Carol, I would recommend the workout called MORE. It is for those who have physical problems. There is less twisting and it is easier to hold the form. Now, I am not a trainer, I am sure one will chime in here soon and give you some more advice.
You can also call the office and talk to them about your physical problems and they will also recommend the best workout for you and answer any questions you have.
I am 59 and stronger than I have ever been and more than ready for this next stage of life. I plan on keeping my muscle strength, bone strength and flexibility through t-tapp way into my 90's. Think of all the fun I am going to have the next 30 years!!