The development of foot ulcers is a common consequence of severe diabetes. Due to vascular disorders and impeded healing caused by the disease, most foot ulcers have been reported to be affected by body weight and progress with time. Also, abnormal distribution of plantar pressures has been observed to cause the formation of additional ulcers, which may collectively lead to traumatic amputations. While a study of such pathophysiology is not possible through experiments, a few computational modelling works have investigated diabetic foot ulcers. To date, ulcers with a few sizes and locations have been studied, and their effect on the plantar stresses has been quantified. In this work, we have attempted to study the effect of all possible ulcer locations on the generated plantar peak stresses and peak stress locations where additional ulcers may form. Also, the effect of ulcer location on the possible ulcer growth was investigated. A full-scale foot model was developed and a total of 52 ulcer locations were simulated separately, with standing and walking loads. The generated stresses were normalised with the foot size and statistically analysed to develop novel formulations for predicting peak plantar stresses and their locations for any known ulcer location. The results from this study are anticipated to provide important guidelines to doctors and medical practitioners for predicting foot ulcer progression in diabetic patients with existing ulcers and allow the administration of timely preventive interventions.

Slippery flooring often leads to unintentional slips and falls, which results in traumatic injuries. To reduce slipping risks, adequate traction at the shoe and flooring contact is essential. In addition, viscous slippery contaminants like water or oil reduce a floor’s traction performance and increase slipping hazards. In this work, the effect of commonly available protective floor coatings on the traction performance of safety-labelled shoes was extensively studied. The study included three floor coatings, namely acid-based etchant coating, epoxy floor paint, and polyurethane, which were tested across five safety shoes. The coated floorings were tested using a robotic slip-testing device in dry and in the presence of water and machine oil—as separate contaminants. The application of floor coatings produced varying surface roughness for the flooring. Significant traction was generated by the etchant coating for the dry flooring, epoxy coating for the wet flooring, and polyurethane coating for all flooring conditions. A comparison of uncoated and coated floorings showed a high effectiveness of generating traction with epoxy coating on wet flooring and polyurethane coating on both wet and oily conditions. The study results are novel and are anticipated to provide valuable guidelines for the selection of slip-resistant coatings for different slippery floorings, and to reduce risks related to slips and falls.

Traumatic injuries caused due to slipping and falling are prevalent in India and across the globe. These injuries not only hamper quality of life but are also responsible for huge economic and compensation burdens. Unintentional slips usually occur due to inadequate traction between the shoe and floor. Due to the economic conditions in low and middle-income countries, the public tends to buy low-cost footwear as an alternative to costly slip-resistant shoes. In this study, ten high-selling formal shoes under $25 were considered. These shoes were tested on three commonly available dry floorings and across contaminated common floor surfaces (i.e., water and floor cleaners). The traction performance of the shoes was quantified by using a biofidelic slip tester. The majority of formal shoes were not found to produce the slip-resistant performance across common slippery surfaces. Shoes with softer outsoles exhibited increased slip-resistant performance (R² = 0.91). Shoe outsoles with less-to-no treads at the heel region showed poor traction performance as compared to other shoes. The apparent contact area was found as an important metric influencing the slip risks in dry and wet slipping conditions (R² = 0.88). This research is anticipated to help the public and footwear manufacturers select safer shoes to reduce slip-and-fall incidents.

Slips and falls are among the most serious public safety hazards. Adequate friction at the shoe–floor contact is necessary to reduce these risks. In the presence of slippery fluids such as water or oil, the footwear outsole is crucial for ensuring appropriate shoe–floor traction. While the influence of flooring and contaminants on footwear traction has been extensively studied across several outsole surfaces, limited studies have investigated the science of outsole design and how it affects footwear traction performance. In this work, the tread channels of a commonly found outsole pattern, i.e., horizontally oriented treads, was varied parametrically across the widths (i.e., 2, 4, 6 mm) and gaps (i.e., 2, 3, 4 mm). Nine outsole designs were developed and their traction, fluid pressures, and fluid flow rates during slipping were estimated using a mechanical slip testing and a CFD-based computational framework. Outsoles which had wider tread (i.e., 6 mm) surfaces showed increased slip risks on wet flooring. Outsoles with large gaps (i.e., 4 mm) exhibited increased traction performance when slipped on wet flooring (R² = 0.86). These novel results are anticipated to provide valuable insights into the science of footwear traction and provide important guidelines for the footwear manufacturers to optimize outsole surface design to reduce the risk of slips and falls. In addition to this, the presented CFD-based computational framework could help develop better outsole designs to further solve this problem.