It's good to have options :). It sounds really hard but it's very basic and they demonstrate it really well and it's actually easy to learn with the right instructions.
I am not at all strong in my upper body (probably my problem! :() but already I am lifting 25kgs. Most of the ladies are a bit older than me (I am 50) and they are lifting heavier weights than me!
They actually have clinical classes for people with injuries or other health issues and the exercises are adjusted to their needs. Today there was a lady with a fused spine and lymphoedema in one arm. The exercise physiologist had adjusted the exercises to be safe for her. Obviously it is not possible to do this for the on-line program but the exercises on that are not using the weightlifting equipment. I think they are more resistance, balance and impact based.
Another alternative for people is to see an exercise physiologist in their area (if available) and have them design an appropriate program for them. Your GP should be able to refer you and with a GP Management Plan you are entitled to 5 visits subsidised by Medicare.
We are so lucky to live in Australia where we do have options, even in remote areas thanks to the Internet. Getting support on here is a great example of that. :)