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Knees Pop During Squat/Leg Press

My knees sometimes pop when I’m doing squats and sometimes leg press. It doesn’t hurt and sounds like a knuckle crack; is this normal or am I doing something wrong?

My knee’s have always had a cracking sound like you describe since I was a kid - hasn’t done me any harm.

Then again, if your legs only do this with added weight, it may be something else.

The squat and most leg presses are not biomechanically correct so there is naturally some sheering force on the knee.

In the bottom position of the squat the knee is literally trying to pull itself apart. With this being said it does not mean you cannot perform both exercises safely and effectivly.

Try a little more warm up and see if that helps. If that doesn’t work pick some different exercises and come back in a few weeks to see if that has helped. If that doesn’t work I would take a good look at your diet. The cracking is normally just cartilage and although does not hurt any weird sounds the body makes it not a good sign. Its very tuff to spot eventual long term damage in its acute stages.

Best of luck,


I’ll second michael’s advice. My knees used to crack that same way. Since I’ve added in a few warm up sets for squats I havn’t heard the sound again.

I read this today, you might find it interesting:

Like on every rep? Mine will always crack with no pain on like my first warm up set but its just like having them crack from standing up when you sit too long nothing wrong and completely normal.

If there is no pain, I wouldn’t worry about it though if its a pop and it hurts your knees are probably traveling too inward.

Not on every rep, but sometimes, usually closer to the start of the workout.

OK so today was leg day. I just got home. I did a warm up of 16 reps with the bar, no pops.
Then, I did like 6 reps of 95lbs (Yeah, my weight sucks, but I’m progressing every week. Oh well.)

Then, I did my 4x14 with 105lbs and it was pretty pop-free except for two consecutive reps when my left knee (It’s always my left knee, I think. I only started paying attention today)popped. I stopped for a few seconds and continued with no pops.

I did that, unloaded the bar, and went over to load the leg press. I bent down and twisted slightly to grab a plate, keeping my feet planted but twisting my torso kind of, and my right knee sounded like it had midgets stomping on bubble wrap in there. I’ve never had that happen before, but it cracked like 5 times in a row really fast.
None of this hurts though.

I did 4x14 with 180lbs and my left knee popped on the first set a few times. Then, I did 8 reps with 240lbs and then 2x3 with 280lbs and nothing popped. I’d figure that it would pop with higher weight, but nope.

I’ve only been doing squats/leg press for a month maybe, so I don’t think I could have fucked up my knees too bad yet, but I really don’t want to start on the path to long term knee damage at 15.

They always pop in the below parallel position, too.

Your knees are definitely probably traveling inward which is a flexibility issue.

Your a newbie to the squat, watch these videos to help with flexibility and learning to squat properly. http://www.youtube.com/watch?v=Rq8CWv8UPAI

My sister had that same pop when first starting off but quickly fixed it happened the same way you describe also, when going below parallel and in only one knee-her right, which was drifted forward-

this poping sound is normaly caused by skins around your ligaments (i think its called “facies” in english, its “facien” in german ) and muscles which are sticking together when they weren’t used through their whole range of motion for some time.

Painless popping is nothing to worry about. Its like knuckles or anything else. One day at the Chiropractor I even asked my doc about this because my right knee does the same thing. He basically said don’t worry at all about it. Its just some air or gas escaping something like that.
Bottom Line: no big deal don’t worry. If there were any pain that would be completely different