Source: TimHe's Blog of SMS SCCM SCOM MOM and SCE
Tim Helton created a new OpsMgr utility that can be used to reset or recalculate all monitors for a single agent, or for all agents in your management group.
Command line tool that facilitates bulk reset of health monitors.
This can be very useful if you just had an event storm, and you want to reset everything back to "green". It also has the ability to identify "ManualReset" monitors, and reset or recalculate only them.
It displays most of the same data as healthexplorer, as well as some additional information.
Read more here.