Offloading and adherence through technological advancements: Modern approaches for better foot care in diabetes

Abstract

Objective:

This manuscript aims to provide a review and synthesis of contemporary advancements in footwear, sensor technology for remote monitoring, and digital health, with a focus on improving offloading and measuring and enhancing adherence to offloading in diabetic foot care.

Methods:

A narrative literature review was conducted by sourcing peer-reviewed articles, clinical studies, and technological innovations. This paper includes a review of various strategies, from specifically designed footwear, smart insoles and boots to using digital health interventions, which aim to offload plantar pressure and help prevent and manage wounds more effectively by improving the adherence to such offloading.

Results:

In-house specially made footwear, sensor technologies remotely measuring pressure and weight-bearing activity, exemplified for example, through applications like smart insoles and SmartBoot, and other digital health technologies, show promise in improving offloading and changing patient behaviour towards improving adherence to offloading and facilitating personalised care. This paper introduces the concept of gamification and emotive visual indicators as novel methods to enhance patient engagement. It further discusses the transformative role of digital health technologies in the modern era.

Conclusions:

The integration of technology with footwear and offloading devices offers unparallelled opportunities for improving diabetic foot disease management not only through better offloading but also through improved adherence to offloading. These advancements allow healthcare providers to personalise treatment plans more effectively, thereby promising a major improvement in patient outcomes in diabetic foot ulcer healing and prevention.

1 |. INTRODUCTION

Offloading and adherence to offloading play a critical role in the prevention and treatment of diabetic foot ulcers (DFUs). Offloading, which involves alleviating the pressure on the affected foot, is a cornerstone aspect in DFU prevention and management and minimises the risk of recurrence.^1,2 International guidelines underscore the significance of offloading high plantar pressure from DFUs and high peak pressure regions as a key healing and prevention strategy.^3,4 But a good offloading device or shoe can only be effective when worn by the patient and hence adherence is also a central issue.

Non-removable offloading devices are the gold standard for treating DFUs due to their proven efficacy.^1,3,5 However, their adoption in clinical settings is hindered by the complexity of application and patients’ unwillingness to wear bulky devices, particularly when offloading isn’t required, such as during weightless activities or while showering.^6–9 Removable offloading devices such as knee-high walkers are common alternatives that offer similar pressure reductions.^5,10 Despite this, their healing efficacy is lower, primarily due to poor patient adherence.^1,3,5,11,12 As a result, adherence to removable devices has become a highlighted area for future research in recent international guidelines.³

After ulcer healing, for the prevention of recurrence, appropriately offloading footwear is recommended in international guidelines.⁴ Largely by definition, such footwear is removable, and adherence to treatment is always an aspect of attention in these high-risk patients. Studies have shown that custom-made footwear can be effective in reducing peak pressure at high-risk regions in the foot (where an ulcer just healed), but at the same time that adherence is low and of great concern regarding the prevention of foot ulcers in high-risk people with diabetes.^13,14 Also, in this area of prevention, international guidelines identify this topic of adherence to footwear as an area of significant future research interest.⁴

The fact that many patients do not wear their offloading device or prescribed footwear as recommended may be related to demographic, psycho-social, environmental, contextual and device or shoe-related factors. Risk-factor studies have shown that factors like diabetes history, body mass index, footwear appearance, being indoors, patient expectations towards efficacy, and postural issues influence adherence rates, although the explained variance is still not very high and 25% at maximum.^11,15–22 Nevertheless, these factors should be considered and where modifiable targeted in assessing treatment adherence and determining the treatment plan to improve adherence.

Both offloading and treatment adherence are among the most important topics in contemporary diabetic foot care. This was acknowledged during the latest International Symposium on the Diabetic Foot (ISDF) held from 10 to 13 May 2023 in the Hague in the Netherlands. The authors of this paper gave invited lectures at ISDF in which offloading and treatment adherence, and technology to measure and help improve it, was a central theme and discussed from different angles within a multifaceted approach, either (a) footwear-related, (b) using remote-monitoring for patient feedback and behavioural change, or (c) an integrated approach using smart offloading systems. This paper addresses the topics of offloading and adherence from these different perspectives after first discussing the measurement of offloading adherence and aims to provide solutions to improving offloading and adherence in order to help provide better care for people with diabetic foot disease.

