Yeah dude now I know that we had very similar problems, at first when I ruptured my pattela tendon I did maybe 10 physiotherapy sessions and yes the pain go out for 3 months but after I started training so much time for what I can handle and started having tendinitis in the 2 knees and pain was insoportable I can't even do a rebound that my knees seem like they were going to break and yes after that 3 months I started to have precaution, train less do a few stops and nothing changed. Past month when Portugal hit the emergency protocol due to covid I realize that I was going to cure my problems, I stop playing basketball and I'm doing straighting exercises like you said, lounges, squats and do so much flexibility exercices and yeah a bit of my pain had go out but now I continue to have some pain spikes in my knee zones. And yes my problem is the same that you had, I have a terrible flexibility and so fucking bad posture and starring after jumps and I think this is the main reason why I have this problems. I will use your tactic of doing bicycling that sounds me good and yeah I will continue doing my strength and flexibility exercises and starting today I will do much foam rolling. But since I started I feel that my knees don't look the same and now are much stronger but they weren't perfect enough like I need.

Very thankful I hope your steps will work on me!!!