Quantitative Analysis of Ball-Head Impact Exposure in Youth Soccer Players.

Since the implementation of the US Soccer heading guidelines released in 2015, little to no research on ball-head impact exposure in the United States youth soccer population has been conducted. The purpose was to compare ball-head impact exposure across sex and age in youth soccer players over a weekend tournament. Ten male and female games for each age group (Under-12 [U12], U13, and U14) were video recorded at a weekend tournament for a total of 60 games. Ball-head impact exposure for each game was then coded following a review of each recording. Male players were 2.8 times more likely to have ball-head impacts than female players, (p < 0.001) particularly in the U14 age group when compared to the U12 age group (p = 0.012). Overall 92.4% of players experienced 0-1 ball-head impacts per game with the remaining players experiencing 2+ ball-head impacts per game. Ball-head impact exposure levels are low in the youth players. Most youth soccer players do not head the soccer ball during match play and those that did, only headed the ball on average once per game. Overall, the difference in ball-head impact exposure per player was less than 1 between all the groups, which may have no clinical meaning.

Examining the influence of the Get aHEAD Safely in Soccer™ program on head impact kinematics and neck strength in female youth soccer players.

The objective was to examine the efficacy of the Get aHEAD Safely in Soccer™ intervention on head impact kinematics and neck strength in female youth soccer players. The control group (CG) consisted of 13 players (age: 11.0 ± 0.4 yrs), while the experimental group (EG) consisted of 14 players (age: 10.6 ± 0.5 yrs). Head impact kinematics included peak linear acceleration (PLA), peak rotational acceleration (PRA), and peak rotational velocity (PRV). Pre- and post-season measures included strength measures of neck/torso flexion (NF/TF) and extension (NE/TE). Data were analysed using a multilevel linear model and ANOVA techniques. No differences in PLA, PRA, or PRV were observed between groups. The EG showed significant improvement in NF strength while the CG showed significant improvement in NE strength. Both groups significantly improved in TF pre- to post-season. The foundational strength components of the Get aHEAD Safely in Soccer program appear to show a benefit in youth soccer players beginning to learn the skill of purposeful heading.

Postural Control Deficits After Repetitive Soccer Heading.

OBJECTIVE: To determine the acute effects of repetitive soccer heading on postural control. DESIGN: Prospective study; participants were divided into 2 groups: a soccer heading group and a control group. SETTING: Biomechanics laboratory. PARTICIPANTS: One hundred sixty participants, including youth (age = 13.0 ± 0.8 years), high school (age = 17.2 ± 1.0 years), and collegiate (age = 20.2 ± 1.3 years) male and female soccer players, participated in this study. INTERVENTIONS: Participants in the soccer heading group performed 12 soccer headers (initial velocity = 11.2 m/s). Postural control testing was performed both before (PRE) and immediately after (POST) the purposeful soccer headers. Control participants performed postural control testing PRE and POST a 15-minute wait period. During postural control testing, participants were asked to stand on the MobileMat (Tekscan Inc, Boston, Massachusetts) for two 2-minute intervals with their hands on their hips and their feet together with one eyes-open and one eyes-closed trial. MAIN OUTCOME MEASURES: Using the center-of-pressure data, 95% area, sway velocity, and ApEn were calculated. Multilevel linear models were used to analyze the effects of age, sex, group, condition, and concussion history simultaneously. RESULTS: Participants in the soccer heading group had significantly higher sway velocity POST than participants in the control group after controlling for age, sex, concussion history, condition, and PRE (t = -3.002; P = 0.003; 95% confidence interval, -0.482 to -0.100). There were no significant differences from PRE to POST for 95% area, M/L ApEn, and A/P ApEn. CONCLUSIONS: Repetitive soccer heading does not affect most postural control measures, even among youth athletes. However, sway velocity increased after heading relative to control participants independent of age, sex, and concussion history.

Development of Composite Scores for the TBI-QOL.

