Muscular lesions are among the most common injuries in sports medicine. How many times, maybe even at the most awkward moment of a tennis match or at the extra time of a soccer tournament, it occurred to you to feel a hard pain in the calf muscle and you tried to resist until to the end of the match, but without being able of moving normally? Or maybe that an opponent performed a studs-up tackle while you were kicking, obliging you to leave the field?