With regards to force, it's easier to generate power when at least one part of you is touching the ground.
However, I still think precision is more important.
Also, I might be wrong, but it seems that DM's are caused by the joints being forced out of their natural position. Hence the "grippy DM's" where you grip the joint and dm it with next no no force, like in my replay
here (I'm on my school pc, so I can't upload it)