Against the odds: exploring individuals' pushback mechanisms against commercialized football gambling.

Introduction: The need for money, the pursuit of pleasure, and the liberalized access to gambling have been documented in several pieces of literature as the drivers of gambling. Such drivers are predicated on commercialized gambling, leading to the growth of the gambling industry and constituting a structural influence that normalizes the activity among young people. Methods: Through a qualitative inquiry, this study investigates the social agentic factors of individuals who are susceptible to gambling. Fifteen non-gamblers were recruited across three commercial cities in Africa, namely Nairobi, Lagos, and Johannesburg. We first established the gambling susceptibility of the participants: their need for money, their passion for football, ownership of a smartphone, access to the internet, and exposure to football gambling marketing. Results: Consequently, we probed for their agency, which is indicative of why they do not gamble, despite being susceptible to engaging in the activity. Four major agentic factors were identified from the participants; knowledge of the industry's business model, conserving the integrity of football, identity of self, morality and/or religion model. Discussion: As such, these factors may be utilized to develop an intervention program for gamblers within the geographical context.

Prospective cohort study of long-term neurological outcomes in retired elite athletes: the Advanced BiomaRker, Advanced Imaging and Neurocognitive (BRAIN) Health Study protocol.

INTRODUCTION: Although limited, recent research suggests that contact sport participation might have an adverse long-term effect on brain health. Further work is required to determine whether this includes an increased risk of neurodegenerative disease and/or subsequent changes in cognition and behaviour. The Advanced BiomaRker, Advanced Imaging and Neurocognitive Health Study will prospectively examine the neurological, psychiatric, psychological and general health of retired elite-level rugby union and association football/soccer players. METHODS AND ANALYSIS: 400 retired athletes will be recruited (200 rugby union and 200 association football players, male and female). Athletes will undergo a detailed clinical assessment, advanced neuroimaging, blood testing for a range of brain health outcomes and neuropsychological assessment longitudinally. Follow-up assessments will be completed at 2 and 4 years after baseline visit. 60 healthy volunteers will be recruited and undergo an aligned assessment protocol including advanced neuroimaging, blood testing and neuropsychological assessment. We will describe the previous exposure to head injuries across the cohort and investigate relationships between biomarkers of brain injury and clinical outcomes including cognitive performance, clinical diagnoses and psychiatric symptom burden. ETHICS AND DISSEMINATION: Relevant ethical approvals have been granted by the Camberwell St Giles Research Ethics Committee (Ref: 17/LO/2066). The study findings will be disseminated through manuscripts in clinical/academic journals, presentations at professional conferences and through participant and stakeholder communications.

Essential elements of physical fitness analysis in male adolescent athletes using machine learning.

Physical fitness (PF) includes various factors that significantly impacts athletic performance. Analyzing PF is critical in developing customized training methods for athletes based on the sports in which they compete. Previous approaches to analyzing PF have relied on statistical or machine learning algorithms that focus on predicting athlete injury or performance. In this study, six machine learning algorithms were used to analyze the PF of 1,489 male adolescent athletes across five sports, including track & field, football, baseball, swimming, and badminton. Furthermore, the machine learning models were utilized to analyze the essential elements of PF using feature importance of XGBoost, and SHAP values. As a result, XGBoost represents the highest performance, with an average accuracy of 90.14, an area under the curve of 0.86, and F1-score of 0.87, demonstrating the similarity between the sports. Feature importance of XGBoost, and SHAP value provided a quantitative assessment of the relative importance of PF in sports by comparing two sports within each of the five sports. This analysis is expected to be useful in analyzing the essential PF elements of athletes in various sports and recommending personalized exercise methods accordingly.

Designing a study on footballers' injuries in the 2024 African cup of nations competition (Ivory Coast).

