I had cut way back on my mileage and intensity, and the past 14 months or so have been punctuated by the healing and recovery proccesses of several (four) injuries. After the last, I noticed for the first time ever a slight numbness in my fingers when on the hoods. Not really a problem, but I raised my bars .5cm and went to a 1cm shorter stem. Went out for a hammer session on a known route the other day and near the end, my lower back started aching bigtime! It made just being on the bike uncomfortable. Again, this has never happened to me before. Luckily the ache went away within a 15 min. of getting off the bike, so its nothing serious. The suprising thing is how the loss of flexibility just kind of creeped up in a scarey way. I hate intense stretching regimens and have never used them, but this situation seems different.