Noonan

when I was playing college golf my coach used to have me hit balls with a rubber hose around my back and bicepts. it wasnt the easiest drill to perform but it really helped my arms sync up with my body and made for a more consistant swing. I think that is the general principal behind this training aid so if you really want to try this go get $2 worth of rubber hose from home depot, tie it in a loop and swing with it around your torso.