@jr2366 Beth, I am not an expert on anything and you can just google postural drainage and it will probably show you positions that you can lie in but I personally use postural drainage to clear my lungs and I don't have to use a vest or any device. It also has to do with people's physiology. Personally, I can just lie flat on my back, wait a minute or two and do a strong huff cough a couple of times or three short ones and clear my lungs. It takes a good 5 to 10 coughs for me personally. And then I go in "for the kill" afterwards with my saline solution and nebulize (because I truly believe that saline solution is key). Some do the opposite. Some do their saline first to break up the mucus and then clear their airways....I just happen to do it this way but it works great for me. Nan