Ergonomic stool
Ergonomic stools provide the combined benefit of being both good for your back and being a convenient spare due to the fact that you can fold them up when they are not in use. The stool is surprisingly easy to construct: there are no complicated joints to make and no special tools required. This stool is made out of 1 1/2" thick dowel, which can be difficult to find. However, if you cannot find this thickness you can get away with 1 1/4" wood.