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]
(..) Mr. Crouch? A man has died here, Fudge. And he won't be the last. You must take action. I will not. In times like these, the wizard world looks to its leaders for strength, Dumbledore! Then for once show them some! The Triwizard Tournament will not be canceled. I will not be seen as a coward! (..)2005 Harry Potter and the Goblet of Fire