Most times, injuries occur because some of the muscles involved in the execution of a trick are not strong enough to withstand the stress placed on the joints during movement. This often happens to children whose bones are still in the process of growing. The most common of these injuries are sprained or twisted ankles, which occur when the small but vital muscles that run down from the calf to the foot are not tough enough to cushion the joint underneath. To prevent sprained and twisted ankles, the muscles surrounding them should be trained and conditioned regularly.