This particular type of side rolling (as demonstrated by @berndreicheneder ) always strikes an emotional chord with me. My father broke his back years ago being thrown off a horse (he was walking again very shortly after so it's all good). Hence, whenever I practice or teach this particular roll, I can't help but think of my father, in the middle of nowhere, in extreme pain and having next to no function in his legs. He managed to drag himself back to the homestead where my brother found him. The way he made it back was by rolling carefully onto his belly and dragging himself along the ground with his hands and forearms (we call it a prone crawl in MovNat). My dad used these techniques, not because they were "beneficial", he used them because he had no other choice.