To grab one's ankles is essentially to bend over and prepare for what's coming. It is a reference to getting fucked in the ass (usually in a figurative sense). Sometimes the person grabbing their ankles is at fault, and sometimes it is the result of some new organizational policy.
The company just laid a bunch of people off and is requiring mandatory overtime for all salary-paid employees, so get ready to grab your ankles.
When our car broke down off the road in the middle of nowhere, I told John that we might as well bend over and grab are ankles because it was going to be a long time before help came.