Development of a Novel Translational Model of Vibration Injury to the Spine to Study Acute Injury in Vivo.

摘要

There is currently little mechanistic data defining the relationship between whole body or spine vibration, physiology and pain. Considering that pain is tremendous problem, we have developed a novel in vivo model to study how vibration produces chronic pain and the associated effects on tissues and pain cascades. Studies to date have revealed that even 30 minutes of daily vibration for only 7 days is sufficient to induce significant widespread pain that is sustained following the termination of vibration. Moreover, a single day of exposure also induces sensitivity but it is only transient and recovers by 7 days; yet, if a second exposure is introduced after that recovery, the time to recovery is lengthened, suggesting that there is a cumulative effect of even those exposures that might be considered benign. Another finding is that a host of biochemical changes are associated with pain, including modifications in the cellular response of muscle, spinal cord and intervertebral discs. Analysis of transmissibility demonstrates the resonant frequency of the rat spine to be 8 Hz, while analysis of human studies indicates the response of that species is 4 Hz. Together, all of these findings have tremendous implications for both sub-failure spinal injury and pain. They also establish a strong foundation for the remaining studies including additional exposures and defining the time course of the onset and/or resolution of the physiological responses. Continued investigations in these areas, as well as in the mathematical models we have begun to establish will integrate findings across all tasks of this work.