Similar to that, I've had clips that I wanted to play through their completion, then hold the last frame for five seconds. I load the clip twice in the timeline, and I tell the second clip to hold on the out frame. Then to change the clip's duration without changing the outframe, change the clip's speed. You can change the speed by a percentage or change the speed to match a particular duration. Set the duration to five seconds, and it's done.
For what you mentioned, you can just change the speed to a duration of one second. The same methodology can be used to hold any frame for any duration.
Not sure if this is the generally accepted way of doing things, but it's what I've managed to do. ----------------------------------------------------------------------------------
...but I'm just a C man trying to see the light