question about pup trailers

The answer given by cheeseman6697 is right on

 

my former employer called this a "chicken leg"....

you drop it down, it DOES NOT have to actually be completely flat on the ground however, the leg has several holes drilled into it, as well as the outer casing for it, then you use a pin and clip to secure it in place, to prevent it from collapsing....

its to prevent the fork lifts from tipping over the trailer, due to the location of the main landing gears. not all pups will have this however, as again my former employer had newer pups where the landing gear was much more forward than the older ones.