I'm rewriting some PPE standards for an underground mine. Typically workers wear 'muckers', or reinforced pull on rubber boots underground. The use of the boots extends to surface activities due to high rain / snowfall. To confound the issue, the mine is a lead mine and we require boot covers or removal of boots for entry into no operational areas (prevent contamination). Logically pull on boots would make this transition easier, however I cannot find any evidence that they provide adequate ankle support and stability - our site is remote, on the side of a hill and the underground work surface is frequently littered with 'ankle breakers' or small rocks. I can find research on comfort and ergonomics, but no evidence based recommendations for one over the other related to ankle stability or injury.