Chronic lumbar spine and radicular pain: pathophysiology and treatment.

The lumbar spine forms the foundation and infrastructure of an organic skyscraper equipped with the physiologic capacity to act as a crane for lifting and a crankshaft for walking. Subjected to aging like other "human machinery," the lumbar spine adapts to the wear and tear of gravity and biomechanical loading through structural and neurochemical changes. Many of the changes are maladaptive, resulting in pain, physical and functional disability, and altered neurophysiologic circuitry. Some compensatory reactions are constructive, but others cause more interference with the organism's capacity to cope. A conceptional understanding of the multifaceted structural, biomechanical, biochemical, medical, and psychosocial influences that compose this mix elucidates the complexity of applying effective treatments.