OBJECTIVE: To develop a set of composite scores that can be used for interpreting quality of life (QOL) after traumatic brain injury (TBI) using 9 of the patient-reported outcomes measures from the Traumatic Brain Injury Quality of Life (TBI-QOL) measurement system. DESIGN: Participants completed 20 item banks from the TBI-QOL as part of a larger assessment. Composite index scores were created with normalized transformation with nonlinear area conversion using scores from 9 of the banks, and are expressed in index score units, with higher composite scores indicating better functioning. For descriptive purposes, associations among composites and individual banks were evaluated using regression, along with patterns of composite scores by injury severity groups using analysis of variance. SETTING: Three medical centers in the United States. PARTICIPANTS: Community-dwelling adults (n=504) with a history of TBI. INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURE: TBI-QOL. RESULTS: Five composite indices were generated: global QOL, physical health, emotional health, cognitive health, and social health. Lookup tables are provided herein. Composite scores were highly intercorrelated (all r>.60, P<.0001), and individual TBI-QOL banks all correlate strongly with the global QOL composite in the expected direction (all r>.50, P<.0001). CONCLUSION: Researchers and clinicians can use the TBI-QOL global QOL, physical health, emotional health, cognitive health, and social health composite scores to aggregate results from multiple TBI-QOL banks, which is anticipated to ease interpretation and reliability. This work additionally highlights the importance of considering nonphysical symptoms as outcomes variables for TBI research, as cognitive, social, and emotional domains were some of the most strongly correlated banks with the global QOL composite.

Evaluating Postural Control and Ankle Laxity Between Taping and High-Top Cleats in High School Football Players.

CONTEXT: Lateral ankle sprains are the most common injuries in high school sports. While ankle taping is a preferred method of external prophylactic support, its restrictive properties decline during exercise. The Under Armour® Highlight cleat is marketed on the premise that it provides added support without the need for additional ankle taping. OBJECTIVE: To determine if differences in ankle joint laxity and postural control exist between football players wearing the Under Armour® Highlight cleat (Under Armour Inc, Baltimore, MD) as compared to a low/mid-top cleat with ankle tape. DESIGN: Crossover trial. SETTING: Athletic training room and football practice field sideline. PATIENTS: 32 interscholastic football players (15.8 ± 1.0 y; 178.9 ± 7.4 cm; 87.1 ± 21.4 kg). INTERVENTIONS: Ankle laxity was assessed using an instrumented ankle arthrometer (Blue Bay Research Inc, Milton, FL), while postural control testing was performed on the Tekscan MobileMat™ Balanced Error Scoring System (BESS; South Boston, MA). The 2 treatments included Under Armour® Highlight cleats and a low/mid-top cleat with ankle tape applied to the nondominant ankle only. Measurements were taken before and immediately after practice. MAIN OUTCOME MEASURES: The independent variable was treatment (Highlight vs low/mid-top cleat with ankle tape). Dependent variables included ankle arthrometry measures of anterior displacement (mm), inversion/eversion rotation (deg), and the modified BESS error scores. A linear mixed-effects model was used for analysis. RESULTS: The low/mid-top cleat with tape condition had significantly higher inversion range-of-motion (ROM) and inversion/eversion rotation postexercise when compared to the Highlight cleat (P < 0.05). CONCLUSIONS: The results of this study provide some evidence that the Under Armour® Highlight cleat restricts ankle ROM following a training session better than the taped low/mid-top cleat. Further study is warranted to determine if this high-top style of football cleat can reduce the incidence of ankle sprains and how it might compare to spat taping.

Sex and age differences in head acceleration during purposeful soccer heading.

Differences in head-neck segment mass, purposeful heading technique, and cervical strength and stiffness may contribute to differences in head accelerations across sex and age. The purpose of this study was to compare head acceleration across sex and age (youth [12-14 years old], high school and collegiate) during purposeful soccer heading. One-hundred soccer players (42 male, 58 female, 17.1 ± 3.5 years, 168.5 ± 20.3 cm, 61.5 ± 13.7 kg) completed 12 controlled soccer headers at an initial ball velocity of 11.2 m/s. Linear and rotational accelerations were measured using a triaxial accelerometer and gyroscope and were transformed to the head centre-of-mass. A MANOVA revealed a significant multivariate main effect for sex (Pillai's Trace = .165, F(2,91) = 11.868, p < .001), but not for age (Pillai's Trace = .033, F(4,182) = 0.646, p = .630). Peak linear and rotational accelerations were higher in females (40.9 ± 13.3 g; 3279 ± 1065 rad/s2) than males (27.6 ± 8.5 g, 2219 ± 823 rad/s2). These data suggest that under controlled soccer heading conditions, females may be exposed to higher head accelerations than males.

