Evileeyore asked me a question by email about Accumulated Injuries and the Partial Injury rules on p. 136 of GURPS Martial Arts.
Can you use them together? Sure.
How would that work? It would make it easy to get to higher levels of injury. Instead of using the worst result, you'd effectively just be accumulated injury and moving up those thresholds until you reached crippling.
I haven't tried this - if I recall correctly, Sean Punch wrote those rules. I've never actually used them in play . . . although I have used a few of the other rules in that chapter in my games. Everyone loves double dismemberment!