Is It Time to Consider Soft Tissue as a Pain Generator in Nonspecific Low Back Pain?

Abstract

Soft tissue pain, although a common human experience, is generally ignored in pain curricula, in part due to our ignorance of the underlying pathophysiologic mechanisms. Dr. Siegfried Mense, in his plenary presentation at the American Academy of Pain Medicine (AAPM) 32nd Annual Meeting, presented his groundbreaking basic science research on the effects of psychological stress on nociceptive neurons [1]. His animal model has also elucidated the role of sensitization of dorsal horn neurons in the pathophysiology of chronic nonspecific low back pain [2]. Longstanding nociceptive input results in activation of dormant synapses, resulting in pain at sites distant from the primary tissue injury. This explains the clinical picture of muscle-to-muscle referred pain—such as the presentation of gluteal pain in a patient with a lumbar erector spinae trigger point. In an animal model, inflammation of the multifidus muscle results in expansion of the receptive field to the thoracolumbar fascia over time. Focal tissue injury eventually causes pain in a more extensive distribution through heterosynaptic facilitation. In an animal model …