Pepe, perfect timing to answer your question -- here's the challenge preview clip with the dream teamers: http://www.cbspressexpress.com/cbs-entertainment/shows/survivor-philippines/video?watch=4dpc1ucy4b
It's called "Swing Ball" and it's pretty much what Tribe and others outlined above.
Each person takes 2 pots at a time. On the way there, you have to climb OVER the grid, so dexterity/balance are important....on the way back, you crawl under the grid. You take turns. When your team gets all 10 pots over to the end, then you all crawl together and 1 of the 3 has to swing the ball to smash the pots.
So the fact that I see someone behind Malcolm in the mud crawl doesn't necessarily mean they're ahead -- it could just be one of his tribemate behind him vs. another team.
It still doesn't seem fair that the other tribes don't have to use a woman....although now that I've seen the preview, I suppose strength isn't the main factor. A big guy could get hung up in the grid or doing the crawl through the mud, whereas a smaller woman might be quicker.