Now that the quarterback has recovered from his injury, this week the team will be functioning 'at full strength' again. [=the team will have all its players again]
We are negotiating from a 'position of strength'. [=from a strong position; from a position that gives us an advantage]
He didn't mean to knock you down; he just 'doesn't know his own strength'. [=doesn't realize how strong he really is]
(..) It's the worst torture in the world. Waiting, when you know there's nothing you can do. Especially for people like us. But whatever strength, courage, madness, keeps us going, you find it, at times like these. You have it, soldier. It's what's kept you (..)2014 The Hunger Games: Mockingjay - Part 1