Minimum width trapshooting pad / walkway

Is there a minimum width for a shooting pad?

 

I think all that is required is a place to put your feet while at least one contacts or straddles the center line of the post. It doesn't say you must stand on it, just contact it. We've shot on patio blocks , skids, concrete, blacktop with lines painted, and can't remember what else has been available just now. But we had fun!