Evaluating Vibration Exposure and Lumbar Disc Injuries
Background
A man who had been working for the railroad since 1970 claimed that he was exposed to years of repetitive, vibratory, physically stressful, and ergonomically awkward job duties. Specifically, he had to sit for extended periods of time on locomotive seats that were "ergonomically awkward and unsafe" and exposed him to dangerous levels of whole-body vibration (WBV).He claimed that his diagnosed lumbar disc bulges were a result of these conditions.
Process
Explico was retained to inspect the locomotive in question and measure the vibration exposure during two 8-hour shifts. Our team of experts conducted this in order to specifically determine if the vibration exposure fell within the health exposure guideline limits established by the International Organization for Standardization (ISO)2631-1 and ISO 2631 Part-5 (2004) standards. The purpose of testing against these standards was to determine the probability of an adverse health effect after a certain number of years of exposure or at a “lifetime” of exposure. As part of the inspection, our experts placed a seat pad accelerometer on the engineer’s seat and an additional accelerometer on the floor of the locomotive. The position and speed of the locomotive was also simultaneously recorded with a GPS sensor.
Results
Our experts determined that the vibration the plaintiff experienced during his career as an engineer was below accepted thresholds established by the ISO. It was demonstrated that the level of vibration the plaintiff experienced during his career was safe from a biomechanics perspective. There is no scientific basis to conclude that the vibration exposure caused or contributed to his lumbar spine conditions. The case settled prior to going to trial.
