Introduction: In soccer, the players’ positions have been associated with specific functional overload, which may cause sports injuries. Objective: To investigate the occurrence and characterize sport injuries according to soccer player position. Methods: 232 male soccer players (129 professionals and 103 amateurs) from different sport teams in Mato Grosso do Sul, Brazil, were distributed in groups according to their soccer player position. Besides anthropometric characteristics, sports injuries were registered by using a referred morbidity survey. The occurrence of injuries was analyzed by means of the Goodman Test. Logistic regression models were used to investigate the relationship between different risk factors and the occurrence/-recurrence of sports injuries. Results: Forwards showed higher occurrence rates of sport injuries than other soccer position groups. Joint injuries in lower limbs constituted the most frequent registered cases. Muscle injuries in the back region were the most registered sports injuries among midfielders, while muscle damages in lower limbs were the primary injuries registered for other line positions. In the etiologic context, contact was the main cause of sports injuries in all groups. Most athletes (195) reported recurrence of sports injuries. Conclusion: The occurrence of sports injuries was higher among forwards. Traumatic joint and muscle injuries were the most prevalent registers in all line positions.

Background: Soccer related injuries are often reported in studies, but epidemiological research on this theme is rare in Brazil, Furthermore, the conditions in which athletes have returned to sports practice, namely, either symptomatic or asymptomatic, have been neglected in research. Objectives: The aim of this study was to describe the epidemiological features of injuries among professional Brazilian soccer players in relation to location, type, mechanism, severity, recurrence, treatment and, lastly, symptoms in return to sport. Study design: Descriptive and cross-sectional, observational study. Study center: School of Physical Therapy of the University of Mato Grosso do Sul, Brazil. Methods: 116 male professional athletes of teams from a Brazilian state championship were interviewed and information about injuries was recorded using a retrospective reported morbidity questionnaire. Data were analyzed in mean AE SD for physical characteristics and sports practice history in absolute and relative frequencies (chi-square test with Bonferroni's correction) for characterization of soccer injuries in terms of type, location, severity, recurrence and symptoms in return to sport. Results: The numbers of injuries per athlete and per injured athlete were 0.92 and 1.43 respectively. The injuries of muscle-tendon unit and the joint types localized on lower limbs constituted the most important clinical occurrences with significant difference both in relation to other types (p < 0.05). Moderate and severe injuries were the most frequent occurrences. In relation to mechanisms for each type of injury, body contact was at least three times more responsible for injury cases. This type of mechanism was associated with a significantly greater impairment of joint structures. Concerning occurrence and recurrence of cases, the number of recurrent injuries of the muscle-tendon unit reached about 7.5% of the first-time injuries, while the number of joint recurrent injuries integrated almost 40% of the first-time cases. Significant differences between first-time injuries and recurrent injuries were found only for muscle-tendon and joint structures (p < 0.05), while significant differences among the type of injuries within each type of occurrence (first-time or recurrent injuries) were also found between muscle-tendon and joint injuries (p < 0.05). In relation to athletes with symptoms, in return to sport, 77.6% of them were treated for their injuries but more than half of them returned with symptoms still present when compared to those who returned without any symptoms. Among athletes who did not receive treatment, a lower percentage (58.3%) returned to the sport with symptoms still present. Significant associations between treatment and symptomatology were not found.

Cold-Water-Immersion (CWI) has been frequently used to accelerate muscle recovery and to improve performance after fatigue onset. In the present study, the aim was to investigate the effects of different CWI temperatures on neuromuscular activity on quadriceps after acute fatigue protocol. Thirty-six young athletes (16.9 ± 1.4 years-old; 72.1 ± 13.8 kg; 178.4 ± 7.2 cm) were divided into three groups: passive recovery group (PRG); CWI at 5 °C group (5G); and CWI at 10 °C group (10G). All participants performed a fatigue exercise protocol; afterwards, PRG performed a passive recovery (rest), while 5G and 10G were submitted to CWI by means of 5 °C and 10 °C temperatures during 10 min, respectively. Fatigue protocol was performed by knee extension at 40% of isometric peak force from maximal isometric voluntary contraction. Electromyography was used to evaluate neuromuscular performance. The passive recovery and CWI at 5 °C were associated with normalized isometric force and quadriceps activation amplitude from 15 until 120 min after exercise-induced fatigue (F = 7.169, p < 0.001). CWI at 5 °C and 10 °C showed higher muscle activation (F = 6.850, p < 0.001) and lower median frequency (MF) than passive recovery after 15 and 30 min of fatigue (F = 5.386, p < 0.001). For neuromuscular efficiency (NME) recovery, while PRG normalized NME values after 15 min, 5G and 10G exhibited these responses after 60 and 30 min (F = 4.330, p < 0.01), respectively. Passive recovery and CWI at 5 °C and 10 °C revealed similar effects in terms of recovery of muscle strength and NME, but ice interventions resulted in higher quadriceps activation recovery.

