R. Kayastha, K. Kisi, J. Tate
Texas State University,
United States
Keywords: job-specific insole design, plantar pressure analysis, construction roofers, work-related musculoskeletal disorders (WMSDs), occupational safety and health
Summary:
The construction industry remains one of the most dangerous professions in the United States, with 1,075 worker fatalities in 2023, where 39.2% of them are from falls, slips, and trips. Roofers spend long hours on steep, uneven surfaces with various postures like kneeling, stooping, walking, standing, and balancing under hot and tiring conditions. Repetitive strain from such postures leads to work-related musculoskeletal disorders (WMSDs), chronic pain, and instability that often contribute to serious falls. Despite these challenges, most safety shoes still use generic insoles that fail to support the unique demands of roofing work. They cannot distribute pressure properly according to the foot during a sloped of awkward task, Although plantar pressure mapping has been widely used in sports and rehabilitation, its application to construction safety and footwear design is very limited. Only a few studies have examined how roof slope, posture influence foot pressure during actual roofing tasks. This study aims to close that gap by developing job-specific insoles that adapt to the way roofers move or work. The objective are to 1) measure how plantar pressure is distributed under realistic roofing postures and slopes. 2) identify critical stress zones linked to fatigue or pain, and 3) use these findings to guide the material and structural design of supportive, comfort-enhancing insoles. A custom wooden roof mock-up with adjustable slopes of 0°, 15°, and 30° was built to simulate real-world conditions. Twelve participants performed shingle-installation tasks while wearing XSensor pressure-sensing insoles. Pressure data were collected from the toes, metatarsals, midfoot, and heel during kneeling, stooping, standing, and walking. A three-way ANOVA was used to analyze the combined influence of posture, slope, and foot zone on peak pressure, and these results were connected to material properties relevant for insole fabrication. The findings showed that posture has the strongest effect on foot loading. Kneeling produced high stress at the toes and metatarsals, while standing distributed pressure more evenly. As the slope increased, pressure shifted toward the forefoot, raising fatigue and discomfort risks. Even when total pressure dropped slightly on steeper angles, the toe area remained a consistent hotspot, underscoring the need for better forefoot support. Based on these insights, a layered insole concept was developed using PU/Graphene-Oxide foam for cushioning, High-Performance Hydrogel (HPHG) for comfort, PDMS for flexibility, a ZnO antimicrobial finish for hygiene, and Phase-Change Materials (PCM) for thermal regulation. Overall, this research creates a practical, data-driven foundation for designing ergonomic insoles specific to roofing tasks. It can help lower WMSDs, fatigue, and fall risks while improving worker safety and productivity. The same approach can benefit other high-risk trades—such as solar installers, carpenters, and waterproofing workers—and offers strong potential for collaboration with footwear manufacturers and safety programs aiming to protect those who build our world.