Countering postural posteffects following prolonged exposure to whole-body vibration: a sensorimotor treatment

Abstract

Postural stability of bulldozer operators after a day of work is investigated. When operators are no longer exposed to whole-body vibration (WBV) generated by their vehicle, their sensorimotor coordination and body representation remain altered. A sensorimotor treatment based on a set of customized voluntary movements is tested to counter and prevent potential post-work accidents due to prolonged exposure to WBV. This treatment includes muscle stretching, joint rotations, and plantar pressures, all known to minimize the deleterious effects of prolonged exposure to mechanical vibrations. The postural stability of participants (drivers; N = 12) was assessed via the area of an ellipse computed from the X and Y displacements of the center-of-pressure (CoP) in the horizontal plane when they executed a simple balance task before driving, after driving, and after driving and having performed the sensorimotor treatment. An ancillary experiment is also reported in which a group of non-driver participants (N = 12) performed the same postural task three times during the same day but without exposure to WBV or the sensorimotor treatment. Prolonged exposure to WBV significantly increased postural instability in bulldozer drivers after they operated their vehicle compared to prior to their day of work. The sensorimotor treatment allowed postural stability to return to a level that was not significantly different from that before driving. The results reveal that (1) the postural system remains perturbed after prolonged exposure to WBV due to operating a bulldozer and (2) treatment immediately after driving provides a "sensorimotor recalibration" and a significant decrease in WBV-induced postural instability. If confirmed in different contexts, the postural re-stabilizing effect of the sensorimotor treatment would constitute a simple, rapid, inexpensive, and efficient means to prevent post-work accidents due to balance-related issues.

Changes in postural sway frequency and complexity in altered sensory environments following whole body vibrations

“…In fact previous studies have demonstrated an immediate suppression of reflex activity in response to acute WBV (Martin, Roll, & Gauthier, 1986) followed by recovery within 1-30 min (Armstrong et al, 2008;Kipp, Johnson, Doeringer, & Hoffman, 2011;Roll, Martin, Gauthier, & Mussa, 1980). Additionally, when exposed to longer period of vibration the responsiveness of the sensor motor system was shown to be ''recalibrated'' with voluntary movements of the muscles nearly immediately (Oullier et al, 2009). Although the current studies recovery period of 10-20 min falls within this reported period the current study measured a more global neuromuscular response similar to that of Oullier and colleagues (Oullier et al, 2009).…”

“…Additionally, when exposed to longer period of vibration the responsiveness of the sensor motor system was shown to be ''recalibrated'' with voluntary movements of the muscles nearly immediately (Oullier et al, 2009). Although the current studies recovery period of 10-20 min falls within this reported period the current study measured a more global neuromuscular response similar to that of Oullier and colleagues (Oullier et al, 2009). However, unlike previous investigations the present study assessed postural control in altered sensory environments further necessitating the involvement of the somatosensory systems.…”

“…While other studies have reported negative effects in individuals exposed to vibrations for hours to hundreds of hours, and in many cases while assuming a seated position increasing the degree of vibration exposure to the spinal column (Oullier et al, 2009;Seidel, 2005). Given the range of results associated with WBV research (Cochrane, 2011) and the potential for WBV as an enhancement tool to overall motor function further inquiry is needed.…”

Vibration as an exercise modality: how it may work, and what its potential might be

“…One might therefore expect that vibration, as an interfering stimulus, should lead to an immediate deterioration of balance (Oullier et al 2008). It seems, however, that the mode of vibration application, as well as people's age need to be considered.…”

Measurement and Analysis of Vibration of Operator in Universal 650, Massey Ferguson 285 & MF 299 Tractors

“…A sensorimotor treatment based on a set of customized voluntary movements is tested to counter and prevent potential post-work accidents due to prolonged exposure to whole body vibration, [9]. Exposure to whole body vibrations predicts subsequent disability pension retirement continue reduction of whole-body-vibrations may reduce the number of new cases of disability pension, [2].…”