"Also my miniature horse does a lot of rollbacks while in the round pen and I have some jumps set up for her also. Do you think this will hurt her joints if she does this daily??" i was not allowed to answer to your "round pen help" thread because of my age. If your mini has no diagnosed joint problems is see no reason why this would be unsafe. but, be sure not to over work her :) P.S. mind if i friend u?