As I write, Soren is on his belly and not happy about it. However, he got himself there and now he's got to work it out.
It's interesting to me how he works on different stuff depending on his environment. When he's in his Vision Box, he looks at the lights and kicks. Now and again he'll go from side to side, but doesn't go his his belly.
When I'm writing "downstairs" (down the 2 stairs in our house), I put him on blankets where he can kick. That's what he was doing this morning. And when he's down here, he gets to his belly. The trouble is, once he's there, instead of pulling his arms and legs under his body to get in yoga Baby Pose, sprawls himself out flat with his legs and arms extended. You can't get anywhere from this position.
But Soren is strong enough that he can lift his head, upper body, and legs off the floor. So he arches his back, lifting his limbs, in a modified Yoga Bow pose. He moves his head side to side, but then he thumps it on the floor (ouch!). Then he gets more and more mad (who wouldn't?). The hard part is watching him suffer through this. However, as with any exercise, it makes you stronger even though it's not necessarily the most fun. If we don't keep him on his belly, he won't have the opportunity to figure out to pull his legs and arms back under to push himself up.
Of course, he also gets so mad, he gives up and falls asleep. Again, I don't blame him.