I used to feel it quite a bit in my lower back until I put on my mini apps (monkeys) and my springer seat. Since I did that I haven't had any lower back problems.
If you don't want apes or the expense of changing over to them try this it worked for me and it’s free. Loosen the 4 handle bar clamp bolts a little so the bars turn but won’t flop freely. Each side will turn independently. Sit on the bike and turn the handlebars so they are closer to you making sure they are even. Tighten the 4 bolts and turn the controls around to where you like them. I was able to bring the bars back about 2 inches so I'm not reaching out as far and had less back strain.