speaking as a retired occupational therapist, the best protection for your back is strong muscles and avoiding doing things that could damage it!
your employer has legal responsibilities to ensure that you can work in a way that will minimise the risk of injury.
advice for employer and employee here.
http://www.hse.gov.uk/msd/backpain/
I lifted patients before the LOLER regs came in and have the iffy back to prove it. Once your back is damaged, that is it, please be careful.