Stand behind a chair, hold onto a kitchen worktop or hold on to the back of a sofa for support.
Stand with your hip, knee and foot pointing straight forward. Keep your body straight.
With your whole leg straight, lift your operated leg out to the side as shown in the first image.

Hold for 2 seconds.
Slowly lower your leg with your foot back to the starting position.
Repeat 10 times.
Repeat this with your un-operated leg as shown in the second image.

To make the exercise a little more challenging, you can do this against an exercise band or with a 1kg weight around your ankle.