To protect your knees, get the appropriate soles. You don’t need to buy expensive, hard soled dance shoes.
Brian says, “The impact softening of contemporary trainers are excellent, BUT the soles are BAAAADDD. Stick some of these on your trainers / sneakers, and then dance away.”
(Click on image to be taken to Ebay Seller Page)
Also available with glue:
Women’s Soles on Amazon
Men’s on Amazon
Glue for the soles.