Apply rotation only to bone and not its children

Hi, I am manually controlling each bone of a skeleton model, I want to apply rotations only for a specific bone but not its children. As an example I want to apply rotations only to upper arm bone and not to fore arm bone linked. How do I do this?

You have to do it manually: something like

T = child.worldTransform;
parent.rotation = ...
child.worldTransform = T;

Well, the solution above might be not so good.
If you want to prevent bone rotation but otherwise obey the parent motion
you have to use Inverse quaternion.

Quaternion prot = parent_node.worldRotation;
Quaternion crot = child_node.worldRotation * prot.Inverse();
child_node.worldRotation = crot;

Something like that.