1. We can contract and stretch the optional muscles as we wish . On the other hand , we cannot contract the involuntary muscles as we wish. 2. We can move different limbs with the help of optional muscles. On the other hand, we cannot move any limb with the help of involuntary muscles. 3. This muscle helps our limbs to move by sticking to the bone. On the other hand , this muscle does not stick to the bone. 4. The epidermis , arms , legs, etc. are made up of these muscles.