Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 9.012
Filtrar
2.
Artigo em Inglês | MEDLINE | ID: mdl-32992687

RESUMO

Rules determine how team sport matches occur. Match-induced fatigue is specific to each sport, and may be associated with injury incidence. For example, the injury rate in soccer is distinctly higher during matches than in training sessions. Understanding the differences between team sports rules might be useful for enhancing rules (e.g., safer sport). Therefore, this study aimed to evaluate the impact of the rule-induced physical demands between soccer, futsal, basketball, and handball, focusing on substitution rules. Data from the elite team sports' rules (e.g., absolute and relative court dimensions; the number of players, substitutions allowed, total game time, time-outs) were collected, including the changes due to the coronavirus disease (COVID-19) pandemic in soccer substitutions, and comparisons were performed. The data showed that soccer has higher rule-induced physical demands: e.g., substantially lower substitution rate, higher dimensions in absolute (eight to fifteen times), and relative (four to eight times) values. Simulations also showed that soccer has extremely large differences, even considering COVID-19 substitution changes (from three to up to five). We conclude that elite soccer has remarkably higher overall rule-induced physical demands than elite futsal, basketball and handball, and increasing soccer substitutions permanently (e.g., unlimited) might mitigate overall soccer demands.


Assuntos
Atletas , Esforço Físico , Futebol/fisiologia , Esportes/fisiologia , Betacoronavirus , Infecções por Coronavirus , Humanos , Pandemias , Pneumonia Viral
3.
Medicine (Baltimore) ; 99(38): e22305, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32957391

RESUMO

RATIONALE: A developmental venous anomaly (DVA) is the most common intracranial congenital anomaly and is mostly asymptomatic. Thrombosis rarely develops in a DVA due to hypercoagulation. We report a case of ischemic stroke in the area of a DVA after minor head trauma in a patient with DVA and without a predisposition thrombosis. PATIENT CONCERNS: A healthy 17-year-old male was admitted to the emergency room due to left hemiparesis, which was caused by a ball hitting the right side of his head during a soccer game. DIAGNOSIS: Brain magnetic resonance (MR) susceptibility-weighted image showed several small veins draining to the central vein in the area from the right posterior putamen to the periventricular white matter. INTERVENTIONS: We diagnosed the patient with an ischemic stroke associated with a DVA and administered antiplatelet agents. The patient's autoantibodies (including antiphospholipid antibody) and factors of blood coagulation were normal. OUTCOMES: The left hemiparesis of the patient worsened by the second day of admission. Moreover, high signal intensity was observed in the DVA region of the diffusion weighted image of brain MR. The patient's symptoms gradually improved afterward, and left hemiparesis recovered fully 3 weeks after the onset. LESSONS: DVAs may predispose to ischemic stroke due to thrombosis and hypercoagulation, although it is rare. It is necessary to consider the possibility of ischemic stroke due to minor head trauma, even without factors causing hypercoagulation.


Assuntos
Concussão Encefálica/complicações , Acidente Vascular Cerebral/etiologia , Adolescente , Concussão Encefálica/diagnóstico por imagem , Ventrículos Cerebrais/diagnóstico por imagem , Ventrículos Cerebrais/patologia , Imagem de Difusão por Ressonância Magnética , Humanos , Angiografia por Ressonância Magnética , Masculino , Inibidores da Agregação de Plaquetas/uso terapêutico , Futebol/lesões , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico
4.
Braz Oral Res ; 34: e106, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32876122

