Glad to hear you are varying your workouts, impact will help those bones.
When is your MS150? If you husband keeps walking and staying active I think it is still feasible. Did the doctor say it was over use? Does his bike fit properly, I cannot tell you how bad my knees were before my bike fit. In fact it hurts just to think about it.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan