I am not a medical professional, so take my recommendations with a grain of salt, but below is what I have experienced so far:
I also have degenerative disc disease (DDD). Specifically, my lower two discs (L5/S1 and L4/L5) are "dead"; on an MRI scan, they show up as black and weak, whereas the discs higher in the spine are white and healthy. I am 32. I have had low-back issues since 2010, at age 26, when I injured myself while using a leg press machine. Since then I was able to complete a short stint in physical therapy and improve and do a lot of quality fast-paced group riding in late 2011 and all of 2012; complete a cross-USA tour (4,000-plus miles) in 2013 with amazingly little back pain; and continue the quality riding through 2014. But in 2015 and 2016 I have experienced similar muscle pulls/spasms as you mentioned, which have completely debilitated me for days/weeks at a time, and I have only been able to do lots of garbage cycling miles.
Unfortunately, it seems there is no one cure. Just today I got back from an appointment with the most highly respected spine doctor I could find in my area, and he had little reassuring good news. He said that if the discs are in a state of DDD, then they will not get better; they will just deteriorate over time. My doctor did not recommend any surgical fixes to my issues because of my young age and (relatively high) activity level. Of course, I am in pain most of my life, either on the bike or off, ranging from low-level soreness, to quite sore and pained, to excruciating pain during flareups of the injury, so even though I am trying to continue to be highly active, I feel like ****!
The main recommendations to deal with DDD and being a cyclist are:
1. Lose weight if you are overweight -- and don't smoke, as that can make discs problems in particular worse. Although I am not overweight by "normal people" standards, I am about 20 pounds heavier than I was in 2013 (some of that being extra muscle, not fat), so I am going to try to recommit to being as light as possible, as it can only help things.
2. Strengthen core muscles to reduce the load placed on the lower spine, and exercise to increase flexibility. You are likely a candidate for physical therapy. I just finished up eight weeks of therapy; I do feel better and can usually ride leisurely for about 30 minutes before any indication of soreness or pain, but of course that's still not remotely close to where I want to be. Still, maybe several more months of doing the strengthening and stretching will pay off. It is now almost winter, so I can commit to doing that stuff during the cold months.
3. Try an inversion machine or traction to reduce pain. I'm going to try the former; a friend of mine with disc problems recommends it.
4. Try a long-acting NSAID like meloxicam -- which I have just heard about and am going to try soon, at my doctor's recommendation.
5. Steroid injections. I have always heard about them, never tried it. If I do any longer tours, I will likely try it. A Band-Aid fix, but better than nothing.
6. Adjust your seated posture if you spend a lot of time sitting. I work a desk job and my posture was horrible and probably contributed to my issues.
7. Alter your fit. For your situation, before you go all out and replace your bike, you could try an adjustable stem and set it to the most upright position. I recently installed a Ritchey adjustable stem for my Surly Long Haul Trucker. It has helped me somewhat, but it is mainly a Band-Aid to my overall problems. However ... I do wonder if an upright posture is better over the long term. In my non-bike life, I feel much more at ease when I'm in a plank-like position (which is more similar to an aero cycling fit) than when sitting in a chair (which is like an upright bike position). I'm not sure.
As for recumbents, yeah, I guess they probably are better for low-back pain. I have never tried one, though. Once you feel well enough to ride one, you could rent one for a day and compare it your regular bike. If the recumbent feels good and the upright bike doesn't, that is valuable information. My doctor says I may have to stop cycling because of the bent-forward position being back for my situation, which is pretty scary.
I am also curious how old you are, what you do for a living (sit, work construction, etc.), what your previous stretching regimen was like, etc. That could reveal problems as to why you developed DDD in the first place. In my case, as far as I know, it was a single traumatic incident.
The main thing I am hoping for now is that my low back and ab muscles were so weak -- due to no substantial stretching or strengthening of them since mid-2015 -- that I can make huge strides via physical therapy and correct things, and get back to where I was in 2012-2014.
Sorry for the long and somewhat depressing-sounding post! I think the prognosis for severe DDD is not good, but I am hoping the physical therapy can win out in the end. Feel free to reply or private message me if you want to discuss further!
Last edited by ptotheatsign; 11-08-16 at 04:53 PM.