I would look for the visual analogue pain scale or VAS. I believe it has good intra and inter therapist reliability and is what many of use learn as undergrads. Basically it is the old 0-10 (or is that 1-10) pain scale? I think there's even a modified version and one for children or for those of don't fully comprehend it by using versions of a smiling face from happy to upset...

More later, have to treat the first patient of the day