Martin asks Mark to break his legs
Here's a description of the contestant's attempt. Someone's probably working on collecting some images to illustrate it.
Martin decides that the sounds of bones breaking would be the most horrible sound, so goes inside the playhouse with Mark and asks him to break his legs. Unfortunately, Lasse does not find his performance convincing, and is not bothered by the sounds it produces, so he earns third place.
(Written by Karl Craven)