Sit towards the front of your chair and place a ball/rolled towel between your knees
While holding this ball in place, rock forward and press through your heels to come to a full standing position with your knees straight (with or without the use of your hands as advised by your physiotherapist)
After reaching your full standing position, slowly lower your self back to the chair to return to a seated position
Repeat this exercise as directed by your physiotherapist
Precautions
Ensure your perform this exercise on a stable chair
If this exercise aggravates your pain please stop and notify your physiotherapist