Neuromotor Effects of Whole Body Horizontal Vibration

Low back disorders are very common affecting up to 80% of the population in their lifetime [1]. Whole body vibration (WBV) exposure has long been identified as an important risk factor for low back disorders in industrial workers [2]. A potential mechanism has been proposed by which vibration may lead to injury. Namely, vibration-induced losses in proprioception may lead to inappropriate stabilization and poor dynamic control of the lumbar spine [3]. Increases in proprioceptive errors and in delays in neuormotor response have been demonstrated with 5 Hz, vertical seatpan vibration [3]. While vertical vibration exposure is a common occupational exposure, in some cases, such as off road vehicles and construction vehicles horizontal (fore-aft) vibration may dominate [4]. In this study, the objective was to investigate how the whole body, horizontal, seatpan vibration affects muscle response and to compare these results with the previously studied whole body vertical vibration.