INTRODUCTION: To enhance players' performance and implement effective injury prevention protocols and surveillance programs in football, it is essential to conduct epidemiological studies. Since significant disparities in injury rates across various football competitions were reported, it is important to characterize injuries in the context of the African cup of nation (AFCON) competition. AIM: To determine the incidence and factors associated with injuries among African footballers during the 2024 AFCON competition, which will be held in Ivory Coast from January 13 to February 11, 2024. METHODS: Two expert physician in sports medicine will perform an analytical study (i.e.; a video-based analysis) of the 52 matches that will be played during the 2024 AFCON. The following parameters will be noted: i) Injury incidence, ii) Characteristics of injured players such as age, on-field position, and player league continent, iii) Characteristics ofinjuries such as mechanism, body location, moment of injury in terms of the minute of play and the round of the match, place of the injury in term of stadium zone, replacement consequent to the injury, absence next match, re-injury, recurrence of the injury with the same location during the competition, referee decision, and stoppage time for on-field injury, and iv) Characteristics of matches such as the match' schedule, ambient temperature, humidity, and wind speed. CONCLUSION: This study will allow enriching the existing literature with additional data regarding the injuries and the players' characteristics in the African context.

The role of Patient and public involvement (PPI) in pre-clinical spinal cord research: An interview study.

BACKGROUND: Patient and public involvement in research (PPI) has many benefits including increasing relevance and impact. While using PPI in clinical research is now an established practice, the involvement of patients and the public in pre-clinical research, which takes place in a laboratory setting, has been less frequently described and presents specific challenges. This study aimed to explore the perspectives of seriously injured rugby players' who live with a spinal cord injury on PPI in pre-clinical research. METHODS: Semi-structured interviews were conducted via telephone with 11 seriously injured rugby players living with spinal cord injury on the island of Ireland. A purposive sampling approach was used to identify participants. Selected individuals were invited to take part via gatekeeper in a charitable organisation that supports seriously injured rugby players. Interviews were transcribed verbatim and analysed thematically. FINDINGS: Six themes were identified during analysis: 'appreciating potential benefits of PPI despite limited knowledge', 'the informed perspectives of people living with spinal cord injury can improve pre-clinical research relevance', 'making pre-clinical research more accessible reduces the potential for misunderstandings to occur', 'barriers to involvement include disinterest, accessibility issues, and fear of losing hope if results are negative', 'personal contact and dialogue helps people feel valued in pre-clinical research, and 'PPI can facilitate effective dissemination of pre-clinical research as desired by people living with spinal cord injury.' CONCLUSION: People affected by spinal cord injury in this study desire further involvement in pre-clinical spinal cord injury research through dialogue and contact with researchers. Sharing experiences of spinal cord injury can form the basis of PPI for pre-clinical spinal cord injury research.

Concussion response and recovery in men and women's rugby union: A reflexive thematic analysis of player interviews.

Numerous concussion-management protocols have been developed in rugby, though little is known about player's personal experiences of concussion. Specifically, research typically refers to clinical recovery, with social and psychological sequelae post-concussion gaining little attention. This study aimed to explore the experiences of rugby players in relation to being concussed and recovering from concussion. UK-based rugby players (10 men, 9 women and 1 non-binary person) from school, university, club, military and semi-professional teams took part in semi-structured interviews (36 ± 12 minutes). Interviews were transcribed verbatim, and a reflexive thematic analysis was conducted. Players considered pitch-side healthcare a necessity, though amateur players highlighted the difficulty in consistently accessing this resource. In the absence of medical staff, players were reliant on the goodwill of volunteers, but their response to concussion did not always align with current concussion guidance. Players highlighted that concussion recovery could be socially isolating and that current return-to-play programmes did little to restore lost confidence, resulting in retirement from the game in some instances. Participants expressed a desire for more in-person concussion education and for greater coverage of holistic methods to support their recovery. This study highlights a need for further investigation of the post-concussion social and psychological changes that players may experience during their recovery. Greater focus on information relating to concussion recovery and return-to-contact in education programmes would likely benefit player welfare.

Level of Agreement Between Child and Parent Reporting on the Child Sport Concussion Assessment Tool (SCAT5).

