Bones and joints are always under mechanical loading a key concept in understanding bone metabolism. Among the most common diseases of bones and joints in the elderly are osteoporosis and joint osteoarthritis. Dynamic changes in mechanical loading give rise to problems resulting in stenosis of the spinal column at the cervical, thoracic, and lumbar levels. Mechanical loading also accelerates joint destruction caused by inflammation from such conditions as chronic rheumatoid arthritis. An understanding of mechanical loading is essential therefore to clinicians, basic researchers, and engineers working with bones and joints. Providing up-to-date research and clinical findings, the contents of this volume are from the papers, symposia, and special lectures presented at the 12th Annual Meeting of the Orthopaedic Research Meeting of the Japanese Orthopaedic Association in Niigata, in October 1997.