Research shows miners can be exposed to foot-transmitted vibration (FTV) when
operating various pieces of underground mining equipment, and case reports suggest
workers are experiencing symptoms similar to those of hand-arm vibration syndrome in
their feet. A field study was conducted to measure and document FTV exposure
associated with operating underground mining equipment, and probable health risks were
determined based on both ISO 2631-1 (1997) for WBV and ISO 5349-1 (2004) for HAV.
Seventeen participating operator’s also reported musculoskeletal discomfort. Seventeen
male participants ranging between 24-61 years of age, with an average height and mass of
175.0cm and 88.2kg volunteered for the study. Seventeen pieces of equipment were
tested; 1 locomotive, 1 crusher, 9 bolter drills (4 scissor platforms, 2 Maclean, 2
Boart/basket, and 1 RDH), and 6 jumbo drills.
Including all seventeen pieces of underground mining equipment, the vibration
acceleration ranged from 0.13-1.35m/s2 with dominant frequencies between 1.25-250Hz
according to ISO 2631-1. According to ISO 5349-1 vibration acceleration ranged from
0.14-3.61m/s2 with dominant frequencies between 6.3-250Hz. Furthermore, the
magnitude of FTV measured on the jumbo drills with grated platforms (#5 and #6) was
less than FTV measured from the jumbo drills with, solid metal surfaces. Additionally,
twelve of the seventeen equipment operators indicated a complaint of discomfort in their
lower body (specifically at the level of the knee or lower). The health risk analysis based
on ISO 2631-1 indicated that one operator (bolter drill #9) was exposed to vibration
above the criterion value, while the health risk analysis based on ISO 5349-1 indicated
iv
that two operators (jumbo drill #1 and bolter drill #1) were exposed to vibration above the
criterion value. Operators reported very severe or severe discomfort; however, the same
operators were not the operators of the equipment with FTV exposure levels above the
ISO standards, leaving evidence to suggest that the standards are not properly assessing
injury risk to vibration exposure via the feet. Future research is needed to develop a
standard specific for FTV and to determine the link between early musculoskeletal injury
reporting and the onset of vibration white foot. To do so, a better understanding of the
biodynamic response of the foot to FTV is needed.
A laboratory study was conducted to 1) measure and document transmissibility of FTV
from (a) floor-to-ankle (lateral malleolus), and (b) floor-to-metatarsal, during exposure to
six levels of vibration (25Hz, 30Hz, 35Hz, 40Hz, 45Hz, and 50Hz) while standing, and 2)
to determine whether independent variables (vibration exposure frequency, mass, arch
type) influence transmissibility (dependent variable) through the foot. A two-way
repeated measures analysis of variance (ANOVA) was conducted. There was a
significant interaction between transmissibility location and exposure frequency (λ =
0.246, F (5,25) = 15.365, p = 0.0001). There were significant differences in mean
transmissibility between the ankle and metatarsal at 40Hz [t(29) = 4.116, p = 0.00029],
45Hz [t(29) = 6.599, p = 0.00000031], and 50Hz [t(29) = 8.828, p = 0.000000001]. The
greatest transmissibility at the metatarsal occurred at 50Hz and at the ankle (lateral
malleolus) transmissibility was highest from 25-30Hz, indicating the formation of a local
resonance at each location.
v
Future research should focus on identifying resonance frequencies at different locations
on the feet. This information is needed to develop an exposure guideline to help protect
workers from exposure to FTV, and to develop personal protective equipment capable of
attenuating harmful FTV exposure frequencies.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OSUL.10219/2013 |
| Date | 30 July 2013 |
| Creators | Goggins, Katie A. |
| Publisher | Laurentian University of Sudbury |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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