I do plyometrics in training facility. The floor is concrete and I would like to suggest some kind of surface that better for the knees. It would only need to 4’ x 4’ or something. It there something like that out there?

Yep, some of the modern rubber type of mats work great. something like this:

Perfect. Thank you. Have you purchases from them?

I would call the 1-800 number at the top of the webpage. There is also a link to “request a quote” which will probably direct you properly.

It would also help to get better shoes with more cushioning, and replace them often. A lot of people fail to do that.