Think of a treadmill as a tank tread, just kept off the ground. If the treadmill touches something in the back, it get's traction and will will try to "ride" th

Think of a treadmill as a tank tread, just kept off the ground. If the treadmill touches something in the back, it get's traction and will will try to "ride" that arm/hand/person/dog, pushing the treadmill backwards and even more onto the item stuck underneath. Most treadmills have a sort of bar/slat that prevents larger objects from being sucked too deeply under the treadmill. This means that while you can totally get your hand or arm stuck, the whole treadmill isn't going to be able to suck you under because you're going to get jammed up against that bar/slat eventually. You'd have to go under that bar (which is basically at floor level) to get into the same situation that happens 3 inches off the floor on a Peloton treadmill. Google treadmills and find a shot from behind the treadmill like you're walking up to use it. You'll be able to see the bar. Look at the Peloton treadmill and there isn't any bar. I can say that some cheap treadmills don't have this, but they lack the elevation and power a Peloton treadmill will have. Looking at the design, I can almost promise you they left it off for aesthetics, lots of treadmills are "boxy" because they provide a guard at floor level all the way around. Peloton's looks like an elevated tank tread, which is cool, but... no guards.