Enhancing foot ulcer prevention and adherence through personalised footwear and insole design features: insights from N- of-1 trials

Abstract

This study investigates the impact of personalised footwear and insole design and modification features on offloading efficacy and patient adherence in people at risk of diabetes-related neuropathic plantar forefoot ulceration. This study involved a series of non-randomised, unblinded N-of-1 trials with 12 participants who had a history of neuropathic plantar forefoot ulcers recruited from three sites in Sydney, Australia. Barefoot and in-shoe plantar pressures were measured using Mobilemat™ and F-Scan® plantar pressure mapping systems by TekScan® (Boston, USA). Adherence to footwear use was captured using participant self-report. Other outcome measures were participant preference toward footwear, insole design and quality of life. The study identified foot-specific pressure thresholds crucial for effective offloading and ulcer prevention. It showed that the current plantar pressure threshold (<200 kPa or >30% reduction) recommended by the guidelines may not apply to all participants. Reulceration prevention may require a pressure threshold as low as 103 kPa at one site and as high as 352 kPa at another site in the same participant to keep the individual foot in remission. It underscores the significance of considering individual participant's factors such as the site of amputation, current activity level, and the use of mobility aid. The recommended footwear needs to meet the criteria for the participant's intention of use, whether for outdoor use for walking, shopping, medical appointments, social or religious events, occupational purposes or indoor use. In these populations, considering indoor-specific footwear design and options helps to increase adherence and reduce the risk of ulcer occurrence and recurrence. Moreover, factors such as comorbidities, biomechanics, and adherence significantly impact ulcer prevention outcomes. Participant-centric footwear designs that fit individual participants' needs are emphasised as a key strategy to enhance adherence, influenced by social support and healthcare involvement. The study advocates for prioritising patient-centric device designs to achieve therapeutic success. However, further research is needed to investigate the effectiveness of these parameters in improving offloading and adherence, thereby promoting physical and emotional health and overall well-being.