It is estimated that there are 5.6 million people with diabetes in the UK (Diabetes UK, 2024). Between 19% and 34% of individuals with diabetes will develop diabetic foot ulcers (DFUs) in their lifetime (Armstrong et al, 2017). DFUs take significant time and treatment to heal and 85% of amputations being preceded by a foot ulcer (Pecoraroet al, 1990). Lower limb amputation risk is 23 times higher than that of a person without diabetes (Brownrigg et al, 2013). Current DFU prevention methods are inadequate and approximately 40% of ulcers recurring within 1 year of ulcer healing, 60% within 3 years, and 65% within 5 years (Armstrong et al, 2017). DFUs and amputations also have a significant environmental cost due to patient/clinician travel and consumables used in assessment and treatment.
Path Active insoles (Walk With Path; Figure 1) measure changes in temperature and pressure which can be pre-ulcerative indicators (Saliba Thorne et al, 2021). They are not currently available commercially, although the aim is to market these later in 2025. The insoles link via Bluetooth to an app on the patient’s phone (Figure 2) and via Wi-Fi to a clinician’s dashboard (Figure 3). The app and dashboard alert users and their healthcare professionals when DFU risk is high. This alerts users to offload their feet to prevent ulcers and allows clinicians to personalise their appointments according to individualised risk profiles. The app gives instructions to the patient if the alert is triggered.
Preventing DFUs using Path Active smart insoles could reduce morbidity and mortality in people with diabetes, reduce costs for the health service and help the NHS towards net zero carbon emissions.
This study looked at patient and clinician use and perception of Path Active smart insoles.
Materials and Methods
User testing
Five participants who were over 18, with either type 1 or type 2 diabetes with no current foot ulceration who own a smartphone were recruited for user testing at the Royal Free Hospital, London. Users were asked to use the Path Active insoles, linked to the app and clinician’s dashboard, for a week. Before and after Path Active use, users were provided a questionnaire to investigate their user experience and the EQ-5D-5L questionnaire to investigate any changes in quality of life (QoL).
Carbon footprint analysis
Carbon footprint analysis was performed by an independent organisation, Intertek. A complete cradle-to-grave lifecycle analysis for Path Active was carried out to estimate the carbon footprint of producing, distributing, and using a pair of insoles. This was compared to their estimated carbon footprints for the following DFU scenarios:
- Scenario 1: Normal evaluation of a moderate or high-risk patient without an ulcer developing.
- Scenario 2: Non-infected superficial ulcer.
- Scenario 3: Infected superficial ulcer.
- Scenario 4: Infected ulcer penetrating tendon or capsule.
- Scenario 5: Infected ulcer penetrating bone or joint.
Results
User experience
User testing demonstrated that users were technologically ready and able to implement Path Active in their day to day lives. Four out of five users stated that they were definitely or probably comfortable with using phone apps. All stated that they would definitely be comfortable with data being collected by Path Active and shared with their healthcare providers.
Following Path Active use, all five agreed that they would definitely examine and offload their feet if recommended by the device. Users also tended to show an increase in thoughts and concerns about ulceration after using Path Active (Figure 4), although this trend was not statistically significant. This suggests that Path Active may be successful in increasing the users’ awareness of their foot health.
No reduction in EQ-5D scores was observed after one week of Path Active use, suggesting that the use of smart insoles in daily life does not have a negative impact on user quality of life (Figure 5).
Carbon footprint analysis
The independent carbon footprint analysis by Intertek found that found all scenarios other than scenario 1 (no ulcer) had 8–16 times the global warming potential (GWP) of Path Active use (Figure 5).
Discussion
Path Active may increase the users’ awareness of their foot health. Discussions with healthcare professionals have shown that being aware of one’s own risk is a very important aspect of diabetic foot self-care, and hence this is very positive in the mission to prevent ulceration.
A previous study, demonstrated that insoles which monitor plantar pressure alone resulted in a 71% reduction in DFU incidence (Abbott et al, 2019).
Conclusion
This study adds to the literature demonstrating the potential of smart insoles in diabetic foot care.
However, longer term use of Path Active with more participants is needed for further evaluation and this is currently being undertaken in a multicentre randomised controlled trial in the UK. ‘Path Active’ is unique as the only smart, remote-monitoring insole with a net zero analysis.
