Infant bone cracking sound

Hello:
My baby boy is 6 month old and sometimes when he moves his legs I hear a little crack sound, just like a little bone cracking or popping. I'm not sure where it comes from but I've heard it in his legs and sometimes his ankles. It is similar to when you crack a knuckle or stretch your wrists or ankles. It is really worrying me and I don't know what to think. We have a Dr's appt in a couple of weeks, but I'm wondering if anyone else experienced something similar?
C.

[mami1323]

Yep, my son has that to.  He's been cracking since he was a month old or so.  It sounds like when you crack your knuckles.  I thought that I was hurting him but he's fine.  I don't think anything is wrong with.

[Me2mommy2b]

My DD's joints make that sound as well.  I was told by a physical therapist that joints do that when air fills them.  So when the joint is moved, it makes that popping/cracking sound.  I was told that it's not damaging to their joints and that it's normal in kids.

[Tanker Chic]

This is such a coincidence because my son has been having the same joint popping noise and I too was worried that i was causing it or hurting him.  He is only 4wks old and when I pick him up from under his arms sometimes I hear these faint popping noises and sometimes they happen when I just move him around.  I'm so glad to see we aren't the only ones experiencing this.  

[ikasky]

don't worry, it's normal to have popping sound from baby's joints. i've taken care of few babys and all of they have that.  

[leilaglim]

how bout sound of bone breaking when baby bends backward? it scared me. please help..

[rounak]

Thank God i was too worried for my 6 months old daughter as her bone use to produce the same cracking sound when we use to move her hand or leg during massage or while lifting her in our arms.Actually her S.Alk. Phosphate test showed at 225 DU/L. and high S. Alk Phos is normal in children with high growth rate but it can also mean problem in bone,liver,kidney etc also.but since her bone was producing cracking sound so I was worried about her bone.

[sirapp]

My 6 month had that happen too. Talked to a Chropractor and he said it was normal for bones to pop even in their back. If they grow fast their bones are trying to keep up with them. Just watch and make sure they are still wiggly from head to toe.