I have personal experience of this from two angles.
I had an encounter with some loose boulders in Glingling Hole in 1991, which left me with some severe ligament injuries in my knee. Incidentally this meant I had to do most of Gingling Hole on one leg, but that's another story. I was a bit wobbly about going caving again, so I walked (limped) up to Gaping Gill and went down on the winch. Going down the winch just did it for me, before I got to Birkbeck's ledge I was psychologically ready to go caving again.
THe other experieince I have is going caving with someone on their "comeback trip" after a serious injury. We went down Ireby Fell. It was a great trip, but on reflection a bit hard.
I guess both of these approaches were a little bit "kill or cure" and I reckon that's the best way. Don't get on a pony before you're ready, wait till you are ready and get straight back on a horse.
Mark