Your physiotherapist may wish you to perform your exercises eccentrically. A muscle is worked eccentrically when it contracts and lengthens simultaneously.
To perform this exercise use the back of a chair or a table to maintain your balance.
Using your hands and both ankles, push up onto the balls of your feet, then transfer all your weight onto the side to be exercised, before slowly lowering your heel down to the floor.
Your physiotherapist will advise on progressions of this exercise – such as adding weights or performing it off a step.