hello i am new here so i hope someone can help me...to cut a long story short... i have damaged my knee i have a torn cartlidge and am waiting an operation... i need to exercise but cant get out and about really- yes i have two dogs but live in the country and am scared of taking them out- they are a bit lively! as one jerk of the chain and my leg would buckle- but am depressed about it,,...so need some kind of exercise- can anyone help?thanks....