CONTEXT: The Child Sport Concussion Assessment Tool, fifth edition (SCAT5), remains the consensus instrument for concussion evaluation in youth athletes. Both child and parent are recommended to complete the athlete background and symptom reporting. OBJECTIVE: To determine the level of agreement between child and parent medical history and symptom reporting and quantify their performance on the Child SCAT5 in male football athletes. DESIGN: Cross-sectional study. SETTING: National Collegiate Athletic Association Division I college football facility. PATIENTS OR OTHER PARTICIPANTS: A total of 157 youth male football athletes (age = 10.7 ± 1.3 years) participating in a university-sanctioned youth football camp and their parent or legal guardian. MAIN OUTCOME MEASURE(S): Youth athletes and their parent completed the athlete background (demographics, diagnosed medical history) and symptom evaluation (symptom items, total number of symptoms, and symptom severity score) of the Child SCAT5 and were instructed not to discuss reporting with each other during testing. Cronbach α tests were conducted to determine the internal consistency, and descriptive statistics determined the level of agreement between medical history, symptom reporting, and baseline performance. RESULTS: The internal consistency of the symptom items was high for both child (Cronbach α = 0.91) and parent (α = 0.92). Agreement on medical history ranged from 67% (learning disability or dyslexia) to 85% (attention-deficit/hyperactivity disorder), with 82% agreement on sustaining a previous concussion. Fourteen youth athletes reported having been hospitalized for a head injury, with zero matched parent confirmations. Individual symptom agreement ranged from 70.7% (gets distracted easily) to 94.9% (going to faint). Agreement was 35% on total number of symptoms and severity. Abnormal scoring ranged from 2% (going to faint) to 25% (headache) for child and 2% (double vision) to 28% (gets distracted easily) for parent reporting. CONCLUSIONS: Fair agreement was shown between children and their parent on medical history and self-reported symptoms on the Child SCAT5 at baseline. When available, child and parent reporting should be used for concussion assessment and clinical decision-making.

Role of the Menstrual Cycle on Performance and Injury Risk: A Survey of Female Professional Rugby Players in the United Kingdom.

BACKGROUND: Female athletic performance and injury risk is impacted by variations in the menstrual cycle (MC), but the understanding of the impacts and mechanisms influenced by the menstrual cycle on exercise performance are not fully delineated. AIMS AND OBJECTIVES: Evaluate associations between the menstrual cycle, perceived performance, and injury risk of elite female rugby players using an online survey. METHODS: An anonymous online questionnaire was completed by 150 elite female rugby players from two English rugby leagues, the Betfred Women's Super League (BWSL) and the Allianz Premier 15s (AP15s). The collected data were analysed thematically. RESULTS: The Chi-square test was used to assess associations between age groups and contraception usage, weight change, and training and playing performance; none of the associations were statistically significant (all p values > 0.05). Thematic analysis of 11,660 words of data revealed four themes: (a) MC impact on training and competition, (b) education and period management plans, (c) openness of conversations and comfort taking time off, and (d) injury risk. The impacted performance areas were physical (83.7%), psychological (85.7%), and nutritional (80.3%); players experienced decreased appetite, nausea, fatigue, strength declines, heighted emotions, and worsened focus. In total, 87.8% of athletes perceived the MC to negatively impact performance, 85.7% of players desired to be educated further to prevent injuries, improve nutrition, and training adaptions, 51.7% of participants perceived risk of injury to be higher during MC, and 86.4% of participants did not feel comfortable taking time off due to the MC, worrying that selection would be affected and about opinions from others. CONCLUSION: A clear negative impact on perceived performance and injury risk was reported by survey participants. The interaction of physical, psychological, and nutritional factors, and a lack of awareness and education emphasise the need for further comprehensive studies and interventions, with measures such as MC monitoring and profiling, education, and training adaptions to develop openness, knowledge, and understanding.

Are all hamstring injuries equal? A retrospective analysis of time to return to full training following BAMIC type 'c' and T-junction injuries in professional men's rugby union.

