Stand tall and stretch your spine. Are your feet level? Are your knees even? Are your hips level? Is anything out of alignment before you start to work it out?
If you lie down, do you feel level?
If you have knee pain and you do back stretches, does it get better?
If you have hip pain and you use your core and stabilise your body, does it improve?
Pilates works on many levels. To understand how Pilates reaches all the parts that other exercises cannot reach, you need to attend a small class with a responsible teacher. One to one or a Pilates workshop. As me for ore details if you are not sure what to do.
Pilates CAN help you. It is so much more than exercise.