Analysing the movement

I now had the upper body moving along with the empties, obviously it didn't look as accurate as it might have but it was beginning to look like the sequence that I'd recorded.

The head seemed to have a mind of its own; swinging around as it pleased, so I added a limit rotation in the x and z coordinates. 'World space' seemed to look up too high so I used 'local space.' This stopped the head spinning and it seemed to 'attach' to body better.

Next I had to consider whether to use an IK or track to constraint. The former seemed to more accurately place the mesh, so I replaced all the track to's with IK's. I was quite pleased with how the overall shape of the chracter was looking, but the arms seemed to cling to the sides so I experimented again with what constraints were needed.