This was a deliberate spoof video intended to go viral...

Some other posters claimed that the girl suffered brain hemorrhaging, later dying and the guy went to jail, later changing his name, this is pretty dubious...

Firstly here is the original clip where the premise is that a self help guru called "Franklin Apollo" aka "Todd Conner". This character you see here was created by a comedian named Dan Scahoff. The comedy mullet and the background to that clip alone ought to be enough for most people to know better. If you look closely you can see where the break line in the floor (about lines up with the leg of the ladder) due to there being a black high density mat recessed into the floor - these mats are similar in density to what is used in wrestling. They can be referred to as resin mats extreme sports athletes such as bmx or moto-x will learn tricks into a foam pit, then move on to a resin mat landing before performing their trick on the hardwood/skatelite surface that's less forgiving.

Now here is a "Todd Conner Promo video", note the actress at the 1 minute mark - this is the girl that some people have claimed is either dead or injured, the girl who was supposed to have been injured when the character was using the name "Franklin"- miraculously she seems to be alive and well and giving an endorsement of the motivational speaker character "Todd Conner".

Dan Sachoff's even mentions the video on his website: "Also on Dan's resume are his own web sensations, the viral video Todd Connor which he created and produced "

As for the claim of him going to jail... well you can see here on his IMDB, he seems to have had plenty of work in each subsequent years, no big gaps where he might have served a manslaughter sentence or similar.

So there you go, it is fake.