Assessing performance, stability, and cleat comfort/support in collegiate club soccer players using prophylactic ankle taping and bracing.

Soccer athletes at all levels of play are keenly aware of their equipment needs including cleat wear, and want to be protected from injury but without impeding on-field performance. Ankle injury is a common disorder that is prevalent in the sport of soccer and recent improvements in ankle prophylaxis interventions have proven effective. The aim of this study was to determine if the use of elastic taping or a neoprene sleeve alters performance, stability, and cleat comfort/support in soccer players compared to wearing a soccer cleat without any external support. Twenty male collegiate club soccer players were recruited and randomly assigned to the three conditions (untaped control, taped, neoprene sleeve). Performance testing and comfort/support assessment for each condition took place in one on-field test session, while stability testing was completed during a separate laboratory session. The only significant finding was improved inversion/eversion stability in both the tape and sleeve conditions as compared to the cleated condition. The addition of tape or a sleeve did not have an adverse effect on performance or comfort during functional and stability testing, and should therefore be considered as a method to decrease ankle injuries in soccer athletes as external supports provide increased stability in inversion/eversion range of motion.

Effects of Pre-Collegiate Sport Specialization on Cognitive, Postural, and Psychological Functions: Findings from the NCAA-DoD CARE Consortium.

BACKGROUND: Early sport specialization has been associated with an increased risk of musculoskeletal injuries and unfavorable psychological outcomes; however, it is unknown whether sport specialization is associated with worse cognitive, postural, and psychological functions in first-year collegiate student-athletes. METHODS: First-year collegiate multisport (MA) and single-sport (SA) student-athletes were identified using a pre-collegiate sport experience questionnaire. The cognitive, postural, and psychological functions were assessed by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and Brief Symptom Inventory 18 (BSI-18). RESULTS: MA student-athletes performed higher in cognitive outcomes (e.g., higher ImPACT visual memory composite scores [ß = 0.056, p < 0.001]), but had higher psychological distress (e.g., higher BSI-18 global severity index [ß = 0.057, p < 0.001]) and no difference in postural stability (p > 0.05) than SA student-athletes. CONCLUSIONS: This study indicated first-year collegiate athletes with a history of sport specialization demonstrate lower cognitive performance but decreased psychological distress and no differences in static postural stability as compared to their MA counterparts. Future studies should consider involving different health measures to better understand the influence of sport specialization on overall physical and mental health.

Internal (Factorial) Validity of the ANAM using a Cohort of Woman High-School Soccer Players.

INTRODUCTION: Computerized neuropsychological testing is a cornerstone of sport-related concussion assessment. Female soccer players are at an increased risk for concussion as well as exposures to repetitive head impacts from heading a soccer ball. Our primary aim was to examine factorial validity of the Automated Neuropsychological Assessment Metrics (ANAM) neuropsychological test battery in computing the multiple neurocognitive constructs it purports to measure in a large cohort of interscholastic female soccer players. METHODS: Study participants included 218 interscholastic female soccer players (age = 17.0±0.7 year; mass = 55.5±6.8 kg; height = 164.7±6.6 cm) drawn from a large (850+) prospective database examining purposeful heading from four area high schools over a 10-year period. The ANAM-2001 measured neurocognitive performance. Three methods were used to identify integral constructs underlying the ANAM: (a) exploratory factor analysis (EFA), (b) first-order confirmatory factor analysis (CFA), and (c) hierarchical CFA. RESULTS: Neuropsychological phenomena measured by the ANAM-2001 were best reproduced by a hierarchical CFA organization, composed of two lower level factors (Simple Reaction Time, Mental Efficiency) and a single, general composite. Although the ANAM was multidimensional, only the composite was found to possess sufficient construct dimensionality and reliability for clinical score interpretation. Findings failed to uphold suppositions that the ANAM measures seven distinct constructs, or that any of its seven tests provide unique information independent of other constructs, or the composite, to support individual interpretation. CONCLUSIONS: Outcomes infer the ANAM possesses factorial-validity evidence, but only scores from the composite appear to sufficiently internally valid, and reliable, to support applied use by practitioners.

