I have been lucky (touch wood) that after a working life and hobbies that entailed digging soil I have never suffered back pain. Earlier on as a youth I was taught how to lift and move heavy objects with the least effort, part of the training as a competitive field gun crew. This morning I was only half listening about back pain and gardening on the BBC and thought at first it was just some 'expert' with a degree in stating the bleeding obvious. But no they have used modern computer graphics and models to find the most efficient way to dig without pulling muscles etc. Worth watching if you have a 'weak' back.