I was pleased to see this topic mentioned in popular news by Gretchen Reynolds of the New York Times. As mentioned running backwards is not the safest but walking backwards (please do so in wide, flat spaces) does provide a huge opportunity for learning. Moche Feldenkrais was a proponent of walking backwards after Awareness Through Movement lessons. The idea behind this concept is that your body and central nervous system don't recognize patterns of movement that you may usually follow when walking forwards. In an ATM lesson your body learns through movement and when you stand, to integrate, or accept the new organization of functioning, walking backwards helps 'trick' the CNS.