~ Lie flat on back and start by bringing knees up to 90 degrees.
~ Place finger tips above hip bones and establish engagement by drawing your core up through your centre and flattening your spine.
~ Slowly lower one leg down; be aware of any sudden movements on the non-moving side, and notice whether your spine stays flat to floor!
~ Repeat on the other side, looking for symmetry between right and left.
~ If your back remains flat / core stays engaged, progress to lowering both legs down with knees straight.
~ Be conscious of movement in your back, and look to see whether your stomach muscles stay flat or 'dome' up as your legs lower.
~ Any movement or doming indicates lack of strength!