Inevitably if you train long enough you'll run into a scenario where something is banged up.
A hurt shoulder, hurt knee, hurt back, hurt wrist...you name it. At some point one of those things will be hurting and could potentially derail training.
Some people might recommend just taking time completely off, but I think that's a terrible idea. If allowed, you should keep training.
In this video I share with you how to keep training and not lose any gains when it happens.