Prior to Week 9, Johnson was averaging only 3.2 yards per carry and had yet to produce either a 100-yard rushing game or a rushing touchdown.
He met both marks against the Rams, rushing for 150 yards on 23 carries, picking up two rushing touchdowns and rattling off his longest run of the season along the way.
So why was Johnson struggling for so long before breaking out against the Rams? Well, there are a few reasons he did so much better against the Rams than he did against everyone else the Titans have played up until this point.
First was that the Rams came in without respecting the run. Their defensive line and linebackers seemed to focus more on getting to the passer than on stopping the run. The 10 hits that the Rams put on Locker show that.
Third, the offensive line did a better job in run-blocking than they have been lately. Brian Schwenke continued to show why the Titans decided to play him over Rob Turner in his second start. He may have struggled with pass-blocking, but as far as the run is concerned, he's a big upgrade.
While all of those were important factors in Johnson getting a good game, the fourth reason is by far the biggest: The Titans used Johnson effectively.
Throughout the season, Johnson has been entirely ineffective between the tackles, but he's managed to still be a threat when he can get to the edge or in designed runs off the tackle.
In fact, Johnson's only two touchdowns before the Rams game came from very long runs (49 ad 66 yards) after a screen or dumpoff pass.
Still, the Titans kept pushing him up the middle, a task he's never been particularly well suited for, even when he was in his prime in 2009 and 2010. Johnson is a speed back, and speed backs don't do well in a power-running scheme.
Against the Rams, Johnson showed just how dangerous he can still be when he gets to the edge. It's just up to the Titans to keep putting him in situations where he can excel.
Going forward, that may be easier said than done.
One reason that the Titans were able to consistently send Johnson to the edge against the Rams, even when one of their tackles was backup Mike Otto, was because the Rams didn't really respect the run. Instead, they focused on attacking Locker.
Not every team will do that in the future. And after Chris Johnson had this bounce-back performance, even teams that would have slept on him a week ago will definitely be focusing on him now.
Of course, if a defense does sell out to seal the edge for Johnson, it makes it much harder for them to go all-out attacking Locker, which should open up the passing game, including dumpoff passes to Johnson.
Again, before this game, the only huge runs Johnson had made this season were from passes around the line of scrimmage that turned into runs. Just because it isn't technically a run doesn't mean it can't be a big part of your running game—just look at what the Saints have been doing with Darren Sproles for the last few years.
It's up to the Titans' coaching staff to make sure they maintain a balance in how they use Johnson. Get him to the edge when you can, but if you can't, try getting him screen passes in space instead of trying him up the middle over and over again, waiting for a big gain that's not going to come.
Johnson hasn't been effective up the middle for years, he hasn't been effective there at all this season, and chances are he won't be effective there going forward.
Johnson simply isn't a do-it-all running back anymore, but that doesn't mean he isn't still a dangerous weapon. What it does mean is that if the Titans want to get the most out of him, they'll need to continue using him correctly.
If they do, I'd expect Johnson to continue looking a lot better in the coming weeks.