Creatine has been used to maximize resistance training effects on skeletal muscles, including muscle hypertrophy and fiber type changes. This study aimed to evaluate the impact of creatine supplementation on the myostatin pathway and myosin heavy chain (MyHC) isoforms in the slow- and fast-twitch muscles of resistance-trained rats. Twenty-eight male Wistar rats were divided into four groups: a sedentary control (Cc), sedentary creatine supplementation (Cr), resistance training (Tc), and resistance training combined with creatine supplementation (Tcr). Cc and Tc received standard commercial chow; Cr and Tcr received a 2% creatine-supplemented diet. Tc and Tcr performed a resistance training protocol on a ladder for 12 weeks. Morphology, MyHC isoforms, myostatin, follistatin, and ActRIIB protein expressions were analyzed in soleus and white gastrocnemius portion samples. The results were analyzed using two-way ANOVA and Tukey’s test. Tc and Tcr exhibited higher performance than their control counterparts. Resistance training increased the ratio between muscle and body weight, the cross-sectional area, as well as the interstitial collagen fraction. Resistance training alone increased MyHC IIx and follistatin while reducing myostatin (p < 0.001) and ActRIIB (p = 0.040) expressions in the gastrocnemius. Resistance training induced skeletal muscle hypertrophy and interstitial remodeling, which are more evident in the gastrocnemius muscle. The effects were not impacted by creatine supplementation.

Objetivo: O objetivo deste trabalho foi avaliar os efeitos da crioterapia por imersão (CI) sobre o desempenho sensório-motor de esportistas após protocolo para indução de fadiga muscular localizada. Método: O presente estudo teve caráter experimental e delineamento prospectivo e teve participação de 36 esportistas universitários que foram divididos em três grupos: grupo recuperação passiva (RP), grupo crioterapia por imersão a 5ºC (CI5º) e grupo crioterapia por imersão a 10ºC (CI10º). Todos os grupos foram submetidos a protocolo de fadiga de membro inferior dominante em cadeira extensora. Posteriormente, o RP foi mantido em repouso, enquanto os demais grupos foram submetidos à imersão em água gelada a 5ºC e 10ºC, respectivamente, durante 10 minutos. Para avaliação do desempenho sensório-motor, foi utilizado o teste de equilíbrio (YBT), que foi realizado antes e no decorrer de 120 minutos após indução de fadiga. Resultados: Embora os resultados absolutos não tenham mostrado diferenças significativas entre os grupos, em termos relativos (%), o CI5º mostrou menor desempenho sensório-motor do que RP, o que foi mais acentuado no membro não-dominante. Todos os grupos obtiveram maior desempenho no YBT após 120 minutos de recuperação, quando comparado aos primeiros momentos de análise. Conclusão: Em conclusão, pode-se afirmar que o protocolo de CI de 5ºC durante 10 minutos aplicado após indução de fadiga neuromuscular resultou em menor desempenho sensório-motor no YBT, em comparação com o método de RP.

Introdução: O futebol é a modalidade esportiva mais praticada no mundo com milhões de adeptos, incluindo-se crianças e adolescentes. Objetivo: Analisar a ocorrência de lesões esportivas (LEs) e sua relação com fatores associados às lesões em jovens jogadores de futebol. Método: A casuística foi constituída por 102 jogadores (de 12 a 18 anos de idade) procedentes de dois clubes de futebol. Foram registradas informações sobre treinamento e antropometria e os dados de LEs foram obtidos por meio de inquérito de morbidade referida. Considerando-se a taxa de LEs por participante (2,4 LEs/ indivíduo), foram estabelecidos dois grupos: Grupo 1 (G1, n=61), constituído por voluntários com histórico de até dois casos de LEs, e Grupo 2 (G2, n=41), com participantes com pelo menos três casos de LEs. Resultados: Foram registrados 245 casos de LEs em 81 participantes (prevalência de 79,4%). Trauma foi a principal causa de lesões musculoesqueléticas (56,8%); 74,7% envolveram membros inferiores. Composição corporal e exposição foram diretamente associadas à recorrência de LEs. O G2 mostrou maior massa corporal (G1, 56,7±9,5; G2, 61,6±12,5kg) e maior histórico de prática esportiva (G1, 4,8±2,6; G2, 6,2±2,7 anos) do que o G1. Conclusão: A maioria das LEs teve instalação em membros inferiores devido a trauma. Quanto maior o índice de massacorporal e a exposição a treinos, maior a chance de apresentar três ou mais lesões