2 |. MEASURING ADHERENCE TO OFFLOADING

Objective measures for evaluating adherence to offloading treatment in patients with or at risk of DFUs are advocated by various guidelines.^1,3,5 These measures can encompass wearable activity monitors to gauge the extent of adherence to total weight-bearing activity^1,16,23,24 or temperature monitors to calculate the adherence level over the total treatment time.²⁵ Nevertheless, hurdles such as the cost of monitors,²⁶ privacy concerns,^16,26,27 perceived benefit,¹⁶ perceived ease of use,^11,12,20 and limited battery life for extended use^24,28 deter their adoption. For these reasons, self-reported adherence, being quick, cost-effective, and easy to implement, is more extensively utilised in clinical practice and research.²⁹ Despite its convenience, self-reported adherence measures have proven to be unreliable when compared to objective measures, as seen in the use of footwear or offloading devices in people with diabetic foot disease and analogous treatments such as brace treatments for scoliosis.^29–31 Recent research has shown a significant discrepancy between patient self-reported and objectively measured adherence, indicating an overestimation of the former by approximately 2.6 times.²⁹ For these reasons, we advocate the use of objective quantitative methods for the measurement of adherence in people with diabetes at risk of or having a DFU and requiring offloading treatment to prevent or heal the DFU.

3 |. A MULTIFACETED APPROACH TO IMPROVING OFFLOADING ADHERENCE

Boosting adherence to offloading for treating or preventing DFUs necessitates a multi-faceted approach considering educational interventions, personalised offloading, remote monitoring, and digital technological innovations. These are listed below with short descriptions added. Subsequently, three examples are provided of either evidence-based or integrated solutions for boosting adherence to offloading in people at risk of or with a DFU.

1. Educational Interventions: Customised educational materials, including visual aids and personal stories, may help improve patient understanding of offloading significance.³² Subsequent specific educational interventions such as motivational interviewing may hold promise in helping solve the ambiguity towards wearing an offloading intervention based on the few smaller studies that have been conducted on this intervention.^32,33 This requires more exploration and confirmation from larger prospective trials.

2. Personalised Offloading Strategies: These may consist of devices or shoes designed and used for a specific context within which the patient is active, such as the home environment or driving a car, and help improve adherence to offloading in these contexts.³⁴ An example is provided below. Advanced predictive models help craft individualised offloading plans considering lifestyle, ulcer specifics, and gait. Real-time feedback can modify daily activities and improve adherence.^35,36 Individuals suffering from frailty and compromised balance may be advised to use lighter offloading measures that minimally impact postural stability.³⁷ Also, comfortable, well-fitted devices encourage better adherence. Material innovations and patient feedback can contribute to design.^16,37

3. Artificial Intelligence (AI) and Machine Learning: The burgeoning progress in AI and machine learning technologies has enabled the conception of predictive models that can preemptively detect potential adherence challenges. Such models can identify individuals at the highest risk of non-adherence, forecast the ideal personalised intervention strategy, refine intervention messaging, timing, and frequency, and enhance patient-physician communications.^38–40 For instance, a machine learning algorithm could analyse patterns in a patient’s offloading adherence and predict any deviations from the recommended strategy. Generative AI tools and language models, such as ChatGPT, may assist in developing relevant and easily comprehensible dialogues to enhance communication between care providers and patients.⁴¹ The personalisation could account for a range of factors including psychosocial metrics, occupational profiles, geographical locations, educational backgrounds, and mobility status. Despite the potential benefits, there is currently a shortage of evidence proving AI and machine learning’s effectiveness in pinpointing individuals at high risk of non-adherence.

4. Advanced Smart Devices: Smart insole systems that monitor risk parameters for DFU can help the patient through feedback to improve adherence and better offload their feet.^36,42 An example is provided below. Innovations such as intelligent shoes and in-shoe exoskeletons can enhance comfort and efficacy.^43,44 Forinstance, intelligent shoes could be engineered to automatically modulate their cushioning and support in response to alterations in a patient’s gait or pressure distribution.⁴⁵ Functional electrical stimulation might aid in modifying gait patterns to alleviate pressure in the forefoot area.⁴⁶ The integration of an in-shoe exoskeleton could facilitate offloading while enhancing gait, thus elevating the acceptability of offloading and with that the adherence thereof.⁴⁷

5. Gamification and Incentives: The process of adherence can be made more engaging and interactive by integrating game elements or providing rewards for persistent adherence.^23,44 A well-designed mobile application could serve as an effective tool for tracking adherence. The app could offer an achievement system where patients earn badges or accumulate points for consistently observing their offloading regimen. The application could also leverage the power of instant feedback with intuitive visual indicators, such as emoticons displaying happiness or sadness, corresponding to the patient’s adherence level (Figure 1).^16,23 This approach offers immediate, understandable feedback that motivates patients to improve their adherence. Moreover, a social sharing feature can be incorporated to allow patients to share their progress with caregivers or loved ones. This creates a supportive environment that nurtures the exchange of motivating messages and positive reinforcement, thereby promoting a higher level of engagement and adherence.

