That would be useful if i wanted the actor to be pushed in a specific way, but in my case i just want the actor to stay in place. It's kinda hard to explain, here's a terrible paint drawing :
http://i.minus.com/j45QoEbsYUtGA.png
Figure 1 :
Try to spawn an actor and use the console to kill him. He will simply crumble to the ground in a very specific way determined by the weight and other factors.
If you do that with multiple actors, you will notice they always fall the same way.
But you will also notice that they're ALWAYS fully falling, their bodies will always touch the ground no matter what.
Figure 2 :
By creating two invisible blocks i could prevent the body to fall backwards or forward ( again, determined by weight ) so the said ragdolled body will ( two possibilities )
1. Stay in place
2. Crumble in place
But in both case, there's a minimal chance that the body will fully touch the ground since it can't fall backwards or forward.
Like that i could obtain some interesting ragdoll-made-death-animations, like an actor falling on his knees and stay in that pose until the player decides to hit him.
It's very hard to explain, i hope you see where i'm going.