hey, I was actually thinking of doing the exact same thing for my dissertation...but in the end decided to to a proprioception one instead
On my placements I've seen the physio's use pressure biofeedback cuffs (in the lumbar region when the patient is supine), to be honest I don't know a great deal about them, but the physio's I've met said they are really good at getting the patient to see the effects of thier TA contractions etc....
Best of luck!