I suffer with my back on a regular basis, popping discs out is all too regular and lower back pain a constant burden. I have been hampered the last few months after putting my coccyx out along with my normal discs after an over the bars off down Garbon Pass (I landed chest first on a rock and bust my ribs, the impact knocking my back out). My Osteopath gave me the green light to go off-road again last week but my lower back is still giving me trouble. I look forward to reading Alan’s article, in the meantime I my join the email list. I have been advised to use stretching exercises and have just this week have ordered a Pilates "Back Care Conditioning Kit" from Wiggle (£24.99). I am hopeful that this will be of some benefit, the stretches I have done so far do seem to of helped.
I know this is probably pretty obvious, but is your saddle too high? Lower back problems are often caused by the hips 'rolling' by over-reaching. Keeping saddles too high seems to me to be a very common error, even with very experienced cyclists.
On the subject of pilates and t'ai chi, I think its more important to have a good teacher than worrying about which discipline to use. In my experience there is so much cross-fertilisation of ideas between yoga/pilates/tai chi that its often hard to tell the classes apart. They are all good, but I think pilates has an edge. But then again, Lance is a yoga fan so presumably he knows what he's about.
A very simple exercise I was shown by a physio for back compression problems is simply reaching to touch your toes while sitting down, but keeping your head firmly looking at the floor - this stretches your back, opening up the vertebrae. He said its useful for allowing the backbone to get back to its 'proper' shape.
My weekend of excersise and stretches did me little good, I ended up with actute locked back after 5 minutes at work on Monday morning after twisting to get a screw :( On the plus side my back held up ok on a short ride on the Sunday. Be wary of work, much better to stick to biking I think.