As far as I can see from the research and summary the findings regarding the detrimental effects on the knees are an assumption. I coach sprinters predominately and gym is a major factor in our training. Maximum strength with as little weight gain is what we try to achieve. I am passed my used by date in regard to competitiveness (over 40 now), but I still like to lift and train with my athletes. A few years ago I had to stop lifting because the pain in my knees where too much, I was starting to drop just walking down the street, had pain going up stairs but worse going down. I had MRIs done on both knees and was surprised to find out very little wear in my meniscus (normal for my age) and all ligaments intact. The diagnosis was knee not tracking correctly and had to go into a stretching rehab program. After this the knees improved but only to a point. I could squat but knees would get sore for a few days and could not do any running. I then started to use knees wraps, I wrapped to push kneecap inwards on both knees. Initially after squatting, no pain or reduced pain. Within a few months squats started to improve and knees where getting better and better. Two years later have no pain squatting and no pain running. However if I try to squat heavy with no wraps the next few days my knees will be a little sore. I am back lifting above 200kg full squats at end of season without pain and knees never get sore. I have a couple of older athletes that where having sore knees during training and now I have them using knee wraps for their lifts. Every one of them now has little or no pain lifting and they do not have any knees problems running. From what I have seen knees wraps have fixed my athletes knees and this has allowed them return to full training and competition. I probably should go and get another MRI on my knees to see if there has been any significant degradation compared to a few years ago, however if I go by pain and mobility my knees are better than they were 10 years ago. The above is purely my observation with my athletes and myself, I am only going by pain reduction and improvement in mobility and performance.