I first saw this kind of thing at a machine shop my Pop took me to in about 1958. I do think the most important tool in the shop, after eye protection, is back protection fatigue being the father of injury and error. Rubber mats, no matter how dense, thick, or fluffy, laid over concrete still leave you on concrete, and they put you at the mercy of the manufacturer. As you can see in the pic, I do not stand on concrete. I have shared these with others who work on concrete (a punishment to mankind), and to a man or woman they all are amazed at how they immediately can feel the beneficial difference on their back and their feet vs "anti-fatigue mats." I made one for my daughter, who works in retail and overlaid the stringers with vinyl so as not to scratch the floor. I stand straight on the pallet or partially or one foot on and one foot off.
The treads are 3/16 oak, the pine stringers are planed to 1/2". I am 11/16" off the floor and never standing on concrete. It's 14" X 22" X 11/16". 1/4" crown staples 7/8" long leave a tail on the underside and are clinched for a durable tool. The finished product weighs about 1lb 10oz. I kick it effortlessly from machine to machine in my shop. The one in the background is about 30 years old and now has a few cracked or missing treads. I decided I needed a new one, which gave me the excuse to build several of them. I might offer them for sale to the public.
I agree it'd be better if my measurements were metric.
My apologies for the previous post without pics. I couldn't get the pics to go from my phone to the post. My thanks to BuffaloJohn.

