Lie on your side with your knees bent and your feet roughly in line with your bottom.
Place your fingers at the base of your spine, about a centimetre out from the ridge of your spine.
Breathe in and out several times, focusing on expanding your lower ribcage.
Gently pull your pelvic floor and your lower stomach muscles up and back in towards your spine and try to tighten the muscles underneath your fingers.
If you are having difficulty, imagine you are going to arch your back under your fingers and you should feel the muscles start to contract.
Try to maintain the tension as you breathe in and out.
Hold this contraction, then relax.
As you get better, try to increase how long you hold the contraction for.
