Analysis of Whole-Body Vibration Using Electric Powered Wheelchairs on Surface Transitions.

Jorge Candiotti,Rory Cooper,Sivashankar Sivakanthan,Ahlad Neti

doi:10.3390/vibration5010006

Abstract

Wheelchair users are exposed to whole-body vibration (WBV) when driving on sidewalks and in urban environments; however, there is limited literature on WBV exposure to power wheelchair users when driving during daily activities. Further, surface transitions (i.e., curb-ramps) provide wheelchair accessibility from street intersections to sidewalks; but these require a threshold for water drainage. This threshold may induce high WBV (i.e., root-mean-square and vibration-daily-value accelerations) when accessibility guidelines are not met. This study analyzed the WBV effects on power wheelchairs with passive suspension when driving over surfaces with different thresholds. Additionally, this study introduced a novel power wheelchair with active suspension to reduce WBV levels on surface transitions. Three trials were performed with a commercial power wheelchair with passive suspension, a novel power wheelchair with active suspension, and the novel power wheelchair without active suspension driving on surfaces with five different thresholds. Results show no WBV difference among EPWs across all surfaces. However, the vibration-dose-value increased with higher surface thresholds when using the passive suspension while the active suspension remained constant. Overall, the power wheelchair with active suspension offered similar WBV effects as the passive suspension. While significant vibration-dose-value differences were observed between surface thresholds, all EPWs maintained WBV values below the ISO 2631-1 health caution zone.

Highlights

There are about 5.5 million wheelchair users in the United States (US) [1]
Results show no significant differences in average whole-body vibration (WBV) (RMS and VDV) values between the commercial EPW, MEBot with active suspension (AS), and MEBot with noAS when driving on surface transitions with different thresholds (Figure 5)
In terms of WBV differences between surfaces, it was found that potholes caused significantly higher RMS values on the commercial EPW compared with the 12.5 cm/m surface roughness (p < 0.001) and the 10◦ ramp without threshold (p < 0.001) (Table 1)

Summary

Introduction

There are about 5.5 million wheelchair users in the United States (US) [1]. Wheelchairs provide independent mobility [2], comfort [3], and quality of life for people with disabilities to participate in communities [4]. Multiple studies have demonstrated that manual wheelchair users are exposed to whole-body vibrations (WBVs) when driving on uneven and rough surfaces for long periods of time [5]. This exposure causes negative effects such as pain in the lower back, neck, and buttocks and increases the rate of muscle fatigue [6,7,8]. Based on an eight-hour exposure, a lower limit was defined at 0.5 m/s2 for RMS and 9.1 m/s1.75 for VDV. ISO 2631-1 (1997) has served as a form of standardized guidance in many studies for WBV exposure

Objectives

Methods

Results

Conclusion