Permissions to modify a workitem at state/action level

Hi,

Is there is way to restrict the specific users to modify the workitem from one state to other state??

Example: We have "Ready for QA" and "Verified" states, We would like to have the QA team users only to modify the workitem state from Ready to QA --> Verified.

I don't see any default permissions to Modify a workitem at state/action level.

Whats the best way of doing in RTC World ???

Thanks,
Kiran