Cluster analysis of symptoms among patients with upper extremity musculoskeletal disorders.

INTRODUCTION: Some musculoskeletal disorders of the upper extremity are not readily classified. The study objective was to determine if there were symptom patterns in self-identified repetitive strain injury (RSI) patients. METHODS: Members (n = 700) of the Dutch RSI Patients Association filled out a detailed symptom questionnaire. Factor analysis followed by cluster analysis grouped correlated symptoms. RESULTS: Eight clusters, based largely on symptom severity and quality were formulated. All but one cluster showed diffuse symptoms; the exception was characterized by bilateral symptoms of stiffness and aching pain in the shoulder/neck. CONCLUSIONS: Case definitions which localize upper extremity musculoskeletal disorders to a specific anatomical area may be incomplete. Future clustering studies should rely on both signs and symptoms. Data could be collected from health care providers prospectively to determine the possible prognostic value of the identified clusters with respect to natural history, chronicity, and return to work.

Patterns of memory: a normative taxonomy of the Wide Range Assessment of Memory and Learning-Second Edition (WRAML-2).

Memory is arguably the most important function of cognition. When left undetected, memory impairments are linked to life long underachievement and negative social consequences. Given that the construct of memory is multidimensional, the current study examined patterns of multiple indicators associated with memory across individuals ranging in age from 5 to 85 years who had been administered the Wide Range Assessment of Memory and Learning-Second Edition (WRAML-2). Multistage cluster analysis with independent age replications was used to empirically identify normative profiles in a sample of (n = 1172) typically developing individuals. This procedure considered how various indicators of memory operate in concert by accounting for the nonlinear multivariate relationships among them. Results supported nine common (or core) profile types that satisfied all formal heuristic and statistical criteria, including complete coverage, satisfactory within-type homogeneity, between-type dissimilarity, and replicability. A summary of the defining characteristics for each profile is provided.

A retrospective study of the factors associated with hypercoagulability in the pediatric patients at a tertiary care children's hospital.

OBJECTIVE: The objective of this study was to determine the risk factors of hypercoagulability in children. We explored the interaction of multiple risk factors with the incidence of thrombosis. Our hypothesis was that as the number of risk factors for thrombosis increased the actual incidence of thrombosis would also increase. DESIGN: Retrospective review from 2003 through 2006 based on a search using two electronic medical record databases. SETTING: Pediatric Tertiary Care Children's Hospital. PATIENTS: Two hundred twenty-six patients were identified and analyzed. MEASUREMENTS: Search terms included factor V Leiden polymerase chain reaction, prothrombin gene 20210A mutation, methylene tetrahydrofolate reductase mutation, antithrombin III, and protein C and S levels. Clinical data were compiled for regression analysis. MAIN RESULTS: The presence of one risk factor was not significant. Two risk factors increased the risk of thrombosis (p = 0.005; OR 3.128). Three or more risk factors further increased the risk of thrombosis (p = 0.003; OR 4.861). Older age (>11 yrs) was protective against thrombosis (p = 0.007; OR 0.995), and the presence of a central venous catheter when analyzed against accumulating risk factors showed a higher risk than that found during the regression analysis (p = 0.001; OR 3.638). CONCLUSIONS: The population at our institution is reflective of the previously reported standards for the genetic predispositions toward thrombosis. Although older age is associated with a lower incidence of thrombosis, the presence of a central venous access device is detrimental. Accumulation of factors results in an increased risk of thrombosis. This article suggests that when inserting a central venous access device, consideration of a hypercoagulation workup should occur. Those with any two or more risk factors, genetic or acquired, and the comorbidity of a CVL may warrant consideration for the institution of anticoagulation with an agent like low molecular weight heparin.

ADHD and method variance: a latent variable approach applied to a nationally representative sample of college freshmen.

