Another hazard for your back are the shock waves which travel up your spine when you walk, known as heel strike. A real find for our patients has been the shock-absorbing shoe insert. A cheap but very effective solution. 　　Finally, a word about the state-of-the-art relief- the TENS machine-a small battery-powered gadget which delivers subliminal electrical pulses to the skin. Our experience indicates that your money is better spent on the more old-fashioned remedies