Easier said than done. Getting physical play and being clubbered (and taking it) during the play-offs and being injured is a far different matter.
A really bad lower back is major pain. Its like a dagger thrust into your lower back all the time. You cant jump. You cant move that much laterally. The back is part of the core, which is the foundation of the body. You cant do much being in the court if that back is stiff. I know it coz I have experienced it as Im a former athlete myself.
But I do agree that in some manner, West can will his young body through the pain and sucked it up. But again, sometimes, what the mind can lead, the body wont follow, especially if its injured.