The 'standing scale' strengthens your back muscles as well as your legs. In the starting position your arms are stretched upwards so that your elbows are at the height of your ears. Now place yourself on a leg and flex slightly your standing leg. Stretch the other leg backwards and lean forward with your torso, so that your arms and your stretched leg form a horizontal line. Remain in this position for 25-30 seconds and repeat the exercise with the other leg.