Sit in your wheelchair with your feet resting on the floor, and ensure the brakes are applied.
If safe to do so, shuffle towards the front edge of your wheelchair.
Apply downward resistance to one knee using your hands.
When ready, push your toes into the floor as if trying to lift your heel against your own resistance.
Hold this position for the duration as instructed by your therapist.
Then return to your resting seating position.