growing baby

In the past few days there have been a couple new developments:

1) Mateo’s first tooth arrived
2) He wants to eat my chin

Hmm…

What I love best about Mateo is also what I love best about you: his sweet good nature, his ready smile, and his endless curiousity and enthusiasm for all things new and adventuresome. Thank you for being such a wonderful pa-pa-pa-pa.

I’m in the midst of intensive grading, but I’m not to busy to share quickie versions of exciting Mateo news:

1) Mateo had his first solid food (banana) on Tuesday!
2) Mateo can go from lying down on his back to sitting all by himself (roll over to tummy, get on all fours, go to sitting)

So much more to say–especially on the eating front–but I’ve gotta go. Can’t wait til the quarter’s finally over!

This morning Mateo covered about two inches forward in ten minutes (no cheating by rolling over) with a one-legged crawl. Mateo’s belly is off the ground and one leg is bent with his knee on the floor. The other leg is straight and he pushes himself forward with the tip of that foot’s toes. It takes him a while to get into position and forward. He did this twice in a row and moved about two inches towards his goal. Poor guy was frustrated at his slow progress…

Mateo is now mobile, but only to his left. Mateo rolled about ten feet today in maybe 15 minutes or so. So no more leaving Mateo on the floor for quick potty breaks. It is pretty cool to watch him go: he rolls onto his tummy (wah), rolls onto his back (yay), rolls onto his tummy (wah), rolls onto his back (yay)…

Mateo’s been quite an outdoorsy boy the past week–he played in the kiddie pool with Roy last weekend and played on the beach with Nathaniel on Thursday. Fun fun!

There’s also been a bit of not-so-fun: last night Mateo woke up every 1.5-2 hours. For the week between my birthday and Mother’s day Mateo had slept 10+ hours straight each night (and usually an extra 1-2 hours more on top of that after an early morning feeding)–he must have been making up his sleep average last night. I think he might have been waking up for a couple of reasons: 1) he hadn’t pooed for 2 days, so maybe he was having tummy issues; 2) teething?; and 3) he’s finally remembered how to roll over from his back to his belly, but he doesn’t like to sleep on his belly and can’t roll back.

In other news, Mateo has learned to covet. He doesn’t just grab whatever’s available anymore and put it in his mouth. No, now there are particular things that Mateo just must have, such as: cell phones, the computer mouse, glasses…all the things that he really shouldn’t have. And now he’ll cry that he can’t have them and it’s harder to distract him with a substitute baby toy. Silly man.

Mateo also loves bouncing while we hold him. Up! Down! Up! Down! He can’t get enough of it. We’re going to get him a jumper tomorrow so he can have some independent bouncing time on his own. 🙂

As you may have seen in Linda’s recent post, Mateo can now sit. He can’t sit up yet, on his own, but he’s quite happy with sitting. Often he extends his arms to support himself, but sometimes he leans back and just balances.

The record so far was about 15 minutes of sitting and playing with something. These sessions usually end with a desire to straighten out (i.e. fall back — usually to be caught by a parent), or an overcompensation during balancing which terminates in a sideways tumble. Nonetheless, we’re thrilled!

For months, Mateo has been mastering static equilibrium in assisted standing. We would hold his arms and stand him up (which he would enjoy tremendously, and for a long while), and he’d stand. His legs would be usually straight — potentially locking his knees. Whenever some leg would buckle he would immediately try to straighten them out, and remain in the assisted standing position.

In the last few days, Mateo’s transitioned towards working on the much more complicated dynamic equilibrium problem. In this mode, his legs are usually bent and his butt is wiggly. We are obviously still holding him (or rather he’s holding on to our fingers), but his legs are constantly moving. As the knee bends or as he starts leaning towards one side or another, Mateo will adjust by moving the same leg a bit, or move his butt a little — all to remain standing, but not by locking his joints.

This is a welcome advance, of course. If I was a baby trying to stand up on my own, I would probably figure out next that by moving my feet around I can also affect my equilibrium — instead of keeping them firmly planted, I’d sort of shuffle around. Let’s see if this is what happens.

Dynamic equilibrium is in general much harder than static equilibrium. With static, you just compute the best position of your limbs to cause you to stand. If you miscalculate, you will probably fall. With dynamic equilibrium, you are basically always providing direction to your limbs: a push to the right, a wiggle in the back, a lean to the left, etc, where all of these gradually bring you closer to equilibrium. You may lean over far more than you intended, but that will just cause you compensate more. As long as you can use the wrong direction as input in the corrective command, you’re gaining net equilibrium.

For an example, see this video of a robot (“Big Dog“) maintaining equilibrium while walking on all fours — even as he is kicked, or as he slips.

This morning when Mateo woke up at 5:45 am, I fed him and put him back in the crib hoping he would sleep more. Well, seven minutes later he was fussing, so I came back to get him–and he’d rolled over! From his back to his tummy! Luckily we’d just started leaving both his arms unswaddled over the past few days, so he was able to do a mini pushup and wasn’t just stuck on his face. I wonder if this means he’ll be rolling over more…. Though he first rolled over (tummy-to-back) at 3 months, he’s only rolled over that way 5 times, and not at all in the past few weeks. We’ll see what happens with his new back-to-tummy roll!

I also think his swaddling days may be over soon. Since we’re no longer wrapping his arms, the swaddle isn’t quite so secure anymore. Last night when he woke up for feeding, only one leg was swaddled and the other was out and cold. Also, great news on the sleeping front–after a few bad nights, Mateo’s had three good nights in a row (waking up 1-2 times over 11-12 hours).

Anyway, Mateo’s bouncing around and smiling in his chair right now. Such a cutie!