6. Telehealth: Telehealth platforms enhance patient monitoring and adherence to medical regimens by facilitating remote interactions between patients and providers.^43,44 These platforms offer real-time data on adherence and health metrics, enabling quick identification of risk factors and early interventions with tailored care plans. Telehealth also overcomes geographical and timing barriers, making healthcare more accessible, especially for those in remote areas or with mobility issues.⁴⁸ This not only boosts treatment adherence but also allows for efficient healthcare resource allocation by early detection of deteriorating conditions.

FIGURE 1.

Illustrations of gamification strategies from Park et al.’s study.²³ Their proposed SmartBoot application utilises emotive visual indicators for instant feedback on patient adherence levels. These intuitive displays, ranging from happy to sad emoticons, can be viewed on both smartphones and smartwatches.

3.1 |. Personalised footwear solutions for improving offloading and adherence

The ideal shoe should effectively distribute pressure and minimise peak pressure on vulnerable areas to prevent ulceration, next to protecting against direct trauma and reducing shear forces. But patient adherence is crucial; even the best shoe is ineffective if not worn. Research shows that combining effective pressure relief with patient adherence significantly reduces the risk of recurrent foot ulcers.^14,49,50

Specific shoe designs can effectively relieve peak plantar pressure in the diabetic foot. These include rocker outsoles, custom-made insoles, and metatarsal pads and bars,.⁵¹ Recent research provides biomechanical evidence that also increased bending stiffness of the shoe outsole and a 6 mm single or multi density cover of the shoe insole can provide significant peak pressure reductions.⁵² This knowledge on the biomechanical effects of these footwear designs has been used to develop a state-of-the-art algorithm for custom-made footwear design.⁵¹ In this algorithm, specific evidence-based recommendations are provided for each of the 14 domains of foot characteristics. Where evidence was not available, recommendations were consensus-based through agreement within a panel of physicians, technicians and scientists. This algorithm is the first known footwear design protocol for the high-risk diabetic foot, which additionally includes a 10-step quantitative approach for evidence-based pressure relief. Biomechanical studies demonstrate that when applying such a protocol to footwear practice, major improvements in pressure offloading can be achieved.⁵¹ In this way, the provision of footwear has become more and more a systematic, science-based, data-driven, and clinical evidence-based approach.

Factors that are shown to or likely affect footwear adherence include proper fit (so the shoe is not the cause of the damage), user expectations, walking comfort, and gait stability.²² Process-related aspects such as quick delivery, timely replacement of the whole or parts of the shoe, design consistency for repeated prescriptions, and accessibility and affordability also likely influence adherence. As the ‘ideal’ shoe that ensures consistent wearing remains elusive, these factors warrant further investigation to help target factors that may improve adherence in people who are at risk of DFU.

Footwear adherence varies by context; studies indicate it is lowest when patients are at home, while they are more active compared to being outside the house.¹⁸ Reasons reported by users for the lower adherence include heavy weight of the shoe, difficulty in putting shoes on or taking them off, not wanting to bring outdoor dirt indoors, and having a habit to take off shoes when indoors.⁵³ These findings led to the definition of a set of requirements for shoes to be worn inside the house and subsequently the development of custom-made shoes specifically for indoor use that are designed to address these user issues. One of the requirements was that the indoor shoes need to be equivalent to the custom-made outdoor shoe in terms of its pressure relieving properties, as in many cases the shoe will replace the outdoor shoe for indoor use.⁵³ Studies on this newly developed house shoe show indeed similar pressure relief and distribution to the outdoor shoe.³⁴ Adherence to wearing custom-made footwear in people who were low on adherence significantly increased with an absolute 30% both in the short term (1 month) and the long term (12 months) after providing them with specific indoor shoes.³⁴

The above is representative of a paradigm shift in the footwear provision from a stratified to a more personalised solution in which per patient data on pressure, shoe use and physical activity are used to help create the best shoe for a given at-risk person at the right time.⁵⁴ This likely means the provision of footwear for outdoor use, and a separate pair specifically for indoor use, as the combination increases footwear adherence to a substantial degree. Such data should be extended with data on patient preferences, walking comfort, gait stability, and shoe fit to further personalise footwear provision and help increase adherence and genuinely develop shoe provision towards what can be considered the best shoe for the at-risk person with diabetes. Several trials and projects are underway that have these goals in mind (DIASSIST trial registry NCT05236660 and DIALECT European program, https://dialect-diabeticfoot.eu).

