Pretty much every client I have trained, and every person I have trained alongside, has had some kind of mobility issue to work out.
In other words, a problem with getting full, strong, complete range of motion around a joint either due to some issue at that joint or upstream of that joint. Or, some issue with overall body movement because of that.
Because of this, I've taken a special interest in things like Magnificent Mobility, Inside/Out, and this website:
As far as I can recall, my first introduction to Kelly Starrett was thanks to Joe DeFranco. I started reading what he wrote and watching his mobility videos and I haven't looked back.
The daily mobility drills are good stuff. And although a lot of the videos have a high conversation:instruction ratio, they are all useful if you have the problem being addressed.
I especially love the tagline and motto Kelly Starrett uses:
"All human beings should be able to perform basic maintenance on themselves."
Yes. The way we live out our lives is full of movement patterns our bodies respond poorly to. Knowing how to fix that, and being willing to fix that, is critical. Kelly Starrett's website and Youtube channel both provide a wealth of useful information for trainers, trainees, and normal humans everywhere.
His first daily WOD - a squat hold video - is a great place to start.
On top of being extremely knowledgeable, Kelly Starrett is also well spoken and entertaining. You might find yourself watching a few videos at a clip, and jumping into the mobility drills he suggests. Don't resist this - fixing mobility issues are well worth the time spent on them. The stretch in Episode 2 is well worth looking at and trying out.