RESUMO

The aim of this prospective epidemiological study was to evaluate the occurrence of incidents involving the craniofacial region of soccer players during three official FIFA competitions. The craniofacial incidents were identified by video analysis of all 144 matches of two FIFA World Cups (2014/2018) and the 2017 FIFA Confederations Cup. Data collection included incident type, incident severity, site affected, incident cause and referee decision. The multivariate Poisson regression model was performed to analyze the associations between covariates. A total of 238 incidents were observed in the craniofacial region (1.6 incidents/match), representing a rate of 48.5 incidents per 1000 hours. At least 80.6% of the matches presented at least one incident, and, in more than 60%, the referee's decision was no foul. According to severity, 26.8% of the incidents were classified as having mild or high severity. Incidents involving lacerations or fracture presented higher severity compared with hits (IRR 3.45[95%CI: 1.89-6.30]). Head-to-head impacts showed an incidence of severe incidents twice as high as those involving upper extremities (IRR 2.01[95%CI:1.07-3.76]). A high number of craniofacial incidents were observed in the last FIFA competitions. Head-to-head impacts and lacerations or fractures were associated with higher incident severity.


Assuntos
Traumatismos em Atletas , Futebol , Humanos , Incidência , Estudos Prospectivos
5.
Science ; 369(6505): 769-770, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32792381
6.
PLoS One ; 15(8): e0236959, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760122

RESUMO

The study aims were to describe positional differences in the acceleration and sprint profiles of professional football players in match-play, and analyse start speeds required based on the intensity of accelerations and decelerations. This longitudinal study was conducted over thirteen competitive microcycles in a professional football team from LaLiga 123. Data were collected through electronic performance tracking systems. Every player was categorised based on the playing position: central defender (CD), full-back (FB), forward (FW), midfielder (MF), and wide midfielder (WMF). In respect of acceleration profile, positional differences were found for all variables (p < 0.05), except average magnitude of accelerations (ACCAVG, p = 0.56) and decelerations (DECAVG, p = 0.76). The sprint profile also showed positional differences for all variables (p < 0.05), apart from sprint duration (p = 0.07). In addition, although low-intensity accelerations required significantly greater start speeds (Vo) than high-intensity accelerations in WMF (0.4 ± 0.2 km/h; p < 0.05) and FW (0.4 ± 0.2 km/h; p < 0.05), no significant differences (p > 0.05) were found in CD, FB, and MF. However, high-intensity decelerations were performed at significantly higher Vo than low-intensity decelerations in MF (2.65 ± 0.1 km/h; p < 0.05), FW (3.3 ± 0.1 km/h; p < 0.05), FB (3.9 ± 0.4 km/h; p < 0.05), WMF (4.3 ± 0.3 km/h; p < 0.05), and CD (4.1 ± 0.7 km/h; p < 0.05). Therefore, positional differences exist for most variables of the acceleration and sprint profiles. In addition, different Vo were observed between high-intensity and low-intensity accelerations as well as high-intensity and low-intensity decelerations.


Assuntos
Desempenho Atlético/fisiologia , Futebol/fisiologia , Aceleração , Adulto , Desaceleração , Humanos , Estudos Longitudinais , Masculino , Monitorização Ambulatorial , Corrida/fisiologia , Espanha , Dispositivos Eletrônicos Vestíveis , Adulto Jovem
7.
Science ; 369(6505): 866-870, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32792403

RESUMO

Can intergroup contact build social cohesion after war? I randomly assigned Iraqi Christians displaced by the Islamic State of Iraq and Syria (ISIS) to an all-Christian soccer team or to a team mixed with Muslims. The intervention improved behaviors toward Muslim peers: Christians with Muslim teammates were more likely to vote for a Muslim (not on their team) to receive a sportsmanship award, register for a mixed team next season, and train with Muslims 6 months after the intervention. The intervention did not substantially affect behaviors in other social contexts, such as patronizing a restaurant in Muslim-dominated Mosul or attending a mixed social event, nor did it yield consistent effects on intergroup attitudes. Although contact can build tolerant behaviors toward peers within an intervention, building broader social cohesion outside of it is more challenging.


