Running a camp for catchers as I do this is a very common question I am asked. My own 2 sons have never liked them, never wore them. Of the 105 catchers that were at my 2 weeks of summer camp more then 40 were wearing them.
The question that has always bothered me was what amount of research was done in the development of the knee savers regarding catchers, prolonged squatting, and eventual knee damage.
To get that answer I spoke at lengh with the doctor that designed them,patented them in 1991, and sold the rights to Easton. Dr Farrago is a doctor in Maine. What I learned was that there was no specific study done relating to catchers or sports at all. All of the research that was done, and conclusions drawn, from work done with coal miners. You know, 6 ft tall miners in a 4ft high caves, lotsa squatting going on there for sure.
The application for catchers was a spinoff from that research, and when it was applied to catchers it was initially applied to older MLB catchers with existing bad knees.
Dr Farrago was very clear that no studies were ever done regarding the preventitive value of wearing them as a youth catcher, (ages 9-12).
He also made it very clear that they MUST be worn on the lower strap settings to avoid putting pressure on the back side of the knee joint.
I then asked him whether it is the mere act of repeated squatting that causes this damage, seeing that the knee is designed to bend that way. My illustration was why are their entire Asian cultures that spend more time in a catchers squat position as a daily routine and never have knee problems? Elderly people in these cultures are in that position for hours a day, they do not seem to need Knee Savers. Dr Farrago has thought about that situation himself and does not have a medical reason why they do not suffer from this "catcher specific" problem. He questioned whether it may have to do with the fact that from childhood these people sit that way, but he was not sure.
Below is a picture of 3 good looking catchers from overseas, they do not seem to have any knee problems.
So it is clear that many older adult catchers have been able to lenghten careers after knee injuries with Knee Savers, the rest is still up in the air for me.