Leg Extensions Bad For Knees?

I did a few searches and couldn’t find your (any of the coaches) views on the leg extension, in general, and if there is validity to all of the hate they get for being “bad for knees.”

One article states that it’s bad because it puts constant pressure on the ACL, but doesn’t any movement put pressure on ligaments and tendons?

If I remember correctly, the way I understood it being told to me (many years ago) was that the leg extension pulls your leg forward as you raise the weight, and that was the main issue for it being “bad”, but wouldn’t that issue be alleviated by letting the pad roll down the lower leg on the way up (and pointing your toes forward)?

I may just be understanding this incorrectly.

Some clarification would be much appreciated!

Some people find them uncomfortable.

But no, they aren’t “bad for the knees”.

Interesting. I had an ACL reconstruction from a big university sports clinic and the surgeons were adamant about not doing leg extensions because they destroy the knee(s). Is this perhaps a temporary warning, or is this a case of doctors who don’t even lift?

I think I can see someone doing leg extensions for better quad definition. But would adding them at the end of a squat session hurt your squat numbers? Could there be any productive stress on the quads for the squats?

There is some evidence suggesting that post-ACL patients may do better with closed-chain exercises compared to open-chain exercises like the leg extension.

But if they claimed that leg extensions “destroy” the knee, they’ll definitely need to provide some evidence for that.

Yeah he was adamant about it, warned me that it would just be terrible for my new knee, too much shear force, etc. I never touched them…but my donor graft reconstruction failed anyway. It’s been a drag because it seems to have caused super cartilage loss under my patella and constant knee pain now. Yay.