Toddler Knee making Popping Noise?

[Toposlonoshlep]

My 21 month old's knee has been making a popping noise... It doesn't cause him any discomfort at all, but almost every time he bends it it goes "pop". His joints used to do that when he was a small baby, which I attributed to growing, but now what's up?

He did take a dive off the bed about a week ago, but other than a goose egg on his head didn't seem like he hurt himself...

My knees also pop every time I do a squat, so maybe it's genetic?

Is this normal?

[Courtney-Ostaff]

http://www.loc.gov/rr/scitech/mysteries/joint.html