Quote Originally Posted by OakLeaf View Post
How are they on the lumbar spine, though? Seems like it would be really bad, between the seat and not being able to extend your hips?
You've got to get a seat that fits, but I think that's easier than it is for DFs.
There is something that some get termed recumbutt - which I suspect is a lumbar spine issue. It is (almost?) always cured by a more reclined seat. But, then you get neck issues... but you can easily get a neck rest. Just like DF, you have to find what fits you and works for you. It's easier to do with a recumbent than a DF, though.
On my performance bent, I have a somewhat reclined seat and a neckrest - the combo is wonderful. Fast (for slow old me), but comfortable.
On my commuter bike, I have never had any issues with the comfy seat and recumbutt and my seat is upright enough not to need a neck rest.
Other than recumbutt, I've never heard of back/butt/neck issues on a bent.