes.

The incidence and potential pathomechanics of patellofemoral pain in female athletes.

BACKGROUND: The aims of this study were to determine the prevalence and incidence of patellofemoral pain (PFP) in young female athletes and prospectively evaluate measures of frontal plane knee loading during landing to determine their relationship to development of PFP. We hypothesized that increased dynamic knee abduction measured during preseason biomechanical testing would be increased in those who developed PFP relative to teammates who did not develop PFP. METHODS: Middle and high school female athletes (n=240) were evaluated by a physician for PFP and for landing biomechanics prior to their basketball season. The athletes were monitored for athletic exposures and PFP injury during their competitive seasons. FINDINGS: At the beginning of the season, the point prevalence of PFP was 16.3 per 100 athletes. The cumulative incidence risk and rate for the development of new unilateral PFP was 9.66 per 100 athletes and 1.09 per 1000 athletic exposures, respectively. All new PFPs developed in middle school athletes who demonstrated mean International Knee Documentation Committee score of 85.6+/-7.7 at diagnosis. The new PFP group demonstrated increased knee abduction moments at initial contact (95% CI: 0.32 to 4.62Nm) on the most-symptomatic limb and maximum (95% CI: 1.3 to 10.1Nm; P=0.02) on the least-symptomatic (or no symptoms) limb relative to the matched control limbs. Knee abduction moments remained increased in the new PFP group when normalized to body mass (P<0.05). INTERPRETATION: The increased knee abduction landing mechanics in the new PFP group indicate that frontal plane loads contribute to increased incidence of PFP.

Longitudinal assessment of noncontact anterior cruciate ligament injury risk factors during maturation in a female athlete: a case report.

OBJECTIVE: To present a unique case of a young pubertal female athlete who was prospectively monitored for previously identified anterior cruciate ligament (ACL) injury risk factors for 3 years before sustaining an ACL injury. BACKGROUND: In prospective studies, previous investigators have examined cross-sectional measures of anatomic, hormonal, and biomechanical risk factors for ACL injury in young female athletes. In this report, we offer a longitudinal example of measured risk factors as the participant matured. DIFFERENTIAL DIAGNOSIS: Partial or complete tear of the ACL. MEASUREMENTS: The participant was identified from a cohort monitored from 2002 until 2007. No injury prevention training or intervention was included during this time in the study cohort. FINDINGS: The injury occurred in the year after the third assessment during the athlete's club basketball season. Knee examination, magnetic resonance imaging findings, and arthroscopic evaluation confirmed a complete ACL rupture. The athlete was early pubertal in year 1 of the study and pubertal during the next 2 years; menarche occurred at age 12 years. At the time of injury, she was 14.25 years old and postpubertal, with closing femoral and tibial physes. For each of the 3 years before injury, she demonstrated incremental increases in height, body mass index, and anterior knee laxity. She also displayed decreased hip abduction and knee flexor strength, concomitant with increased knee abduction loads, after each year of growth. CONCLUSIONS: During puberty, the participant increased body mass and height of the center of mass without matching increases in hip and knee strength. The lack of strength and neuromuscular adaptation to match the increased demands of her pubertal stature may underlie the increased knee abduction loads measured at each annual visit and may have predisposed her to increased risk of ACL injury.

The healing potential of stable juvenile osteochondritis dissecans knee lesions.

BACKGROUND: The purpose of the present study was to determine if patient age, lesion size, lesion location, presenting knee symptoms, and sex predict the healing status after six months of a standard protocol of nonoperative treatment for stable juvenile osteochondritis dissecans of the knee. METHODS: Forty-two skeletally immature patients (forty-seven knees) who presented with a stable osteochondritis dissecans lesion were included in the present study. All patients were managed with temporary immobilization followed by knee bracing and activity restriction. The primary outcome measure of progressive lesion reossification was determined from serial radiographs every six weeks, for up to six months of nonoperative treatment. A multivariable logistic regression model was used to determine potential predictors of healing status from the listed independent variables. RESULTS: After six months of nonoperative treatment, sixteen (34%) of forty-seven stable lesions had failed to progress toward healing. The mean surface area (and standard deviation) of the lesions that showed progression toward healing (208.7 +/- 135.4 mm(2)) was significantly smaller than that of the lesions that failed to show progression toward healing (288.0 +/- 102.6 mm(2)) (p = 0.05). A logistic regression model that included patient age, normalized lesion size (relative to the femoral condyle), and presenting symptoms (giving-way, swelling, locking, or clicking) was predictive of healing status. Age was not a significant contributor to the predictive model (p = 0.25). CONCLUSIONS: In two-thirds of immature patients, six months of nonoperative treatment that includes activity modification and immobilization results in progressive healing of stable osteochondritis dissecans lesions. Lesions with an increased size and associated swelling and/or mechanical symptoms at presentation are less likely to heal.

MRI appearance of chronic stress injury of the iliac crest apophysis in adolescent athletes.

OBJECTIVE: The objective of our study was to describe the MRI appearance of chronic repetitive stress injury of the iliac crest apophysis in adolescent athletes. CONCLUSION: Increased signal intensity on water-sensitive sequences and mild widening of the physis, often with adjacent bone marrow and muscle edema, are characteristic of chronic stress injury of the iliac apophysis in adolescent athletes who may present with hip, pelvic, or back pain.

