@Override
    protected void dynamicUpdate() {
        assert !getRigidBody().isKinematic();

        Transform transform = localBoneTransform(null);
        getBone().setLocalTransform(transform);

        for (Joint managedBone : managedBones) {
            managedBone.updateModelTransforms();
        }
    }
Update this link in Dynamic mode, setting the linked bone's transform
based on the transform of the rigid body.
jme3-jbullet/src/main/java/com/jme3/bullet/animation/BoneLink.java