Assuntos
Conflitos Armados/psicologia , Cristianismo/psicologia , Relações Interpessoais , Islamismo/psicologia , Futebol/psicologia , Humanos , Iraque
8.
PLoS One ; 15(8): e0235609, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32776940

RESUMO

Soccer is the most popular sport in the world and, since it is a contact sport, players are at risk for head injury, including concussion. Here, we proposed to investigate the association of heading and concussion with macroscopic brain structure among adult amateur soccer players. For this study, 375 amateur soccer players (median age 23 years) completed HeadCount-12m to estimate heading over the 12 months prior to MRI and lifetime concussion. T1-weighted 3D magnetization prepared rapid acquisition gradient echo (MP-RAGE) MRI was performed at 3 Tesla. Parcellation was performed using Freesurfer to extract regional gray and white matter volumes as well as regional cortical thickness and total intracranial volume. Regional cortical brain volumes were normalized by total intracranial volume. We categorized heading into quartiles and concussion as 0, 1 or 2 or more. Generalized linear regressions were used to test the association of heading or concussion with each brain morphometry metric, including age and sex, as covariates. Neither heading nor concussion were associated with reduced brain volume or cortical thickness. We observed that greater heading was associated with greater gray matter volume in the left inferior parietal area, which may reflect effects related to training.


Assuntos
Traumatismos em Atletas/diagnóstico por imagem , Concussão Encefálica/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Futebol , Adulto , Encéfalo/anatomia & histologia , Concussão Encefálica/etiologia , Córtex Cerebral/anatomia & histologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Tamanho do Órgão
9.
PLoS Med ; 17(8): e1003136, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760144

RESUMO

BACKGROUND: Recent evidence shows that sport settings can act as a powerful draw to engage men in weight loss. The primary objective of this pilot study was to test the feasibility of delivering and to evaluate preliminary efficacy of Aussie-FIT, a weight-loss program for men with overweight/obesity delivered in Australian Football League (AFL) settings, in preparation for a future definitive trial. METHODS AND FINDINGS: This 6-month pilot trial took place in Perth, Australia. Participants were overweight/obese (Body Mass Index [BMI] ≥ 28 kg/m2), middle-aged (35-65 years old) men. Participants were recruited in May 2018, and the intervention took place between June and December 2018. The intervention involved 12 weekly 90-min face-to-face sessions, incorporating physical activity, nutrition, and behaviour change information and practical activities delivered by coaches at 2 clubs. Data were collected at baseline and immediately postintervention. For trial feasibility purposes, 6-month follow-ups were completed. Outcomes were differences in weight loss (primary outcome) and recruitment and retention rates, self-reported measures (for example, psychological well-being), device-measured physical activity, waist size, and blood pressure at 3 months. Within 3 days of advertising at each club, 426 men registered interest; 306 (72%) were eligible. Men were selected on a first-come first-served basis (n = 130; M age = 45.8, SD = 8; M BMI = 34.48 kg/m2, SD = 4.87) and randomised by a blinded researcher. Trial retention was 86% and 63% at 3- and 6-month follow-ups (respectively). No adverse events were reported. At 3 months, mean difference in weight between groups, adjusted for baseline weight and group, was 3.3 kg (95% CI 1.9, 4.8) in favour of the intervention group (p < 0.001). The intervention group's moderate-to-vigorous physical activity (MVPA) was higher than the control group by 8.54 min/day (95% CI 1.37, 15.71, p = 0.02). MVPA among men attracted to Aussie-FIT was high at baseline (intervention arm 35.61 min/day, control arm 38.38 min/day), which may have limited the scope for improvement. CONCLUSIONS: Aussie-FIT was feasible to deliver; participants increased physical activity, decreased weight, and reported improvements in other outcomes. Issues with retention were a limitation of this trial. In a future, fully powered randomised controlled trial (RCT), retention could be improved by conducting assessments outside of holiday seasons. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12617000515392.


