Therapy for the Handicapped with OsteoPorosis?

I just met a woman with severe osteoporosis, who had polio in both her legs as a child. She has to use a power chair and fell out of it and broke her leg. She is on Fosamax/Alendronate, and takes calcium, but without being able to do weight-bearing exercise, her bones don't improve.

Is there any way for a person like this to get impact exercise? Could some sort of vibrator help? She can't stand on her legs. I know she can probably improve her arms (using bands, etc). She seems to be a candidate for Forteo injections, but I wonder if that would help, lacking the ability to walk? She's only about 65, so I would hate to see her get any worse.

Now I only need to think of Becky and I'm very motivated to get on my treadmill - no excuse! I've recommended she see my rheumatologist, and also consider taking strontium citrate, as I believe it may strengthen the bones.

Tom