Effects of seated whole-body vibration on the lumbar spine : a Sprague-Dawley animal model

Abstract

Seated whole-body vibration (WBV) is often experienced by individuals, most commonly as vehicle occupants. Understanding the long-term health implications of WBV is crucial for assessing human well-being. This study investigates the effect of seated WBV on bone and intervertebral disc (IVD) properties in the lumbar spine using a novel seated Sprague-Dawley rat model. Ten-week-old male Sprague-Dawley rats (n = 24) were used. The experimental group (EG, n = 18) were exposed to WBV in a seated position using a custom designed seated rat vibration apparatus. Control group one (C1, n = 3) were placed in a stationary capsule, while control group two (C2, n = 3) remained in their cages throughout the study. X-ray images were taken weekly to track changes in IVD thickness (also termed IVD height in humans) and lumbar spine superior- and inferior endplate (SEP and IEP) bone mineral density (BMD) during the 8-week period. The applied WBV resulted in significant differences in both the SEP BMD and IVD thickness of the Sprague-Dawley rat lumbar spine towards the end of the test. No notable changes in IEP BMD were observed. The findings align with existing literature on the biological effects of WBV on the lumbar spine, emphasizing the importance of understanding the relationship between seated WBV and lumbar spine BMD and IVD thickness. The novel animal model enables research into understanding this relationship and the relationship between exposure and rest periods, particularly to identify optimal exposure-rest ratios that minimize harmful effects on the spine.