Assuntos
Estilo de Vida Saudável/fisiologia , Sobrepeso/terapia , Futebol/fisiologia , Perda de Peso/fisiologia , Programas de Redução de Peso/métodos , Adulto , Idoso , Exercício Físico/fisiologia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Obesidade/fisiopatologia , Obesidade/terapia , Sobrepeso/epidemiologia , Sobrepeso/fisiopatologia , Projetos Piloto , Fatores Sexuais , Método Simples-Cego , Austrália Ocidental/epidemiologia
10.
PLoS One ; 15(8): e0236669, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750092

RESUMO

This study examined the effect of a competitive season on salivary responses [cortisol (sC), testosterone (sT), Testosterone/Cortisol ratio (sT/C), Immunoglobulin A (sIgA), sIgA secretion rate (srIgA), alpha-amylase (sAA)] and upper respiratory symptoms (URS) occurrence in three teams of male soccer players (Under-15, Under-17 and Under-19 yrs.). Training and competition volumes, salivary biomarkers and URS were determined monthly. No differences were found for monthly training volume between teams. Incidence of URS was higher for the U15 (44.9% of the total cases). Higher sT and srIgA were observed for the U19, lower sC were found for the U17 and sAA showed higher values for the U15 throughout the season. In the U15, significant difference (p = .023) was found for sIgA concentration with higher concentration values in January compared to December (-42.7%; p = .008) and the sT showed seasonal variation (p < .001) with the highest value in January significantly different from October (-40.2%; p = .035), November (-38.5%; p = 0.022) and December (-51.6%; p = .008). The U19 presented an increase in sC in March compared to February (-66.1%, p = .018), sT/C were higher in February compared to March (-58.1%; p = .022) and sAA increased in March compared to September (-20.5%; p = .037). Negative correlations, controlled for age group, were found between URS occurrence and srIgA (r = -0.170, p = .001), sAA (r = -0.179, p = .001) and sT (r = -0.107, p = .047). Monitoring salivary biomarkers provides information on mucosal immunity with impact in URS occurrence. Coaches could manipulate training loads to attenuate the physical stressors imposed on athletes, especially at demanding and stressful periods.


Assuntos
Atletas , Imunidade nas Mucosas , Doenças Respiratórias/imunologia , Saliva/imunologia , Futebol , Adolescente , Biomarcadores/metabolismo , Humanos , Hidrocortisona/metabolismo , Imunoglobulina A Secretora/metabolismo , Masculino , Estações do Ano , Testosterona/metabolismo , alfa-Amilases/metabolismo
11.
PLoS One ; 15(8): e0236643, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841239

RESUMO

Accelerometry is a recent method used to quantify workload in team sports. A rapidly increasing number of studies supports the practical implementation of accelerometry monitoring to regulate and optimize training schemes. Therefore, the purposes of this study were: (1) to reflect the current state of knowledge about accelerometry as a method of workload monitoring in invasion team sports according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, and (2) to conclude recommendations for application and scientific investigations. The Web of Science, PubMed and Scopus databases were searched for relevant published studies according to the following keywords: "accelerometry" or "accelerometer" or "microtechnology" or "inertial devices", and "load" or "workload", and "sport". Of the 1383 studies initially identified, 118 were selected for a full review. The main results indicate that the most frequent findings were (i) devices' body location: scapulae; (b) devices brand: Catapult Sports; (iii) variables: PlayerLoadTM and its variations; (iv) sports: rugby, Australian football, soccer and basketball; (v) sex: male; (vi) competition level: professional and elite; and (vii) context: separate training or competition. A great number of variables and devices from various companies make the comparability between findings difficult; unification is required. Although the most common location is at scapulae because of its optimal signal reception for time-motion analysis, new methods for multi-location skills and locomotion assessment without losing tracking accuracy should be developed.


