I was bouldering with my frequent partner, and chose to get on a project of mine. Some other people asked if they could join us, and offered to provide a pad and a spot. Neither of us refused. I was about to make the final dynamic move, and missed the hold. When I landed I fell between the cracks of the mats due to poor placement (in an L shape rather than next to or on top of each other). This meant I twisted my knee.