# Effects of Multi-axial Whole Body Vibrations on Postural Stability

> **NIH ALLCDC R21** · OREGON STATE UNIVERSITY · 2020 · $146,654

## Abstract

Abstract
 Professional heavy equipment vehicle operators suffer from a high prevalence of occupational injuries
and illnesses. Among all injuries, fall-related injuries during vehicle ingress and egress have accounted for a
large proportion of both fatal and non-fatal injuries in the US. The rate of these fall-related injuries has been
much higher (up to 8 times) during egress as compared to ingress of vehicles. A likely cause for the
disproportionally high fall-related injury rates during egress is a loss of postural stability. Prolonged exposure to
Whole Body Vibration (WBV) compromises postural stability and thereby can increase the risks of falling. Off-
road heavy equipment vehicle operators are particularly at a greater risk, because they are exposed to a higher
level of WBV as compared to on-road vehicle operators. Furthermore, the predominant WBV exposure axis in
off-road heavy equipment vehicles is not necessarily limited to the vertical (z-axis), but can often include
significant fore-aft (x-axis) and/or lateral (y-axis) components. The nature of the additional impact of multi-axial
WBV exposure on postural stability is poorly understood at present. Moreover, there is a lack of scientific studies
to evaluate effective engineering interventions to mitigate multi-axial exposures during vehicle operation.
 We propose a repeated-measures laboratory study to identify the relative impacts of single- and multi-
axial WBV exposure on postural stability, and to determine the effectiveness of a newly-invented innovative
engineering control to mitigate multi-axial WBV exposure and associated postural instability. WBV exposures
will be simulated in the laboratory by replicating actual field-measured vibration profiles from off-road heavy
equipment vehicles on a motion platform. To determine whether multi-axial WBV exposure will have a greater
impact on postural stability compared to vertical-dominant WBV, we will assess functional limits of stability,
postural stability in standing balance, and anticipatory postural adjustments preceding functional tasks such as
level gait and stair descent. We will also test whether the use of a multi-axial suspension seat will alleviate the
adverse effects of multi-axial WBV on postural stability measures more effectively than a single-axial passive
suspension seat. Results of this project can support future efforts to reduce the risks of fall-related injuries and
therefore improve the occupational health and well-being for off-road vehicle operators. This project supports
the NIOSH National Occupational Research Agenda, especially for the transportation and mining sectors, and
the Musculoskeletal Health Research Priorities (NOT-OH-16-012), by clearly delineating the relative impacts of
single- and multi-axial WBV exposures on postural stability among off-road vehicle operators, providing the
neurophysiological underpinnings relating the type and extent of WBV with the risk of fall-related injuries, and by
evalua...

## Key facts

- **NIH application ID:** 10006491
- **Project number:** 5R21OH011538-02
- **Recipient organization:** OREGON STATE UNIVERSITY
- **Principal Investigator:** Jeong Ho Kim
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** ALLCDC
- **Fiscal year:** 2020
- **Award amount:** $146,654
- **Award type:** 5
- **Project period:** 2019-09-15 → 2021-09-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10006491

## Citation

> US National Institutes of Health, RePORTER application 10006491, Effects of Multi-axial Whole Body Vibrations on Postural Stability (5R21OH011538-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10006491. Licensed CC0.

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