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]
(..) - Hey, do me a favour... - Luca never sleeps over with a broad. Well, Tom, you're consigliere. What do we do if the old man dies? If we lose the old man, we lose the political contacts and half our strength. The other New York families might support Sollozzo to avoid a long war. This is almost . (..)1972 The Godfather