I have noticed that big 5 has some puzzle mats on sale but the package says that they are for protecting your floor and you can put your equipment on them. My question is: Can they also be used to protect your joints? They are about 1/2 inch in thickness and they do have some give when I press on them. The salesgirl had no idea what they could be used for! Has anyone bought puzzlemats that are for floor protection and then used them for joint protection? Can they be used for both? Should I spend the money and get the greatmats one?