Assuntos
Acelerometria , Desempenho Atlético , Basquetebol , Futebol Americano , Futebol , Carga de Trabalho , Feminino , Sistemas de Informação Geográfica , Humanos , Masculino , Microtecnologia
13.
Educ. fis. deporte ; 39(2): https://revistas.udea.edu.co/index.php/educacionfisicaydeporte/article/view/338726, Julio 2020.
Artigo em Inglês | LILACS | ID: biblio-1104467

RESUMO

Objective: To determine the time-domain (SDNN, RMSSD) of heart rate variability (HRV) and heart rate (HR) of young football players in different training sessions. Method: 15 football players voluntarily participated (mean age = 15.5 ± 0.5 years, height= 171.1 ± 7.9 cm, weight= 62.4 ± 8.9 kg, BMI= 21.2 ± 1.9 kg/m2). They performed three different training: speed, coordination, and match formation. The HRV and HR of the participants were measured during warm-up, main training, and cool-down in each of the three different training sessions. Results: There was a significant interaction between time and intervention on RMSSD (Frmat= 2.983) and HR (Frmat t= 4.894). The results show that HR and HRV are affected differently by diverse training practices in football.


Objetivo: determinar el dominio del tiempo (SDNN, RMSSD) de la variabilidad de la frecuencia cardíaca (HRV) y la frecuencia cardíaca (HR) de los futbolistas jóvenes en diferentes entrenamientos. Método: participaron voluntariamente 15 jugadores de fútbol (media de edad = 15.5 ± 0.5 años, altura = 171.1 ± 7.9 cm, peso = 62.4 ± 8.9 kg, IMC = 21.2 ± 1.9 kg / m2), quienes se sometieron a 3 entrenamientos diferentes: velocidad, coordinación y partido de entrenamiento. La HRV y la HR de los deportistas se midieron durante el calentamiento, el entrenamiento principal y el enfriamiento en cada uno de los 3 entrenamientos. Resultados: hubo una interacción significativa entre el tiempo y la intervención en RMSSD (Frmat = 2.983) y HR (Frmat = 4.894). Los resultados indican que la HR y la HRV se ven afectadas de manera diferente por diversas prácticas de entrenamiento en fútbol.


Objetivo: determinar o controle do tempo (SDNN, RMSSD) da variabilidade da frequência cardíaca (HRV) e da frequência cardíaca (HR) dos futebolistas jovens em diferentes treinamentos. Método: participaram voluntariamente 15 jogadores de futebol (media de idade = 15.5 ± 0.5 anos, altura = 171.1 ± 7.9 cm, peso = 62.4 ± 8.9 kg, IMC = 21.2 ± 1.9 kg / m2), eles realizaram 3 treinamentos diferentes: velocidade, coordenação e partido de treinamento. A HRV e a HR dos esportistas se mediram durante o aquecimento, o treinamento principal e o esfriamento em cada um dos 3 treinamentos. Resultados: houve uma interação significativa entre o tempo e a intervenção em RMSSD (Frmat = 2.983) e HR (Frmat = 4.894). Os resultados indicam que a HR e a HRV são afetadas de maneiras diferentes por diversas práticas de treinamento em futebol.


Assuntos
Futebol , Sistema Cardiovascular , Exercício Físico/fisiologia , Frequência Cardíaca
14.
Nonlinear Dynamics Psychol Life Sci ; 24(3): 353-365, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32687778

RESUMO

This paper presents a case study which aims to establish a relationship between the homogeneity of passing distribution between players of a team and goal attempts in the team sport of association football. We observed data from 10 competitive football matches, involving 10 different professional football teams of different performance levels, competing in the Portuguese League during the 2010/2011 season. Performance data were analysed using the Match Analysis Software Amisco. Shannon's entropy measure was used to quantify the homogeneity of passing distribution within each team. Results suggested the existence of a pattern between an increase in the homogeneity of passing distributions and the attempts to scoring goals in the sample of competitive matches studied. A homogeneous distribution of passes can moderately predict (approximately 45% of accuracy) when a goal attempt will occur within the following minute of an entropy assessment.


