Try this exercise - the Compass
The aim of this exercise is to find the neutral position of the pelvis and spine whilst adding some movement to the lumbar spine.
Imagine that the your belly button is north, pubic bone south and east and west are the hips. Start by tiliting the pelvis north, you'll find that the spine is pushed to the mat and the tailbone has lifted. Now slowly tilt the pelvis south, you'll notice the lower spine has arched. Move between the north and south position slowly, using your breath, try not to overarch the spine when moving south.
Gradually come back to a level/neutral position where the tailbone is down on the floor and lengthens away and there is a small natural arch in the lower spine.
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