It kinda sounds normal to me. I think until they are in their late teens their joints still have gaps in them...if that makes sense! My pead told me that with our DS#2 when I asked if he needed a us on his hips as a diff pead had done one on our eldest. (we didn't get one done)

I know with my boys (3 yrs and 18 months) their wrists will 'click' if for instance they are sitting down and you pull them up.....know what i mean???? (hopeless sometimes trying to say in print what i mean! )

If in doubt though...see a GP or even a Chiro!

take care
xxxx