One of my lumbars is not connected to my pelvis and causes me trouble now and then,but strangely not on a bike though.Sitting in the saddle holds everything in place and most of the strain stays in the legs.I road ride and some rails-to-trails.No mountainbiking for me.I think I'm more comfortable on the bike than I am standing or sitting in most chairs. Hope your doc gives a thumbs up to cycling,it's been a BIG plus in my life!