This study employed a correlated trait-correlated method application of confirmatory factor analysis to disentangle trait and method variance from measures of attention-deficit/hyperactivity disorder obtained at the college level. The two trait factors were Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV ) Inattention and DSM-IV Hyperactivity-Impulsivity. The two source factors were self-reports and parent-reports. Data were collected for an epidemiological sample (N = 1,079) of college freshmen stratified for race/ethnicity, gender, and ability level according to national targets for the U.S. college population. Results revealed (a) parents' ratings were better measures of internalizing behavioral dimensions and that students' ratings were better measures of externalizing dimensions of behavior, (b) informants have a greater impact on behavior ratings than the behavioral construct that is presumed to be the primary cause of the behavior as measured by the CARE, (c) relationships among the method factors revealed a substantial amount of unique variance among informants, and (d) relationships among trait factors were largely within expectation.

Head and neck size and neck strength predict linear and rotational acceleration during purposeful soccer heading.

There is increasing societal concern about the long-term effects of repeated impacts from soccer heading, but there is little information about ways to reduce head impact severity. The purpose of this study was to identify factors that contribute to head acceleration during soccer heading. One-hundred soccer players completed 12 controlled soccer headers. Peak linear (PLA) and rotational (PRA) accelerations were measured using a triaxial accelerometer and gyroscope. Head acceleration contributing factors were grouped into 3 categories: size (head mass, neck girth), strength (sternocleidomastoid, upper trapezius) and technique [kinematics (trunk, head-to-trunk range-of-motion), sternocleidomastoid and upper trapezius activity]. Multiple regression analyses indicated size variables explained 22.1% of the variance in PLA and 23.3% of the variance in PRA; strength variables explained 13.3% of the variance in PLA and 17.2% of the variance in PRA; technique variables did not significantly predict PLA or PRA. These findings suggest that head and neck size and neck strength predict PLA and PRA. Anthropometric and neck strength measurements should be considered when determining an athlete's readiness to begin soccer heading.

ADHD and achievement: meta-analysis of the child, adolescent, and adult literatures and a concomitant study with college students.

This article presents results from two interrelated studies. The first study conducted a meta-analysis of the published literature since 1990 to determine the magnitude of achievement problems associated with attention-deficit/hyperactivity disorder (ADHD). Effect sizes were significantly different between participants with and without ADHD (sample weighted r = .32, sample weighted d = . 71; p = .001). Effects were also examined according to the moderators of age, gender, achievement domain (reading, math, spelling), measurement method (standardized tests vs. grades, parent/teacher ratings, etc.), sample type (clinical vs. nonclinical), and system used to identify ADHD (DSM-III-R vs. DSM-IV). Significant differences emerged from the moderator comparisons. The second study, using averaged effect sizes from the first study as a baseline for comparison, investigated achievement levels for an understudied age group with ADHD, namely, college students. Unlike previous studies at the college level, the sample incorporated both student and parent ratings (N = 380 dyads). The results were comparable to outcomes from the meta-analysis for college students and adults. Analyses demonstrated modest (R = .21) but meaningful predictive validity across 1 year to end-of-first-year grades. However, unlike earlier studies with children and adolescents, student ratings were as predictive as parent ratings. Findings are discussed in terms of the impact of moderator variables on ADHD and achievement.

A nationwide epidemiologic modeling study of LD: risk, protection, and unintended impact.

Through multiple logistic regression modeling, this article explores the relative importance of risk and protective factors associated with learning disabilities (LD). A representative national sample of 6- to 17-year-old students (N = 1,268) was drawn by random stratification and classified by the presence versus absence of LD in reading, spelling, and mathematics according to ability-achievement discrepancies or low achievement levels. The dichotomous classifications were regressed on sets of explanatory variables indicating potential biological, social-environmental, and cognitive factors, problem behavior, and classroom learning behavior. Modeling revealed patterns of high risk for male students and students evincing verbal and nonverbal ability problems and processing speed problems. It was shown that, absent controls for cognitive abilities (such as provided by the ability-achievement discrepancy definition), definitions keyed to low achievement will substantially overidentify ethnic minority and disadvantaged students and will be confounded by significantly higher proportions of students who display oppositional and aggressive behavior problems. Alternatively, good learning behaviors uniformly provide substantial reduction in the risk for LD.

Examining Neurocognitive Function in Previously Concussed Interscholastic Female Soccer Players.

