Corifeo... admit to not reading the articles. Don't have the patience for this stuff.
I am a trial and error person. I began walking on the treadmill at a max speed of 2.0 and hanging on for dear life. As I got stronger, I upped it. Now do 4.0 at a 2-4% incline. Correct form is necessary when doing any exercise.
Knees. Had the right one replaced 4/12. Weighed 230 at the time. Began at 246. Doc asked which knee I wanted done first. And will be the only one done. Dropped 75lbs over the last 2 years. For every lb. lost, there is a 4lb. pressure loss. I've lost 300lbs. of pressure on my left knee and it's doing well. And will do everything I can to avoid another surgery. So, if a person is able to lose weight in any way shape or form, it will benefit the knees, surrounding ligaments and other parts of your body. Also consider physical therapy exercises. Personally, my pt and the tens unit messed up my IT bands and surrounding muscles on both legs. Chiro straightened it all out with adjustments and recommendations on how to exercise to stretch, not contract the muscles. That's where the pain comes from a lot of the time.
Please, do not listen to everything that is written. Recumbent bike. Just being able to peddle slowly is exercise. Common sense always wins. Start slow, baby steps and work up from there.