We aimed to determine whether the anatomical location (intramuscular tendon or T-Junction) of hamstring muscle injuries in professional men's rugby union associates with a prolonged time to return to full training and a higher rate of re-injury/subsequent injury. We reviewed the medical records of an Irish professional rugby union club to identify hamstring muscle injuries incurred across five seasons. Clinicians and players were not blinded to MRI results at the time of rehabilitation. A blinded musculoskeletal radiologist re-classified all included injuries (n = 91) according to the British Athletics Muscle Injury Classification framework. Players who sustained an injury with intramuscular tendon involvement required a longer time to return to full training compared to players who sustained an injury without intramuscular tendon involvement (78 days vs. 24 days). Players who sustained a biceps femoris injury with T-junction involvement did not require a longer time to return to full training compared to players who sustained a biceps femoris injury without T-junction involvement (29 days vs. 27 days). Injuries with either intramuscular tendon or T-junction involvement were not associated with an increased rate of re-injury/subsequent injury to the same limb (intramuscular tendon involvement - odds ratio = 0.96, T-junction involvement - odds ratio = 1.03). When a hamstring muscle injury involves the intramuscular tendon, the injured player and stakeholders should be made aware that a longer time to return to full training is likely required. T-junction involvement does not alter the expected clinical course of biceps femoris injuries.

The Surgical Management of NCAA Division 1 College Football Injuries Post COVID-19: A Single Institution Retrospective Review.

ABSTRACT: Cohen, JL, Cade, WH, Harrah, TC, Costello II, JP, and Kaplan, LD. The surgical management of NCAA Division 1 college football injuries post COVID-19: A single institution retrospective review. J Strength Cond Res 38(5): 906-911, 2024-The unprecedented COVID-19 pandemic had a significant impact on college football operations, including athletes' training regimens. As a result of these changes, concern for increased injury susceptibility post COVID-19 regulations has become a point of discussion. The current study sought to evaluate the incidence of surgical injury among NCAA Division 1 college football players at the authors' institution during the first full season after start of the COVID-19 pandemic compared with previous years. Retrospective chart review was performed for all players who sustained injuries requiring surgery while a member of the NCAA Division 1 football program during the 2009-2021 seasons. A p -value of ≤0.05 was used to determine significance. A total of 23 surgical injuries occurred in 22 players during the 2021 season compared with 121 in 118 players in the 12 previous seasons combined ( p = 0.0178; RR = 1.47). There was a significant increase in shoulder injuries ( n = 13 vs. n = 31; p = <0.0001; RR = 3.05) and specifically a significant increase in labral tears ( n = 10 vs. n = 30; p = 0.0003; RR = 2.74). No difference was seen in knee injuries ( n = 10 vs. n = 77; p = 0.27; RR = 1.35) and specifically no difference in anterior cruciate ligament injuries ( n = 3 vs. n = 31; p = 0.77; RR = 1.17). This phenomenon is multifactorial in nature, but alterations to players' training and preparations because of the COVID-19 pandemic likely resulted in suboptimal conditioning, leading to the increased incidence of surgical injuries emphasizing the importance of adequate strength training and conditioning.

Heterotopic Ossification and Platelet-Rich Plasma in Core Muscle Injuries: A Single-Institution Experience Over 6 Years.

