Baby seems stiff and tense

[lillypie]

I occasionally look after my friends 3 month old son and I've noticed that he always seems tensed up.
I mean when you hold him you can feel the tension in his little body and while he's sleeping if you move his arms around they will just stay where you put them almost like a little robot.
He's a happy little dot who smiles and laughs and likes to chat,but having had three very relaxed babies who were very floppy when sleeping I,m facinated by him.
Does anyone have a baby like this?

our ds2 was like this until he was adjusted by a chiropractor at 3 weeks old. Turns out he was jammed in his neck from a ventouse delivery . However he definitely wasn't a happy little dot when awake - he screamed the house down day and night for the first 3 weeks . He is happy as anything now though.