Roll and pitch done; awaiting yaw

One could think of Neil's mobility not just in terms of self-propulsion, which is still a long way off (I think), but also in terms of his ability to change orientation, which is starting to be more under his control. So I propose using the angles of rotation around x, y and z axes for this purpose. These are the roll, pitch and yaw angles respectively, and are defined relative to Neil as in the following pictures:

Neil as viewed by the most ordinary people

How engineers see him

Neil has already progressed well with pitch changes (lifting himself up with his arms when lying on his tummy), albeit through a fairly narrow angle. Still, it's not at all bad considering he's merely 13 weeks old.

An impressive pitch angle

Neil has now started with rolling, as he demonstrated to his doctor yesterday.

Start of roll

Half way done

Maybe this is the start of a yaw