Assuntos
Desempenho Atlético , Processos Grupais , Futebol , Entropia , Objetivos , Humanos , Masculino , Portugal , Estações do Ano , Software
15.
Int J Sports Physiol Perform ; 15(5): 696-704, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32698124

RESUMO

PURPOSE: To investigate within-player effect, between-player effect, and individual response of external training load from player tracking devices on session rating of perceived exertion training load (sRPE-TL) in elite football players. METHODS: The authors collected sRPE-TL from 18 outfield players in 21 training sessions. Total distance, high-speed running distance (>14.4 m/s), very high-speed running distance (>19.8 m/s), PlayerLoad™, PlayerLoad2D™, and high-intensity events (HIE > 1.5, HIE > 2.5, and HIE > 3.5 m/s) were extracted from the tracking devices. The authors modeled within-player and between-player effects of single external load variables on sRPE-TL, and multiple levels of variability, using a linear mixed model. The effect of 2 SDs of external load on sRPE-TL was evaluated with magnitude-based inferences. RESULTS: Total distance, PlayerLoad™, PlayerLoad2D™, and HIE > 1.5 had most likely substantial within-player effects on sRPE-TL (100%-106%, very large effect sizes). Moreover, the authors observed likely substantial between-player effects (12%-19%, small to moderate effect sizes) from the majority of the external load variables and likely to very likely substantial individual responses of PlayerLoad™, high-speed running distance, very high-speed running distance, and HIE > 1.5 (19%-30% coefficient of variation, moderate to large effect sizes). Finally, sRPE-TL showed large to very large between-session variability with all external load variables. CONCLUSIONS: External load variables with low intensity-thresholds had the strongest relationship with sRPE-TL. Furthermore, the between-player effect of external load and the individual response to external load advocate for monitoring sRPE-TL in addition to external load. Finally, the large between-session variability in sRPE-TL demonstrates that substantial amounts of sRPE-TL in training sessions are not explained by single external load variables.


Assuntos
Percepção/fisiologia , Condicionamento Físico Humano/métodos , Esforço Físico/fisiologia , Futebol/fisiologia , Adulto , Comportamento Competitivo/fisiologia , Monitores de Aptidão Física , Humanos , Masculino , Corrida/fisiologia
16.
J Sports Sci ; 38(11-12): 1432-1440, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32627682

RESUMO

We study the developmental and professional activities engaged in by 86 female adult soccer players from the senior national teams of Australia, Canada, England, Sweden, and the United States of America. Players completed the Participation History Questionnaire (PHQ) to elicit the amount and type of activities engaged in across their developmental and professional years, including milestones, soccer-specific activity and engagement in other sport activity. Greater specialisation than diversification characterised their childhood developmental activities, including all players starting in soccer in childhood and accumulating more hours in soccer activity than other sports during this period. However, interindividual variation further characterised these childhood activities, with a proportion of players diversifying into other sports and/or soccer play to a greater or lesser degree during childhood when compared to the other players. The amount of coach-led soccer practice increased for all players across their development culminating in an average of 15-16 h/wk across a 40-week season in early adulthood. In contrast, the amount of engagement in other sports and soccer peer-led play varied between players but generally decreased across adolescence to negligible amounts in late adolescence. Findings are commensurate with the deliberate practice framework and early engagement.


Assuntos
Aptidão , Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Destreza Motora/fisiologia , Futebol/fisiologia , Adulto , Austrália , Canadá , Inglaterra , Feminino , Humanos , Condicionamento Físico Humano , Especialização , Suécia , Estados Unidos
18.
Sports Health ; 12(5): 462-469, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32697672

