It's not easy, this inactivity, this couch-sitting, this watching people jogging outside my window. The trick is you have to be orderly. No dillydallying. You have to schedule your inactivity in order to make the best use of time. Intervals are the key. This is what works for me: (3 hours laying on the couch @ HR of 58) x 3 reps. In between reps, un-rest for 5 min by going to the bathroom, making tea, eating spinach, etc.
I think I have quadriceps tendinitis. People have informed me that the burning sensation I get above the knee cap while driving points to tendinitis. Thinking I had a patella tracking problem, I had been doing exercises to strengthen the quad, which is not what you want to do if you have tendinitis. Currently I am experimenting with intervals of RICE, foam roller, and light stretching.