3.2 |. Remote monitoring of pressure for DFU risk using smart insole systems

While high foot pressure is well acknowledged as one of the major risk factors for the development of DFU,^13,55 measuring plantar pressure outside the laboratory has been challenging until the recent advent of ‘smart insoles’. A few small-scale, laboratory-based studies have shown efficacy for the concept of using pressure feedback in people with diabetic peripheral neuropathy to help modify foot loading and plantar pressures, with the aim of reducing DFU risk.⁵⁵ Most studies have used visual guides shown to participants providing pressure feedback to try to reduce high foot pressure during walking. These studies have been laboratory-based and focused on pressure data relating to one specific high-risk area of the foot only.^35,56,57

A ‘real-world’ prospective study examined ‘high-risk’ patients’ adherence to daily use of a smart insole system providing continuous daily monitoring and alert-based feedback of foot pressures when plantar pressure thresholds have been exceeded.³⁶ High pressure feedback from the smart insoles worn in patients’ footwear during daily activities with guidance to offload pressure from the affected region of the foot was displayed to patients via a smartwatch. Over a 3-month period, patients receiving at least one high pressure alert every 2 hours were more adherent to offloading high pressures compared to patients who received fewer pressure alerts.³⁶ This real-world remote pressure monitoring study supports the concept that relatively frequent and timely pressure alerts encourage better offloading adherence compared to less frequent notifications. More frequent high-pressure alerts also led patients to wear their smart insoles for longer (average 8 h per day) compared with patients receiving fewer alerts (3.6 h per day).

A proof-of-concept randomised control ‘real-world’ trial has recently shown how continuous daily monitoring and feedback of foot pressures, using the same smart insole system used by Najafi et al.,³⁶ can reduce DFU risk over an 18-month follow-up in patients at high-risk for DFU.⁵⁸ This study recruited 90 participants with diabetic neuropathy and previous DFU, with participants randomly assigned to control (smart insole and watch but no pressure feedback) and intervention (smart insole, smart watch and high-pressure feedback) groups. Patients in the intervention group received high-pressure feedback and alerts, with the affected area displayed on a smartwatch (controls did not receive any pressure feedback). Upon high pressure notification, patients offloaded the foot and reduced pressure to the affected region. Over the 18-month follow-up period, the intervention group experienced fewer bouts of high pressure compared to controls.⁴² This decrease was the anticipated mechanism underlying the 71% reduction in the incidence of DFU in the intervention group, as observed over the same 18-month study period, relative to the control group.⁵⁸ In patients showing better adherence and wearing the smart insoles more often, the risk of DFU incidence was even reduced by 86%. It should be acknowledged that this was a relatively small-scale study (n = 90), with relatively high initial dropout. Nevertheless, this proof-of-concept trial shows the potential for smart insole systems to help ‘replace’ the natural feedback lost due to diabetic peripheral neuropathy and enable diabetes patients to better adhere to offloading treatment and self-monitor to help reduce DFU risk.

3.3 |. Integration of approaches with a focus on digital health systems: The SmartBoot

We present a practical example where some of the combinations of the features discussed above have been employed to enhance adherence to offloading treatment for DFU. At the 2023 ISDF, Najafi et al.⁵⁹ unveiled an innovative approach which integrates smart offloading and visualisation tools to monitor key parameters potentially affecting wound healing. In their study, a smart offloading device called ‘SmartBoot’ (produced by Sensoria, Figure 2) was utilised. The SmartBoot^16,23 incorporates an inertial sensor affixed to the offloading device to monitor patient adherence in real-time. This data is then transmitted via Bluetooth to a smartphone or a smartwatch. Patients receive alerts when they walk without wearing the offloading device, prompting better adherence. Moreover, the Smart-Boot adopts gamification techniques to maintain patient engagement and motivation throughout their healing process. The device streams data to a secure cloud, thereby facilitating the creation of a dashboard for the treating clinician. This clinician portal enables healthcare providers to track potential risk factors, such as poor adherence, that could negatively affect wound healing and deliver personalised education and care accordingly. Najafi et al.⁵⁹ proposed enhancing this dashboard by visualisation of a compressive and holistic view of potential factors that may impact wound healing, such as poor adherence, and to deliver personalised education and care to each patient (Figure 3). This portal presents crucial potential risk factors on a radar plot including (1) patient reported outcomes such as basic demographic data and cognitive function, (2) Sensor-driven metrics derived from a proposed smart boot (including daily step count, frailty, balance, and cadence), (3) Objective measures of adherence, and (4) Characteristics of the wound. A ′green zone is also integrated into the radar plot to simplify the interpretation of each variable and highlight parameters that could contribute to delayed wound healing. For example, an older patient might struggle more with wound healing, while a patient with a lower degree of frailty might heal more efficiently. Conversely, a higher adherence to offloading treatment is likely to lead to better wound healing outcomes.

