diifferential weight scale or 360 degree 'flat' scale with visual feedback.

Hello, I want to interface two weight scales. I could either purchase scales or build with FSR type sensor. Open to and appreciative of any ideas/suggestions.

Reason behind project: I have spinal chord injury and need to relearn how to sit with both feet having equal pressure on the floor. My idea is two pressure pads that I rest my feet on, and have display indicating when I am equal weight, and some indication of which foot is too light or too heavy. With this visual feedback I can train myself to sit. A bonus would be to have the scale useful at standing weight also, but that is in the future.

An old school analog version would be a rolling pin with a board on top that I tried to keep parallel to the floor. Perhaps I could fashion such and use strain gauge to feedback?

A more advanced approach would have a ball in lieu of a rolling pin to get 360 type feedback, but that might entail more than a starter project.

I have limited experience with Arduino, but plenty of programming/automation experience. I am looking forward to my first real project with it.

Thanks.

I prefer some kind of mechanical solution if possible. Since FSR is not accurate, and using two bathroom scales is not easy for a first project. I'm trying to visualize the problem, but I can't. If you sit down, the weight on the feets are equal. Or is it when your are going to sit down. Is the spinal injury in the lower back ? then it would be very important how you bend your back forward or backward. Do you have a good chair with lumbar support ? I hope that you have a water bed, to keep the spine flexible. Are you able to solder a few things for an Arduino project ?

What about a melody, every 15 minutes, to remind you to keep your spine upright.