Challenger multihull

My father has been dinghy sailing for years but but over the last couple of years he his back as got worse a second disc has burst in the summer, sitting in a car for more than an hour and he is on a lots of painkillers he next day.He crewed my my dart 18 a couple of times before the last disc burst and found the cat a lot easier on the back then the Devon yawl style boat he had at the time, but he has been looking at the Challenger trimaran has anybody had any experice of these boats and if they would be any good for the problem he faces.We have been tring to contact the assoication but not heard anything back yet.