Yo nabil, when I was 7 I broke my arm. More preciselly I separated the bones, the 2 large ones... (dunno how they call in English). Anyways, I had 3 operations and around 6 months of cast. here are some tricks. Do u know the big plastic bags for the trash? Well put in around your arm when showering. Sometimes, especially if the cast is bad-quality made, it will have little parts of it coming out. Like a sock I mean, dont pull it. Take a sharp blade and leave the cast always smooth. That way, it will be cleaner and more confortable. Well hope it helps. GOOD LUCK!