Bum Knees?

I recently changed my leg routine and I am doing front squats and leg extentions. I find they both hit my knees in a bad way. Should I give them up and do something else?

If they are hurting you, definitely I would change exercises… try FULL squats. Without a bar, go down
“naturally” into what is close to a catcher’s position,
with your back arched, ribcage up against quads, hams
up against calves, feet angled a little out and shoulder
width apart, looking straight forward. This is your
bottom position for the squat. Start with light weights
and work up. DON’T give in to the temptation to not go
as low. Believe it or not, full squats can be very
therapeutic for the knees, while partial squats can
aggravate the knees.

Properform is also very important but, do you warm up & stretch before? I mean at least 15 minutes? I see it all the time,guys walking into the gym and climbing under the heavy iron-PROBLEM- these same individuals(over time) must drop exercises due to PAIN! My shoulder hurts-can’t bench press,knees hurt-can’t do front squats,etc.Spend time on yourself,do it the right way,and you will dramatically lower your injuries & enjoy this life-time passion we call bodybuilding-safely & pain-free.