How exactly do you tell if a PCB is common ground?


So I’ve been looking into the Deamgear fighting pads and recently but I don’t fully know if these count as common ground or not.

For a PCB to count as common ground should you be measuring 0 resistance across all ground points? Or is it a matter of just being able to get a measurement, showing that the points are connected, even if there are resistors in the circuit?

I tried searching with the forum search, google with “site:” and on slag coin but I didn’t find a simple answer.

Edit: Never Mind