I had a streak of minor injuries in December that made training an educational experience. In terms of minor injuries, I think there are three types: (1) chronic, (2) acute from chaos, and (3) acute from specific technique…
The more you train the worse this injury gets. For me, both my shoulders are plagued by tendinitis. Basically, ice and rest makes these better, and training makes it worse. I think these tendinitis-type injuries are a part of life for most serious athletes.
How to prevent it (or minimize its effect): Chronic injuries cannot be managed in a half-assed way. They can often take as much dedication as the training itself. You have to ice it religiously when it acts up. Also, you have to do the types of exercises on it that your doctor usually gives you after you get surgery on it. So for my shoulders that means doing rotator cuff exercises with resistance bands every day. It doesn’t take more than 5 minutes, but it makes the world of difference in strengthening the tiny support muscles around the vulnerable area.
Acute injury from random chaotic scramble/accident:
A one-time random clash of some kind that could not have been easily prevented in a cosmic sense. This could be something you do, your training partner does, or those training around you do.
How to prevent it (or minimize its effect): Even though I say that it “could not have been easily prevented”, I think the chance of that kind of injury happening could be drastically reduced based on your general approach to training and the style of your game. I think that there are million factors involved here including your personality, your age, your physical build, the training approach in your gym, etc. For me, what works best I think is to err on the side of a Xande-style game vs a Jeff Glover style game. What I mean by that is I stick to a very basic game, and don’t get too creative positionally. All the creativity happens in the tiny details of the movements not the broad movement themselves. I use more pressure than speed, and try not to move explosively unless I have already extensively drilled that movement and know how to avoid injuring both myself and my training partner.
Acute injury from specific technique
A wrist-lock, a heel hook, a half guard lock down, a reverse de la riva sweep, etc. This is when a very specific kind of technique applied with power behind it causes a part of your body to turn or move in a way it’s not meant to.
How to prevent it (or minimize its effect): I try not to put myself in any position where I don’t have strength supporting my joints. Put another way, I avoid using flexibility to go to positions where my core, arms, or legs are not able to apply strength to get out of the position (when needed to prevent injury).