Don't move the middle: dynamic prone bridge with small plate (part 2 of 5)

Part2 of the 'don't move the middle' core strengthening series involves the dynamic prone bridge with a small plate.
Set in the classic prone hold elbow bridge with a small plate (500g) on your lower back.  Move upwards onto your arms (push-up bridge).  Complete a slow, controlled cross touch of one hand and the opposite leg.  Return to the the 4pt bridge, and repeat for the opposite arm and leg.  Return back down on to your elbows.
As for all exercises in this series, the goal is to move arms and legs with minimal displacement of the middle of your body - the plate is supposed to remain still on your lower back throughout.

video: dynamic prone bridge with small plate