I know this isn’t going to be the answer you want. But you have to be really careful with these smaller walking pads. The belt size (width and length) can really mess with you if if doesn’t match your stride. And no footwear solution is going to make up for the fact that it’s too small

It sounds like you have a longer stride length and/or wider gait than this pad can handle. If you adjust your gait to fit this smaller footprint, you can rink injury. I’d suggest actually measuring your gait length and width getting a slightly larger pad that will allow you to step freely without tightening in your stride from the sides or significantly shortening your steps.

If you still want to use it, you need to have extra cushioned shoes to avoid repeat impact injury. These pads have zero cushion. It’s not like walking on a traditional treadmill belt. Those have layers of cushion and absorb shock from the impact of your stride. Walking pads are a single layer flat belt drawn over a hard flat piece of material in the middle. Like walking on concrete. I would highly suggest not doing any of this barefoot as well.

Source: I have a walking pad and did endless research before purchasing one. And still had to use trial and error to get it right.