BACKGROUND: A 2015 study of platelet-rich plasma (PRP) for groin injuries in National Football League (NFL) players alerted the authors to the possibility that PRP is associated with heterotopic ossification (HO). The current study of athletes seen between 2014 and 2019 provides a more comprehensive analysis of that observation. PURPOSE/HYPOTHESIS: This report describes the early results of groin surgery for athletes who had experienced failed PRP therapy performed by different practitioners and with an assortment of PRP techniques. The primary goal of this cohort study was to determine short-term clinical outcomes after surgery of PRP-treated patients. It was hypothesized that previous PRP treatment would be associated with the presence of HO among patients with core muscle injuries (CMIs). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All athletes seen at 1 institution and identified at their first visit as having received PRP for a CMI were followed and compared with patients with a CMI who had not previously received PRP. Although in many cases HO was observed on clinical examination or imaging, HO was identified intraoperatively in all surgical cases and confirmed pathologically. Successful surgery was defined as return to play at previously high levels of performance or greater as determined by the athletes' own assessments. All patients who had received PRP were followed for ≥2 years. RESULTS: Among 3642 patients with a new CMI seen between 2014 and 2019, 68 (1.9%) patients developed HO within the core muscles and/or adjacent soft tissues. Of the 68 patients, 60 (88.2%) were men, and the mean age was 34.5 years. Of the 68 patients, 62 (91.2%) were athletes and 44 (64.7%) had been treated previously with PRP. HO was observed in 24 (0.7%) patients without previous PRP treatment. Three athletes who received PRP retired early from sports because of HO and scar issues. In total, 22 of 28 (78.6%) NFL players who received PRP developed HO, compared with 0 (0%) of 28 randomly selected, age-, position-, and injury-matched NFL players. After surgical repair, 3-month success rates were 67.9% and 96.4%, respectively, in the PRP and non-PRP groups (P = .006). By 6 months postoperatively, PRP-treated patients were back to similarly high success rates compared with the non-PRP cohort. Scar tissue issues played a prominent role in the relative delay in definitive success. CONCLUSION: The present, more comprehensive study confirms the previous preliminary analysis that treating CMIs with PRP may be associated with HO.

Long-term effects of running exercises on natural grass, artificial turf, and synthetic surfaces on ground reaction force components in individuals with overpronated feet: A randomized controlled trial.

BACKGROUND: Overpronated feet are associated with alteration of lower limb mechanics. Also, quantifying ground reaction force-related changes due to exercise on different surfaces is important for understanding the potential risk of injuries. RESEARCH QUESTION: What are the long-term effects of running exercises on natural grass, artificial turf, and synthetic surfaces on ground reaction force components in individuals with overpronated feet? METHODS: Of 82 contacted individuals with overpronated feet aged 18-30, 22 were excluded because they did not meet inclusion criteria (20), and two declined to participate. Sixty individuals were included in randomization, the control (n = 15), hard court or synthetic surface (n = 15), natural grass (n = 15), and artificial turf (n = 15) groups. There was a sample loss of 8 individuals because of personal problems (2 in each group). The intervention groups performed running exercises on natural grass, artificial turf, and synthetic surfaces over eight weeks, three sessions per week. No training or test-related injuries were reported throughout the study. A force plate was embedded midway through the 18-running concrete path to collect ground reaction force data while running on stable ground before and after interventions. RESULTS: Findings demonstrated significant group-by-time interactions for vertical loading rate (p = 0.016, ETA=0.297). Post-hoc analyses showed increased loading rate amplitude in two natural grass and artificial turf groups (but not in the control and synthetic surface groups) post-intervention. SIGNIFICANCE: Running training on natural grass and artificial turf surfaces may place individuals with overpronated feet at a higher risk of injury while running on a stable surface.

Symptom presentation and evolution in the first 48 hours after injury are associated with return to play after concussion in elite Rugby Union.

BACKGROUND: Return to play (RTP) in elite rugby is managed using a 6-stage graduated RTP protocol, which can result in clearance to play within 1 week of injury. We aimed to explore how symptom, cognitive, and balance presentation and evolution during concussion screens 2 h (head injury assessment (HIA) 2) and 48 h (HIA3) after injury were associated with time to RTP) to identify whether a more conservative graduated RTP may be appropriate. METHODS: A retrospective cohort study was conducted in 380 concussed rugby players from elite men's rugby over 3 consecutive seasons. Players were classified as shorter or longer returns, depending on whether RTP occurred within 7 days (allowing them to be considered to play the match 1 week after injury) or longer than 8 days, respectively. Symptom, cognitive, and balance performance during screens was assessed relative to baseline (normal or abnormal) and to the preceding screen (improving or worsening). Associations between sub-test abnormalities and RTP time were explored using odds ratios (OR, longer vs. shorter). Median day absence was compared between players with abnormal or worsening results and those whose results were normal or improving. RESULTS: Abnormal symptom results during screens 2 h and 48 h after concussion were associated with longer return time (HIA2: OR = 2.21, 95% confidence interval (95%CI): 1.39-3.50; HIA3: OR = 3.30, 95%CI: 1.89-5.75). Worsening symptom number or severity from the time of injury to 2 h and 48 h post-injury was associated with longer return (HIA2: OR = 2.49, 95%CI: 1.36-4.58; HIA3: OR = 3.34, 95%CI: 1.10-10.15. Median days absence was greater in players with abnormal symptom results at both HIA2 and HIA3. Cognitive and balance performance were not associated with longer return and did not affect median days absence. CONCLUSION: Symptom presentation and evolution within 48 h of concussion were associated with longer RTP times. This may guide a more conservative approach to RTP, while still adhering to individualized concussion management principles.

