i think its best trained on the table wif an arm, if u both use side pressure and keep the wrists straight and locked and ur arm locked wif ur body slowly both apply pressure and try and keep it roughtly centre so if one starts to pin then they let off abit to keep it central,do this for 3 sets of hard pulls and make them last bout 10 sec each pull both arms, i do this at the end of my table workout,its working well and am getting stronger wif no injurys,but i agree wif devon i cant imagine how much pressure rigging up a big weight stack would put on the elbow tendons,like he said it will slowly get stronger,