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Cohort 2

Oliver Chalmers

Title: Developing a biomechanical diabetic foot ulceration risk model.

Supervisor: Dr Daniel Parker

Co-Supervisors: Professor Chris Nester, Dr Yeliz Prior

Background and Rationale: Diabetes prevalence is at epidemic levels and continually rising (Zhang et al., 2020). It is now believed that every 30 seconds a lower limb is amputated as a consequence of diabetes (Singh, 2005), and in 85% of these cases, amputation was preceded by a diabetic foot ulceration (DFU) (Lepäntalo et al., 2011).  DFU’s represent the highest cause of hospitalisation in people with diabetes (Lepäntalo et al., 2011), an individual’s lifetime risk of DFU development is 15-25% (Armstrong et al., 2017). Once ulcerated recurrence rates are 40% within a year and up to 65% five-years post healing (Armstrong et al., 2017). Mortality rates after the onset of an initial DFU are higher than many common cancers, reported to be between 30% and 55% (Armstrong et al., 2020). The alarmingly high recurrence and mortality rates frame the context for my PhD; primary and secondary prevention of DFU’s is critical if we wish to prevent amputation, and ultimately death. The optimal strategy for prevention is to predict and monitor an individual’s future risk of developing a DFU. Although the aetiology of ulceration is complex, an interaction with a patho-mechanical pathway is typical in ulcer development. However, the current biomechanical risk model, that primarily focuses on peak pressure, has failed to predict ulceration events (Waajiman et al., 2014) or correlate with sites of ulcer incidence (Veves et al., 1998; Ledoux et al., 2013). This has led to calls for refinement of current biomechanical markers of risk, with a need for an understanding of all mechanical factors at play in ulceration development (Lazzarini et al., 2019; Yavuz, 2021).

Aims:

Aim 1: To investigate the real-world activity profiles of patients with different ulceration risk status.

Aim 2: To investigate the influence of a number of representative real world physical activities on both shod and barefoot plantar pressure and shear in patients with different ulceration risk status.

Aim 3: To develop a model of diabetic foot ulceration risk based on the interaction between plantar pressure profiles, physical activity, and clinical status.