FIGURE 2.

SmartBoot’s approach to enhancing offloading adherence.^16,23 This device integrates wearable technology with remote patient monitoring and tracking real-time adherence via an inertial sensor. The data is transmitted to a smart device, prompting patient notifications for better compliance. It employs gamification for patient engagement and streams data to a cloud for clinician monitoring and personalised care delivery.

FIGURE 3.

Najafi et al.’s⁵⁹ proposed remote patient monitoring portal visualised through a radar plot. This displays key risk factors for wound healing delays, including basic demographic and cognitive data, sensor-driven metrics from the SmartBoot (e.g., daily step count, frailty, balance, cadence), objective adherence measures, and wound characteristics. A ‘green zone’ within the plot aids in the simplified interpretation of these factors.

Figure 4 demonstrates, through two contrasting cases, how such holistic visualisation via a remote monitoring portal can be useful in pinpointing risk factors for wounds that do not heal. Figure 4A represents a typical patient with a DFU who successfully healed within a 12-week timeframe, showcasing healthy weekly wound healing speed. On the other hand, Figure 4B illustrates another patient with comparable demographic and baseline wound characteristics who failed to heal within the same timeframe due to a slower weekly wound healing speed. The main differences between these two patients lie in their adherence levels and daily step count. Such insightful visualisations of key risk factors can potentially assist healthcare providers in delivering personalised patient education and making timely decisions about alternative solutions to enhance wound outcomes. However, the efficacy of such solutions needs to be verified through future research for clinical validation.

FIGURE 4.

Comparative analysis of two patients, one who achieved successful wound healing after 12 weeks (A), and another who did not (B). The key distinguishing factors include higher daily step counts and poorer adherence in the latter patient. This visualisation aids in the rapid identification of potential risk factors, enabling healthcare providers to tailor personalised care plans and education.

4 |. CONCLUSIONS

In conclusion, this manuscript provides an overview of the approaches and latest advancements for measuring and managing offloading and footwear and offloading device adherence in people with diabetic foot disease. The emphasis is on the shoes designed for specific contexts, patient feedback systems based on remote monitoring for behaviour change, smart offloading devices and the integrated use of approaches with an emphasis on digital health solutions. It cites a range of peer-reviewed research papers and articles that support the case for specific in-house footwear, monitoring of and feedback on in-shoe and in-device pressures during everyday activities, and technological integration into healthcare systems focussing on lower extremity complications in diabetes. Each of these strategies has the aim of creating and maintaining a more effective offloading environment that facilitates more effective DFU prevention and management.

The highlighted role of gamification and emotive visual indicators to improve offloading and patient adherence, demonstrated through the SmartBoot, may be expanded to even more applications. This application not only enhances patient engagement but also allows for real-time monitoring by clinicians, exemplifying the fusion of consumer electronics and medical devices for personalised care. From radar plots for monitoring key risk factors to comparative analyses of patient outcomes based on adherence levels, actionable data is what we ultimately seek. These visualisations serve as a tool for healthcare providers to tailor personalised care plans and educational strategies and to avoid a paralysis of analysis.

Overall, technological advancement in this area can help us harness the full potential of intelligent footwear, smart insole and boot systems and other digital technologies to better offload the person at-risk of or with a DFU, improve adherence to offloading treatment, and with that combination better manage foot complications of diabetes.

DATA AVAILABILITY STATEMENT

The de-identified data needed to replicate Figure 4 will be shared upon a formal email request to Dr. Bijan Najafi (bijan.najafi@bcm.edu), assuming it will not be used for commercial purposes.