All depends on the nature of your back injury. I'd suggest either the Canadian Back Institute or "National Spine Centre" - the NSC on 14th street NW in Calgary specialises in basket-case backs. They do surgery as a last resort, even though the place is owned and operated by surgeons. I'd suggest a good friend of mine who has been a physio at both of the above clinics, but he's on his way to a job in Victoria BC.
(of course, you don't say where in Alberta you live - Edmonton has a CBI, too)
My back has been a mess at various times since 1969. I've practiced judo from 1972-1980, competitive rowing from 1980 - 1983, and aikido from 1993 to the present. The physios I've seen have said that my back improved greatly after I started Aikido, BUT My back injury is not your partner's back injury, and you need to stretch, strengthen, and make sure your back is going to take even the warm-ups before getting thrown around... If your partner's discs have bulged, it may just be a matter of waiting, but CBI and NSC have both sent people back to work without surgery, but after a LONG period of rehabilitative exercise...
One piece of advice, though - Stuart McGill www.backfitpro.com