Cheers. Ordered. I do a bit of backpacking (photo gear can be heavy) and i have back issues. I alwyas backed it like deuter suggests. does the book mention why

Cheers. Ordered. I do a bit of backpacking (photo gear can be heavy) and i have back issues. I alwyas backed it like deuter suggests. does the book mention why the center of gravity needs to be different for sciatica folks? do you stand/walk more than you sit during work hours now?