improving conditioning & moderate rep bodyweight exercises/lifts goes a long way towards improving health.. short sprints, 200's, 400's, light running, jump rope, lateral movements, submax jumps from all plants, bodyweight stuff, avoiding risky exercises etc.. improving overall fitness.
To be frank, I'm kind of "afraid" of doing any "long distance" (>50m) sprints... I feel like my heart will blow up and die. I really think about that in my head. I've never had any resistance ever in my life... especially as I get drained of energy almost immediately because of nervous stuff (I get so "stressed" when I run that my energy just drains like rocket fuel).
so you can't jump/sprint anymore without pain? i figured the pain in the knee was still mostly isolated to squatting, considering your recent bound videos and depth broad jump videos.
I can sprint at high speeds without too much pain and I can jump maximally... it's just... weird. For the bounds, I only did them on the left leg, no right leg involvement. And yeah, I can do the depth jumps but there is pain.
if maximal jumping feels fine then it's definitely something else.. if you do slow runs, do them on grass etc, nice and soft, lots of blood flow, lots of very light impacts.
That's just boring... slow runs? WTF?

I can't just go to the track and see other people (Nightfly etc) train while I "slow run"... drives me nuts. I mean, I feel like my life is meaningless and shit like that. I know, crazy, but I still think that. Lost time...
Now I know, you're going to say "yes but it's for your healing"... haven't ever been injured in my life... that's a hard concept to comprehend.
if a dynamic warmup is really hurting the knee then man get that mri and get it figured out, thats if you have the right type of medical care.. if you don't, you'll have to do lots of light stuff to help rebuild/compensate to protect the knee.
A dynamic warmup isn't "really" hurting the knee but it does hurt it. When I do the knees to chest jumps unilaterally as part of the warmup, it still is an unilateral jump and land... so that bothers my knee.
But enough about me, hopefully I can rebound like Enzo here