The companion to Volume 1 with the same title and a similar approach: namely, to draw together current understanding of the multifactorial nature of back pain. Both volumes together contain chapters contributed by most of the leading researchers into back pain in the UK. Rather than concentrating on specialist areas such as surgery or the lumbar spine, the emphasis is on understanding the function and failure of the spine and its component tissues. As such it contains material which is applicable to anyone with an interest in any aspect of the spine; from biomechanics to blood flow, epidemiology to economics, nerves to nutrition and everything else in between.