Potential financial loss and risk factors for hamstring muscle injuries in elite male Brazilian soccer players: a season-long prospective cohort pilot study.

Purpose: The aim of this pilot study was to analyze the potential financial loss and a range of potential risk factors for hamstring muscle injuries in elite Brazilian soccer. Methods: Thirty-four male players (age: 25 ± 6 years; stature: 180 ± 8 cm; body mass: 78 ± 9 kg; minutes played in matches: 2243 ± 1423 min) from an elite professional soccer club were monitored during a 12-month season. Muscle injury was identified by magnetic resonance imaging and the severity was defined according to the number of days away: minimal (1-3 days), mild (4-7 days), moderate (8-28 days), severe (>28 days). Potential financial loss due to the team's under achievements was determined. Dorsiflexion range of motion, eccentric knee flexor strength and isokinetic tests were performed during the pre-season. Association between dependent variables and the occurrence of injury was evaluated. Results: Nine hamstring muscle injuries with moderate severity were found in 8 athletes. Recovery time was 22 days off the field on average. Potential financial loss was $-43.2 million USD and earnings on merit money was 21%. Previous injury, increased flexor deficit 60°â€…/sec and increased flexor fatigue index 300°/sec were all associated with a greater chance of hamstring muscle injury. Ankle dorsiflexion range of motion was significantly lower in the injured group (35.6 ± 3° vs. 39.1 ± 4.9°; p = 0.017, effect size = -0.74). Conclusion: High financial burden was found in elite Brazilian soccer during one full season. Injured athletes had high hamstring fatigue index, knee flexor strength deficit, ankle range of motion restriction and previous hamstring muscle injury when compared to non-injured athletes. Therefore, preventive approaches in professional soccer players with previous hamstring injuries should be a priority.

Sagittal Balance in Professional Brazilian Football Players.

Introduction: Football soccer practice involves considerable risks of lesions, making it difficult to strike a balance between adequate preparation and the demand imposed on athletes. A high incidence of postural disorders among adolescents leads to questions about the influence of sports activity on the athletes' posture and sagittal balance. Methods: A cross-sectional study was conducted from panoramic spine radiographs of 110 professional Brazilian football (soccer) players. They were male and aged between 20 and 30 years. Measurements of pelvic incidence, pelvic tilt (PT), sacral slope, sagittal vertical axis (SVA), and lumbar lordosis were obtained by using the SurgimapⓇ software. Measurement values were compared with the Brazilian literature data. Lordosis type was categorized according to the classification of Roussouly et al., and the presence of spondylolysis and spondylolisthesis was analyzed. Results: Findings indicated that (1) among 110 radiographs analyzed, 104 had appropriate measurement quality; (2) values compared with the Brazilian mean demonstrated that PT and SVA were statistically lower in professional players (P=0.013 and P=0.037, respectively); (3) according to Roussouly et al. most participants presented Type 3 lordosis (54.8%), followed by Type 4 (26.9%); (4) eight athletes (7.7%) had spondylolysis, and among them, seven (6.7%) had spondylolisthesis. Conclusions: Significant differences in PT and SVA were found in professional athletes. The most common type of lordosis was the same as that found in the general population (Type 3), and the incidence of spondylolysis and spondylolisthesis was higher than that found in the general population, but lower than that found in football (soccer) players.

Evaluation of energy expenditure in forward and backward movements performed by soccer referees

The aim of this study was to measure the energy expenditure for locomotor activities usually performed by soccer referees during a match (walking, jogging, and running) under laboratory conditions, and to compare forward with backward movements. The sample was composed by 10 male soccer referees, age 29±7.8 years, body mass 77.5±6.2 kg, stature 1.78±0.07 m and professional experience of 7.33±4.92 years. Referees were evaluated on two separate occasions. On the first day, maximal oxygen uptake (VO2max) was determined by a maximal treadmill test, and on the second day, the oxygen consumption was determined in different speeds of forward and backward movements. The mean VO2max was 41.20±3.60 mL·kg-1·min-1 and the mean heart rate achieved in the last stage of the test was 190.5±7.9 bpm. When results of forward and backward movements were compared at 1.62 m/s (walking speed), we found significant differences in VO2, in metabolic equivalents, and in kcal. However, the same parameters in forward and backward movements at jogging velocities (2.46 m/s) were not significantly different, showing that these motor activities have similar intensity. Backward movements at velocities equivalent to walking and jogging are moderate-intensity activities, with energy expenditure less than 9 kcal. Energy expenditure was overestimated by at least 35% when calculated by mathematical equations. In summary, we observed that backward movements are not high-intensity activities as has been commonly reported, and when calculated using equations available in the literature, energy expenditure was overestimated compared to the values obtained by indirect calorimetry.

Perfil antropométrico de jugadoras chilenas de fútbol femenino / Anthropometric profile of female football - soccer Chilean players

Se evaluó un total de 43 jugadoras de fútbol, 26 seleccionadas chilenas sub 20 y 17 jugadoras del plantel campeón de fútbol universitario 2007 de la Pontificia Universidad Católica de Valparaíso (PUCV), todas ellas bajo su consentimiento informado. Se evaluó utilizando el protocolo de mareaje y medición de la International Society for the Avancement in Kineanthropometric (IS AK), en condiciones normales de temperatura, a primera hora de la mañana y después del vaciado urinario, por evaluadores con licencia nivel II de ISAK. Las variables medidas fueron peso, estatura de pie, estatura sentada, perímetros musculares, diámetros óseos y pliegues cutáneos. Todas estas medidas se utilizaron para las fórmulas de composición corporal de Kerr (1988) y para el método antropométrico del somatotipo de Heath-Carter (2004). Existe una diferencia de 3,4 años entre ambos grupos, lo que diferencia algunos otros componentes de la morfoestructura, como una mayor cantidad de grasa y menor cantidad de músculo del grupo sub 20 en comparación con el grupo PUCV y una representación gráfica del somatotipo que corrobora estas diferencias. Las diferencias en los componentes de la composición corporal entre ambos grupos tienen dos razones fundamentales. La primera por el mayor desarrollo y maduración física del grupo PUCV el cual al ser mayor, presenta promedios de estatura y peso también mayores. La segunda razón es el nivel de entrenabilidad del grupo PUCV que, al tener un mayor desarrollo, permite la realización de entrenamientos más prolongados y de mayor intensidad, demostrando un gran desarrollo muscular y menor cantidad de grasa en comparación con el grupo sub-20. Concluimos que según los factores antropométricos, el grupo PUCV es capaz obtener un rendimiento deportivo mayor que el grupo sub-20, siendo esto un importante fundamento al momento de elegir a las jugadoras pre-seleccionadas nacionales.

A whole of 43 was evaluated of football players, 26 selected Chilean sub 20 and 17 players of the champion nursery of university football of 2007 of the Pontificia Universidad Católica de Valparaíso (PUCV), all of them under his informed assent. Was evaluated under the protocol of marking and measurement of the International Society of Avancement in Kineanthropometric (IS AK) for the in normal conditions of temperature, in the early morning and after the urinary emptying, by assessors by license level II of IS AK. The measured variables were weight, stature of foot, stature sat, muscular perimeters, bony diameters and cutaneous folds. All these measures are in use for the formulae of corporal composition of D. Kerr, (1988) and for the antropometrics method of the Somatotype of Heath-Carter (2004). There exists a difference of 3,4 years between both groups what differentiates some other components of the morphoestructure as a major quantity of oily and minor quantity of muscle of the group sub-20 in comparison with the group PUCV and a graphical representation of the somatotype that corroborates these differences. The differences in the components of the corporal composition between both groups have two fundamental reasons. The first one for the major development and physical ripeness of the group PUCV who to the major being, has averages of stature and I weigh also major. The second reason is the level of performance of the group PUCV, which on having had n major development allows the accomplishment of trainings them prolonged and of major intensity, demonstrating a major muscular development and minor quantity of fat in comparison with group sub-20. We conclude that according to the factors anthropometrics the group PUCV is capable to obtain a sports major performance that the group sub-20, being this a foundation to the moment to choose the national pre-selections players.