Workouts

My friends mom has recently let me borrow her workout videos that she had used until she bought new ones. I have not yet used them, but am very excited to start. One is called the "Crunchless Ab System" and my memory is not recalling the name of the other. I have always loved working out, but the two videos sound intense! With the combination of those I will be continuing my DDR workout sessions. DDR stands for Dance Dance Revolution for those of you who don't know the shorter name for the sweet game. It's never been about losing weight but toning my body, and I have had physical issues with exercising.
I was diagnosed 2 years ago with a rotated pelvic bone. When to much pressure, usually in a hard workout, I can easily throw my hip-flexor muscles into seizure like convulsions. When this occurs my muscles contract, unabling me to stand straight up and instead looking like a hunchback. I can not walk or move normally until about 3 chiropractor appointments later. It's been rough especially when you want to excerise but always have to be concious about doing it safely.
For all you bloggers out there, any other ideas on ways to exercise various muscles without using a treadmill or running? Input is appreciated :)