Are leg extensions bad for your knees?
This question is not so popular compared to others but it certainly need to be addressed. A lot of people often times will perform exercises without really knowing the negative side effects of them. I hate leg extensions and think they should be avoided. They can cause some serious knee issues (especially if a heavy weight is used).
There are far better and safer exercises that you can do to increase size and strength in your quads. If you absolutely feel the need to do them, make sure you use very light weight and high reps.