Improving Footwear for Underground Coal Miners

Background: Underground coal miners are required to remain on their feet for most of their 8-12 hour working shift. The work boots currently worn during these long shifts are not only uncomfortable but potentially contribute to the high incidence of lower limb injuries sustained in this occupation. Despite the negative consequences associated with inappropriate footwear, no published research was available that had systematically examined mining work boot fit and comfort and the interaction between how mining work design affects lower limb biomechanics while miners walk. Research Question: The overall aim of this thesis was to identify design features that influenced the fit and comfort of mining work boots and affect the way individuals walked in order to develop evidence-based guidelines to improve the design of footwear for underground coal miners. Methods: A series of three studies, presented in three parts, were conducted to address the overall thesis aim. Part I aimed to assess current mining work boot satisfaction in relation to the work-related requirements of underground coal mining (Chapter 2) and to identify specific work boot design features that warranted further investigation (Chapter 3). Part II aimed to assess current work boot fit (Chapter 4) and identify how work boot fit could be improved (Chapter 5). Part III described the boot designs that have previously been shown to influence gait (Chapter 6) and then the effect of the systematic alteration of these design features on the comfort (Chapter 7) and slip (Chapter 8)/trip (Chapter 9) risk of participants walking on simulated underground coal mining surfaces. Finally, the three studies were used to create more specific boot design recommendations for underground coal miners (Chapter 10). Major Conclusions: It is apparent current underground coal mining work boots do not provide acceptable fit, comfort or functionality while miners walk. Not only do miners find their current work boots uncomfortable, but quantitative evidence shows the shape of miners’ feet do not match the shape of the inside of their work boots. Miners continue to report a myriad of foot problems and lower limb injuries that they attribute to their current work boots. Overall, underground coal mining work boots need to be redesigned. Specifically, the forefoot and heel area need to be made wider and there should be variable flexibility between the boot shaft and boot sole. Additionally, when designing future work boots for underground coal miners, interactions between the design features and surfaces walked on need to be considered because the boot shaft and sole interact to influence plantar pressures, lower limb muscle activity and lower limb motion while miners walk. By incorporating evidence-based design recommendations, the fit and comfort of underground coal mining work boots could be substantially improved, thus improving worker satisfaction and potentially decreasing the high incidence of lower limb injuries experienced by underground coal miners