Impact Deceleration Differences on Natural Grass Versus Synthetic Turf High School Football Fields.

American football has the highest rate of concussions in United States high school sports. Within American football, impact against the playing surface is the second-most common mechanism of injury. The objective of this study was to determine if there is a difference in impact deceleration between natural grass and synthetic turf high school football fields. A Century Body Opponent Bag (BOB) manikin was equipped with a Riddell football helmet and 3 accelerometers were placed on the forehead, apex of the head, and right ear. The manikin was dropped from a stationary position onto its front, back, and left side onto natural grass (n = 10) and synthetic turf (n = 9) outdoor football fields owned and maintained by public and private institutions on O'ahu, Hawai'i. Data was collected on 1,710 total drops. All accelerometers in forward and backward falls, and 1 accelerometer in side falls showed significantly greater impact deceleration on synthetic turf compared to the natural grass surfaces (P < .05). The results of this study provide evidence-based rationale to inform youth sports policies, particularly those aimed at injury prevention through safer playing environments and equipment.

Evaluation of the lower extremity functional test to predict lower limb injuries in professional male footballers.

The Lower Extremity Functional Test (LEFT) is a reliable and valid test for the measurement of athletic fitness, fatigue resistance, and speed performance. Contradictory results exist regarding the screening value of the LEFT in predicting lower limb injuries. The purpose of this study was to investigate the screening value of the LEFT in predicting lower limb injuries in professional male footballers. One hundred and twenty-one professional male football players participated in the study. LEFT was recorded pre-season and the lower-limb injuries were recorded during a 9-month season. Logistic regression analysis was used to determine the accuracy of the prognosis of LEFT. A total of twenty-five lower limb injuries were recorded. The model explained 53% of the variance in lower limb injury, showing that predictions by LEFT score is reliable, and correctly predicted 89.3% of cases, which is a large improvement. ROC analysis showed significant accuracy of the LEFT score (AUC 0.908, 95% CI 1.126-1.336, p = 0.001, OR = 1.227) in discriminating between injured and uninjured players. The optimum cut-off level of the LEFT score was 90.21 s; Our findings showed that the LEFT score was able to predict lower limb injuries in professional male footballers. The slower an athlete's LEFT scores, the more susceptible they are to future injury risk. Sports medicine specialists, football coaches and managers are suggested to use LEFT as a pre-season screening test to identify and prevent the weakness and functional imbalance of the athletes before the injury occurs by conducting this test.

Does playing surface affect the risk of anterior cruciate ligament injuries in the National Football League? A look at the 2017 - 2021 NFL seasons.

BACKGROUND: Anterior cruciate ligament (ACL) injuries are devastating injuries for athletes. Prior studies have shown increased ACL injury rates on non-natural surfaces versus natural grass in several sports. The purpose of this study is to calculate the prevalence of ACL injuries in the NFL on natural versus non-natural surfaces to determine if there is a significant increase on non-natural surfaces. METHODS: Accessing publicly available data for NFL seasons beginning with the 2017-2018 season through 2021-2022 seasons, all ACL injuries with publicly available data concerning timing and playing surface were recorded and categorized according to playing surface. Practice injuries or those without an identifiable playing surface were excluded. Incidence rates, defined as ACL ruptures per game, were calculated. ACL injuries were recorded for each playing surface, as well as the combined category of non-natural grass surface. Odds ratio was calculated to compare the risk of ACL rupture on non-natural surfaces vs natural grass. RESULTS: During the 2017-2021 NFL seasons, 173 ACL ruptures were identified with known surfaces. Injury rate for non-natural surfaces was 0.134 compared to 0.097 for grass. Injury rate ratio for non-natural vs natural grass surfaces was 1.211, a 21.1% increased risk of ACL injury in the NFL on non-natural surfaces vs natural grass. OR for non-natural surfaces 1.239 (95% CI 0.900-1.704). Based on these findings there is a trend toward increased risk of ACL injury on non natural grass surfaces, however this did not reach statistical significance. CONCLUSION: Numerous published studies show trends toward increasing rates of ACL injuries on non-natural playing surfaces vs natural grass. Based on our findings the difference is not statistically significant, however it does trend toward increased risk of ACL injury with non-natural surfaces. Further studies should be performed with larger sample sizes in order to further determine the risk of non-natural surfaces.