Predictors of sprint start speed: the effects of resistive ground-based vs. inclined treadmill training.

There is currently no consensus with regard to the most effective method to train for improved acceleration, or with regard to which kinematic variable provides the greatest opportunity for improvement in this important performance characteristic. The purpose of this study was to determine the effects of resistive ground-based speed training and incline treadmill speed training on speed-related kinematic measures and sprint start speed. The hypothesis tested was that incline treadmill training would improve sprint start time, while the ground-based resistive training would not. Corollary hypotheses were that treadmill training would increase stride frequency and ground-based training would not affect kinematics during the sprint start. Thirty-one high school female soccer players (15.7 +/- 0.5 years) were assigned to either treadmill (n = 17) or ground-based (n = 14) training groups and trained 2 times a week for 6 weeks. The treadmill group utilized incline speed training on a treadmill, while the ground-based group utilized partner band resistance ground-based techniques. Three-dimensional motion analysis was used (4.5 m mark) before and after training to quantify kinematics during the fastest of 3 recorded sprint starts (9.1 m). Both groups decreased average sprint start time from 1.75 +/- 0.12 to 1.68 +/- 0.08 seconds (p < 0.001). Training increased stride frequency (p = 0.030) but not stride length. After training, total vertical pelvic displacement and stride length predicted 62% of the variance in sprint start time for the resistive ground-based group, while stride length and stride frequency accounted for 67% prediction of the variance in sprint start time for the treadmill group. The results of this study indicate that both incline treadmill and resistive ground-based training are effective at improving sprint start speed, although they potentially do so through differing mechanisms.

Viscosupplementation for knee osteoarthritis: a systematic review.

Due to the rising number of patients affected by osteoarthritis (OA), appropriate management decisions for minimizing pain and improving physical function for patients with OA are important. Hyaluronic acid (HA) knee injections have become a common tool for the management of OA of the knee, and the number of randomized controlled trials on the efficacy and safety of this treatment is growing. We performed a systematic review of the five published meta-analyses, which include single- or double-blinded randomized trials performed at one center or multiple centers (Level I evidence). Within each meta-analysis, a quality assessment tool for each trial was used based on outcome measures of OA-related pain, disease severity, trial period, and mean efficacy. We analyzed and compared the data collection and qualitative analysis methods, outcomes, and conclusions presented for each meta-analysis. Although they used different strategies, each used scientifically sound methods for analysis of many of the same trials; however, each used a different measure of trial quality and heterogeneity. Despite these differences, all come to a similar conclusion that when the strictest quality tools and interpretation of heterogeneity are used, Level I evidence demonstrates that the use of HA in patients with OA results in modest improvement in validated outcomes.

Valgus bracing for degenerative knee osteoarthritis: relieving pain, improving gait, and increasing activity.

Pain from osteoarthritis, the leading cause of disability in older patients, affects gait mechanics. Wearing an unloading brace may improve gait symmetry, decrease symptomatic pain, and increase activity for patients who have osteoarthritis of the knee or other varus knee deformities. Brace use may contribute to improved knee proprioception, gait parameters, and pain scores. Clinicians can recommend a trial of brace wear for patients who have knee pain as a conservative measure or to provide temporary pain relief before joint replacement surgery.

The incidence, risk factors, and clinical manifestations of hyponatremia in marathon runners.

OBJECTIVE: To report on the incidence, identify the risk factors, and clarify the clinical manifestations of acute hyponatremia in marathon runners. DESIGN: An observational and retrospective case-controlled series. SETTING: The medical care area of the 2000 Houston Marathon. PATIENTS: Marathon finishers treated in medical area receiving intravenous fluids (N=55), including a more detailed analysis of 39 runners completing a retrospective questionnaire. MAIN OUTCOME MEASURES: Vital signs, serum electrolytes, and finish time were analyzed via ANOVA studies between all non-hyponatremic (NH: N=34)) and hyponatremic (H: N=21)) runners. Fluid intake, training variables, NSAID use, and Symptomatology were further analyzed to delineate all significant differences between groups. RESULTS: There were no significant differences in vital signs, training variables, or NSAID use between H and NH groups, although there was a trend towards the less experienced runners presenting with lower post-race sodium levels. H runners had lower potassium [K] (p=.04), chloride [Cl] (p<.001), and blood urea nitrogen [BUN] (p=.004) levels than NH runners. There was a significant inverse linear relationship between both finish time versus [Na] (r2 =.51) and total amount of fluid ingested versus [Na] (r2 =.39). The total cups of water (p=.004), electrolyte/carbohydrate solution (p=.005) and total amount of fluid ingested (p<.001) were significantly higher in H compared to NH runners and the degree of hyponatremia was related in a dose dependent manner. Vomiting was observed more frequently in H than NH runners (p=.03). CONCLUSION: 21 runners presented to the medical area of the Houston Marathon with hyponatremia (.31% of entrants). Excessive fluid consumption and longer finishing times were the primary risk factors for developing this condition. Vomiting was the only clinical sign differentiating hyponatremia from other conditions that induce exercise-associated collapse.