Effect of Work Boot Characteristics on Vibration Transmitted to Workers’ Feet and Subjective Discomfort

Abstract

The objective of this study was to evaluate vibration transmissibility to the foot, and subjective reports of discomfort, when randomly standing on four different outsoles and three different insole materials. Tests were performed with twenty participants standing on seven different materials fixed on the steel platform of an electrodynamic shaker. Vibration transmissibility from the vibration platform to ten anatomical locations on the foot was measured with a laser Doppler vibrometer. After each test, participants were asked to report subjective discomfort on a scale of 1 to 10. The reported discomfort was correlated with the softness of the material, while the correlation between the vibration transmissibility from 10–200 Hz was extremely poor. Therefore, improved exposure measures are required to document exposure characteristics as relying on subjective reports of discomfort is not sufficient to determine if a worker is exposed to vibration levels associated with elevated injury risks.