RESUMO

BACKGROUND: The mechanisms of noncontact anterior cruciate ligament (ACL) injuries are an enormously debated topic in sports medicine; however, the late phases of injury have not yet been investigated. HYPOTHESIS: A well-defined posterior tibial translation can be visualized with its timing and patterns of knee flexion after ACL injury. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: A total of 137 videos of ACL injuries in professional male football (soccer) players were screened for a sudden posterior tibial reduction (PTR) in the late phase of noncontact ACL injury mechanism. The suitable videos were analyzed using Kinovea software for sport video analysis. The time of initial contact of the foot with the ground, the foot lift, the start of tibial reduction, and the end of tibial reduction were assessed. RESULTS: A total of 21 videos exhibited a clear posterior tibial reduction of 42 ± 11 ms, after an average of 229 ± 81 ms after initial contact. The tibial reduction occurred consistently within the first 50 to 60 ms after foot lift (55 ± 30 ms) and with the knee flexed between 45° and 90° (62%) or more than 90° (24%). CONCLUSION: A rapid posterior tibial reduction is consistently present in the late phases of noncontact ACL injuries in some male soccer players, with a consistent temporal relationship between foot lift from the ground and consistent degrees of knee flexion near or above 90°. CLINICAL RELEVANCE: This study provides insight into the late phases of ACL injury. The described mechanism, although purely theoretical, could be responsible for commonly observed intra-articular lesions.


Assuntos
Lesões do Ligamento Cruzado Anterior/fisiopatologia , Futebol/lesões , Tíbia/fisiopatologia , Fenômenos Biomecânicos , Humanos , Joelho/fisiopatologia , Masculino , Futebol/fisiologia , Gravação em Vídeo
19.
Artigo em Inglês | MEDLINE | ID: mdl-32646067

RESUMO

The aim of this paper is to analyze the relationships between a controlling interpersonal style, psychological need thwarting and burnout in adolescent soccer players and to test a structural equation model to analyze whether (a) a controlling interpersonal style is a predictor of psychological need thwarting and whether (b) psychological need thwarting is a predictor of burnout. A total of 103 male soccer players between the ages of 12 and 17 participated in the research (M = 14.91; SD = 5.56). The Controlling Coach Behaviors Scale, the Psychological Need Thwarting Scale, and the Athlete Burnout Questionnaire were used to evaluate the variables under study. The analyses revealed significant relationships between a controlling interpersonal style, psychological need thwarting and burnout. Furthermore, the proposed structural equations model, using the partial least squares (PLS) method, showed that a controlling style is a positive predictor of basic psychological need thwarting and that the latter is a predictor of burnout, as well as revealing an indirect relationship between a controlling style and burnout. This indirect effect of the controlling style variable on burnout can be enhanced (or attenuated) by the basic psychological need thwarting variable, which acts as a modulator.


Assuntos
Esgotamento Psicológico , Relações Interpessoais , Tutoria , Autonomia Pessoal , Satisfação Pessoal , Futebol , Adolescente , Criança , Humanos , Masculino , Inquéritos e Questionários
20.
Artigo em Inglês | MEDLINE | ID: mdl-32664643

RESUMO

The purpose of this study was to compare the effects of 6 weeks direct instruction and teaching games for understanding (TGfU) programs on the decision-making and execution (post-interventions), as well, as on the physical activity (PA) levels during sessions. Thirty under-12 football players participated in this study (age: 10.3 ± 0.45 years) and were randomly assigned to TGfU (n = 15) or direct instruction (n = 15) group. Two sessions/week were implemented. Results revealed that TGfU promoted higher levels (p = 0.043; d = 2.99) of light PA (28.96%) compared with direct instruction (27.55%). Non-significant higher sedentary PA levels (p = 0.073; d = 2.62) were found in the control group (35.48%). In terms of tactical principles, conservation of the ball increased the percentage of moderate to vigorous physical activity in TGfU (43.60%) compared with direct instruction (38.05%). According to the Game Performance Evaluation Tool (GPET), significant improvements (p = 0.018, d = 3.78) of the attacking player with the ball in the percentage of change between groups in the unsuccessful execution in TGfU (% = -62.2) were observed compared with direct instruction (% = 14.2). TGfU seems to be more appropriate than direct instruction to increase the light PA levels during sessions while no significant differences were found between programs in moderate and vigorous intensities. Regarding the effects of programs in decisions, greater improvements in decisions with the ball were found in TGFU compared to DI.


Assuntos
Exercício Físico , Futebol , Grupos Controle , Feminino , Humanos , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA