Artificial turf is increasingly being used in the construction of football pitches. One of its characteristics is an infill of sand and rubber granules. At present, different materials and layer thicknesses, as well as grain sizes are used for the sand and mainly for the rubber, but they are chosen with little scientific evidence about their influence on the mechanical and biomechanical properties of the pitch. Based on knowledge from materials science, it is reasonable to suggest that grain morphology may have a large influence on pitch performance. This paper presents research conducted to assess the influence of different parameters related to infill grain morphology on the mechanical properties of artificial turf (force reduction (%), vertical deformation (mm) and vertical ball bounce (m)), as well as on their wear with use, measured according to the F ed eration Internationale de Football Association (FIFA) procedures. The results show a significant reduction of pitch performance with use and a significant influence of grain morphology in mechanical response of artificial turf with respect to impact forces and ball rebound.

The purpose of the present study was to identify the relationships among selected kinematic variables that affect the take-off phase and performance in elite jumpers. The jump distance was found to be related to: I) the athlete's approach speed before the instant of touch down; and ii) the exchange in spatial velocity components at take-off, which results in a gain in maximum vertical velocity of the centre of mass (CM), favoured by the use of an optimum touch-down angle of the take-off leg, an active landing of the foot at touch-down, and a motion of the take-off leg during the compression phase that helps to manage the loss of horizontal velocity. Nonetheless, the results show that an adequate velocity transformation requires an adaptive technical model to help jumpers to build an efficient individual technical pattern.

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Nowadays, the study of kinanthropometric parameters is an important tool for both early talent selection and for evaluating the efficacy of a training program. This study aimed to determine the anthropometric characteristics, body composition indicators and somatotype components of individual (athletics, swimming and triathlon), collective (handball and volleyball) and fight (karate and taekwondo) sportsmen and sportswomen from the Valencian Sports Technification Centre. This study involved a total of 62 men and 56 women, they were divided in three subgroups, including individual (athletics, swimming and triathlon), collective (handball and volleyball) and fight (karate and taekwondo) sports. The assessment was carried out according to the one established by the International Society for Advancement of Kinanthropometry (ISAK). For men, the highest value of femur breath, ectomorphy and medial calf and front thigh skinfolds are obtained for triathletes, athletics, volleyball and karate, respectively. The highest values of triceps, biceps and abdominal skinfolds, relaxed arm girth, endomorphy and body fat percentage are shown for taekwondo, while the other highest values are obtained with handball. For women, the highest value of ectomorphy is obtained for athletics. The identified kinanthropometric parameters are useful when comparing between sports and sports subgroups for the selection of subjects and to help in their performance assessment.

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