Have not come across anything safe as regarding it Nikola. Ive been the route of I call the weight thing for Strength. I found it unsuccesfull as regards sporting motion, movement if you like. I think there are better ways to spend time on sports strength and conditioning. Funny talking to a guy, the conditioning guy today who is the Strength and conditioning man , for one of the major Football clubs in England. He told me they had got rid of all there weight machines, stopped using them because of the same reason. Things seem to be changing, there seems to have grown out of the 60s, where people selling the machines with the hard sell that their machines will make men Supermen by using their product a fact, but the bottom line was it was all Bollocks . Theres an old saying, train smart, Ive found you have not got to be smart to use Machines. Plus it wont make the Body smart.