Irulan, that's the body position I think i try & do but don't do very well

The bit of trail you've shown us looks quite easy going down. Now imagine that same bit of trail without the ramp bit going over the log & that's mainly what we have down here...

I've been working on balancing on (on my knees) the swiss ball holding onto a pole (horizontally) in the hopes i'll get the exact core strength i need.

I'm off to play on a trail today