Why does keeping active help bring on labour?

[RhiChiChi]

I tried 'keeping active' during pre-labour but it made my really tired by the time I went into labour. When I was in labour, the midwife kept telling me when I was sitting on the bed to try to sit up tall/straight to help with gravity. My labour was induced (ARM & Drip) so I was stuck on the bed being monitored which IMO was no help with the progression of my labour. I would have loved to be able to walk around, hop in the shower/bath etc....

[SweetPea]

I think if you're upright it helps gravity, I was painting doors when I was 40 weeks I had to squat on a small footstool because it was to hard to get up off the floor! I was 2 cm at 39 weeks and at 41 weeks went to be induced, had the gel and waters broke and contractions started so was never put on the drip and I dilated very quickly, much to the surprise of the midwife (especially for a first baby, I had the midwives telling me that with number two it will be quicker again). I'm not sure if it was just me or staying active that helped, but I'd give anything a go!