Hi, Cathe I was intrested in ordering your 8 new exercise videos but I had a question for you. I have bad knees are these videos mostly high impact or can they be modified? Right now I own your PS series. And recently just bought your wedding tape and mis. I just try to modify some of your movements. and maybe the tempo. Depends on my knees. Anyways I do do other workouts like kickboxing videos extc. I was just wondering if your new tapes would be worth me purchasing or is there just to much high impact in these videos that I would just have to modify the whole workout and it would not be worth it because I would not be getting as much of an effective workout? Please let me know what you think. Thank you very much.