Awareness of sport-related concussions in soccer has gained recent attention in the medical community. Interestingly, purposeful heading-a unique yet strategic and inherent part of soccer-involves repeated subconcussive blows to the head. We divided 210 female interscholastic soccer players into control (CON [never concussed]) and experimental (EXP [previously concussed]) groups. We assessed neurocognitive performance using the Automated Neuropsychological Assessment Metrics computer program before and after the players' competitive season. Headers were recorded at all sanctioned matches. Data were analyzed using a series of one-way analyses of covariance and t tests. Both groups essentially played in the same number of games (EXP = 16.1 vs. CON = 16.1) and had an equal number of total headers (EXP = 24.9 vs. CON = 24.3). Additionally, headers per game were surprisingly low in both groups (1.4 in EXP vs. 1.3 in CON). Unexpectedly, there were no significant differences between the EXP and CON groups across all dependent variables measured (p > .05). This study suggests that although previously concussed players involve themselves in purposeful heading (i.e., subconcussive insults) throughout a competitive season, there appear to be no negative consequences on neuropsychological test performance or concussion-related symptoms. Additional research is needed to determine what may result during the course of a playing career.

ADHD and college students: exploratory and confirmatory factor structures with student and parent data.

Exploratory factor analyses (EFAs) and confirmatory factor analyses (CFAs) were used to investigate the structure of the Student Report Inventory (SRI) and Parent Report Inventory (PRI) of the College Attention-Deficit/Hyperactivity Disorder (ADHD) Response Evaluation. The sample was composed of 1,080 college students and their parents and was stratified by ethnicity, gender, ability level, age, grade, region of residence, and psychoeducational classification status. Results varied according to the information source (self-report vs. parent). EFA uncovered and CFA confirmed 3 distinct and reliable dimensions for student reports: Inattention, Hyperactivity, and Impulsivity. By contrast, EFA and CFA uncovered a reliable 2-dimension structure for the parent-report data. Factor structures replicated across genders (3 factors for the SRI, and 2 factors for the PRI). Results are discussed in terms of the divergence of structures.

Factor and subtest discrepancies on the differential ability scales: examining prevalence and validity in predicting academic achievement.

Past literature has largely ignored the population frequency of multivariate factor and subtest score discrepancies. Another limitation has been that statistical models imperfectly model the clinical assessment process, whereby significant discrepancies between both factors and subtests are included in predictions about an individual's academic achievement. The present study examined these issues using a nationally representative sample (N = 1,185) completing the Differential Ability Scales. Results indicate that approximately 80% of children in a nonreferred sample show at least one statistically significant ability discrepancy. In addition, the global estimate of cognitive ability was the most parsimonious predictor of academic achievement, whereas information about ability discrepancies did not significantly improve prediction. Findings suggest that when predicting academic achievement, there is little value in interpreting cognitive scores beyond the global ability estimate.

Subgroups of Adult Basic Education Learners with Different Profiles of Reading Skills.

The purpose of this study was to identify subgroups of adult basic education (ABE) learners with different profiles of skills in the core reading components of decoding, word recognition, spelling, fluency, and comprehension. The analysis uses factor scores of those 5 reading components from on a prior investigation of the reliability and construct validity of measures of reading component skills (MacArthur, Konold, Glutting, & Alamprese, 2010). In that investigation, confirmatory factor analysis found that a model with those 5 factors fit the data best and fit equally well for native and non-native English speakers. The study included 486 students, 334 born or educated in the United States (native) and 152 not born nor educated in the US (non-native) but who spoke English well enough to participate in English reading classes. The cluster analysis found an 8-cluster solution with good internal cohesion, external isolation, and replicability across subsamples. Of the 8 subgroups, 4 had relatively flat profiles (range of mean scores across factors < 0.5 SD), 2 had higher comprehension than decoding, and 2 had higher decoding than comprehension. Profiles were consistent with expectations regarding demographic factors. Non-native speakers were overrepresented in subgroups with relatively higher decoding and underrepresented in subgroups with relatively higher comprehension. Adults with self-reported learning disabilities were overrepresented in the lowest performing subgroup. Older adults and men were overrepresented in subgroups with lower performance. The study adds to the limited research on the reading skills of ABE learners and, from the perspective of practice, supports the importance of assessing component skills to plan instruction.