Place a Swiss ball at mid-back height, against a wall behind you.

Place your feet at approximately shoulder width, knees paralell and pointing forward and lean back against the ball.

Lower yourself, by bending your knees to approximately a 90 degree angle and roll down the ball keeping your body weight travelling through your heels.

Once again, prior to commencing this movement gently contract your pelvic floor muscles and draw your belly button back towards your spinal column.

When squatting do not allow your knees to protrude out beyond your toes.