Models of Video Feedback for Youth Athletes Performing an American Football Tackle.

CONTEXT: Video feedback is an expeditious method for improving athlete safety when performing activities with an inherent risk of injury. Providing appropriate and validated feedback during tackling training in American football may be a mechanism for athletes to learn safe tackling performance. OBJECTIVE: To determine the effect of video feedback in the instruction of tackling form. DESIGN: Controlled laboratory study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 32 youth football athletes (28 boys, 4 girls; age = 11.8 ± 0.8 years) participated in 1 day of training. Of those, 14 participants completed 2 additional days of training and a 48-hour retention and transfer test. INTERVENTION(S): Video feedback using self as model, expert as model, combined self and expert model, and oral feedback to promote safe tackling performance in a laboratory environment. MAIN OUTCOME MEASURE(S): Shoulder extension, cervical extension, trunk angle, pelvis height, and step length by training block and over time. RESULTS: For the 1-day training group, main effects for time were observed for shoulder extension (P < .01), cervical extension (P = .01), pelvis height (P < .01), and step length (P < .01), with better performance for pelvis height and step length after combined feedback. For the 3-day training group, main effects of time were identified in pelvis height (P < .01) and step length (P < .01), with combined feedback showing better performance than other methods in shoulder extension and pelvis height. Combined feedback resulted in better performance compared with its component parts and oral feedback alone. In the combined model, participants viewed both their performance and the expert model, enabling them to see the difference between current and required performance. CONCLUSIONS: Combined feedback may be superior to other forms of feedback in improving movement performance. This effect can be generalized across disciplines that provide instruction and feedback in movement.

Blood-Brain Barrier Dysfunction and Exposure to Head Impacts in University Football Players.

OBJECTIVE: To investigate the link between dysfunction of the blood-brain barrier (BBB) and exposure to head impacts in concussed football athletes. DESIGN: This was a prospective, observational pilot study. SETTING: Canadian university football. PARTICIPANTS: The study population consisted of 60 university football players, aged 18 to 25. Athletes who sustained a clinically diagnosed concussion over the course of a single football season were invited to undergo an assessment of BBB leakage. INDEPENDENT VARIABLES: Head impacts detected using impact-sensing helmets were the measured variables. MAIN OUTCOME MEASURES: Clinical diagnosis of concussion and BBB leakage assessed using dynamic contrast-enhanced MRI (DCE-MRI) within 1 week of concussion were the outcome measures. RESULTS: Eight athletes were diagnosed with a concussion throughout the season. These athletes sustained a significantly higher number of head impacts than nonconcussed athletes. Athletes playing in the defensive back position were significantly more likely to sustain a concussion than remain concussion free. Five of the concussed athletes underwent an assessment of BBB leakage. Logistic regression analysis indicated that region-specific BBB leakage in these 5 athletes was best predicted by impacts sustained in all games and practices leading up to the concussion-as opposed to the last preconcussion impact or the impacts sustained during the game when concussion occurred. CONCLUSIONS: These preliminary findings raise the potential for the hypothesis that repeated exposure to head impacts may contribute to the development of BBB pathology. Further research is needed to validate this hypothesis and to test whether BBB pathology plays a role in the sequela of repeated head trauma.