Hi Micheline - Sorry you had to go through knee replacement, but they do amazing stuff these days. My taiji’s teacher just had one (he is an expert skier and, in addition to injuries, also got the ‘bad cartilage gene’). He has made an amazing recovery in a very short time, due in a good part to his practice of taiji and qigong. In other words, his posture is good from practicing good alignment, and his quads are strong from lots of horse stance.
The main thing I would say for you is be diligent about working on your core strength through out the day! That pelvic stabilization will go a long way in keeping you lighter on your feet, which means you also will be lighter on your knees. I am guessing in addition to working your flexion back to where it was, your physio is giving you some core exercises. You can also follow the ones in the Chi Walking book or take a look at some of the videos on the chilivinginc channel on YouTube like this one - http://youtu.be/N8VXrv2KVeE Keepi.ng aligned will take the workload and stress off your new knee, as well as the other one, which may be working extra hard til the new knee catches up.
Remember the rule of Gradual Progress and meet your body where it’s at. Keep us posted and let us knwo how you are doing!
Certified Chi Running and Chi Walking Instructor