During the last years, artificial turf pitches have become commonly used for sports like hockey, tennis, rugby and football. The acceptance of this sport surface has found obj- tions in sports like football because first generations of artificial turf showed many problems and differences respect to the natural grass. These differences have been reduced but a serious problem exists yet: skin injuries due to sliding. This problem has been called "turf-burns". The risk of this turf burn curbs the players when playing on artificial turf (Lees and Nolan, 1998). Gaulrapp et al. found that the number of injuries on artificial turf was higher than on natural grass and these skin injuries frequently occur during a sliding trackle (Gaulrapp et al., 1999). These injuries are caused by two mechanisms: burn and scrape. It is possible that burn is due to an increase of temperature and it occurs when the player is sliding on the surfaces; it is possible that the scrape occurs when this slide starts because the friction is higher in this moment. This problem is being studied and some testing devices have been developed.