After a long recovery from a near collision in 2013 with some feral hogs in Texas, I found myself not only 3cm shorter but unable to ride the same way I had ridden before. I had three bikes that I rode fairly regularly and all before the accident were set up just the way I liked them. After the accident ridding was painful. I had to adjust the way I ride and more than that my technique. Now days as I get older and slower and weaker I am making adjustments again.

My suggestion is that you make the adjustments slowly. For low back pain try raising your bars about 1 to 2cm. Also lower your seat about 1 cm. Then ride, ride, ride before making adjustments again. Make all your adjustments slowly over a long period of time and ridding. I found that for my low back pain I had to move the bars up 4.5cm (that's allot!) and move my seat down about 1.5cm. I also went to Bull Horn handle bars cause I am no longer able to use the drops effectively. All in all be sure that you make your adjustments small and slowly with a good amount of ridding in between. Good Luck...