I have bad knees. The cartilage is degraded minorly but this could become a major problem if I train on it. I have been resting for 2 months now and I hate every second of it. My life is miserable without parkour. I work on upper body and just recently got my Human Flag down and handstands on paralettes but I need something besides that. Does anyone have suggestions as to what is as exhilerating as Parkour but not involving jumping or running?