A novel shear reduction insole effect on the thermal response to walking stress, balance, and gait

The Stress of Measuring Plantar Tissue Stress in People with Diabetes-Related Foot Ulcers: Biomechanical and Feasibility Findings from Two Prospective Cohort Studies

Reducing high mechanical stress is imperative to heal diabetes-related foot ulcers. We explored the association of cumulative plantar tissue stress (CPTS) and plantar foot ulcer healing, and the feasibility of measuring CPTS, in two prospective cohort studies (Australia (AU) and The Netherlands (NL)). Both studies used multiple sensors to measure factors to determine CPTS: plantar pressures, weight-bearing activities, and adherence to offloading treatments, with thermal stress response also measured to estimate shear stress in the AU-study. The primary outcome was ulcer healing at 12 weeks. Twenty-five participants were recruited: 13 in the AU-study and 12 in the NL-study. CPTS data were complete for five participants (38%) at baseline and one (8%) during follow-up in the AU-study, and one (8%) at baseline and zero (0%) during follow-up in the NL-study. Reasons for low completion at baseline were technical issues (AU-study: 31%, NL-study: 50%), non-adherent participants (15% and 8%) or combinations (15% and 33%); and at follow-up refusal of participants (62% and 25%). These underpowered findings showed that CPTS was non-significantly lower in people who healed compared with non-healed people (457 [117; 727], 679 [312; 1327] MPa·s/day). Current feasibility of CPTS seems low, given technical challenges and non-adherence, which may reflect the burden of treating diabetes-related foot ulcers.

Application of 3D Printing Insole by Hemodynamics in Older Patients with Critical Limb Ischemia: Protocol for a Randomized Clinical Trial

Introduction

Critical limb ischemia (CLI) is a severe condition characterized by inadequate blood flow to the lower extremities, often leading to tissue damage and amputation. CLI is characterized by microcirculatory dysfunction, muscle tissue necrosis, and inflammation. Patients may suffer from the traumatic pain and the increase of plantar pressure, and foot care for patients with CLI has become the "last mile" to improve their life quality. Traditional shoe insoles often lack individual customization, failing to address the unique anatomical needs and hemodynamic characteristics of patients. The study aims to investigate the effects of this innovative intervention on improving the clinical outcomes, and quality of life in CLI patients.

Methods and Analysis

This Critical Limb Ischemia Hemodynamic Insole Study is a randomized controlled study performed to explore the effect of a 3D printing insole on foot care of CLI patients. This study recruitment began on November 1, 2021. Patients with CLI confirmed by clinical symptoms and imaging were recruited as the research objects. Participants will be randomly assigned to either the experimental group, which will receive 3D-printed insoles customized based on their hemodynamics, or the control group, which will receive traditionally manufactured insoles. Both groups were followed up for up to 24 months after surgery, including claudication distance, claudication time, pain score, rehospitalization, etc.

Trial Registration Number

ChiCTR2100051857.

Diabetic foot ulcers: Classification, risk factors and management

Diabetic foot ulceration is a devastating complication of diabetes that is associated with infection, amputation, and death, and is affecting increasing numbers of patients with diabetes mellitus. The pathogenesis of foot ulcers is complex, and different factors play major roles in different stages. The refractory nature of foot ulcer is reflected in that even after healing there is still a high recurrence rate and amputation rate, which means that management and nursing plans need to be considered carefully. The importance of establishment of measures for prevention and management of DFU has been emphasized. Therefore, a validated and appropriate DFU classification matching the progression is necessary for clinical diagnosis and management. In the first part of this review, we list several commonly used classification systems and describe their application conditions, scope, strengths, and limitations; in the second part, we briefly introduce the common risk factors for DFU, such as neuropathy, peripheral artery disease, foot deformities, diabetes complications, and obesity. Focusing on the relationship between the risk factors and DFU progression may facilitate prevention and timely management; in the last part, we emphasize the importance of preventive education, characterize several of the most frequently used management approaches, including glycemic control, exercise, offloading, and infection control, and call for taking into account and weighing the quality of life during the formulation of treatment plans. Multidisciplinary intervention and management of diabetic foot ulcers (DFUs) based on the effective and systematic combination of these three components will contribute to the prevention and treatment of DFUs, and improve their prognosis.

Digital Biomarkers of Gait and Balance in Diabetic Foot, Measurable by Wearable Inertial Measurement Units: A Mini Review

People with diabetic foot frequently exhibit gait and balance dysfunction. Recent advances in wearable inertial measurement units (IMUs) enable to assess some of the gait and balance dysfunction associated with diabetic foot (i.e., digital biomarkers of gait and balance). However, there is no review to inform digital biomarkers of gait and balance dysfunction related to diabetic foot, measurable by wearable IMUs (e.g., what gait and balance parameters can wearable IMUs collect? Are the measurements repeatable?). Accordingly, we conducted a web-based, mini review using PubMed. Our search was limited to human subjects and English-written papers published in peer-reviewed journals. We identified 20 papers in this mini review. We found preliminary evidence of digital biomarkers of gait and balance dysfunction in people with diabetic foot, such as slow gait speed, large gait variability, unstable gait initiation, and large body sway. However, due to heterogeneities in included papers in terms of study design, movement tasks, and small sample size, more studies are recommended to confirm this preliminary evidence. Additionally, based on our mini review, we recommend establishing appropriate strategies to successfully incorporate wearable-based assessment into clinical practice for diabetic foot care.

Smart Wearable Systems for the Remote Monitoring of Selected Vascular Disorders of the Lower Extremity: A Systematic Review

This systematic review aims at providing an overview of the state of the art regarding smart wearable systems (SWS) applications to monitor the status of patients suffering from vascular disorders of the lower extremity. Peer-reviewed literature has been analyzed to identify employed data collection methods, system characteristics, and functionalities, and research challenges and limitations to be addressed. The Medline (PubMed) and SCOPUS databases were considered to search for publications describing SWS for remote or continuous monitoring of patients suffering from intermittent claudication, venous ulcers, and diabetic foot ulcers. Publications were first screened based on whether they describe an SWS applicable to the three selected vascular disorders of the lower extremity, including data processing and output to users. Information extracted from publications included targeted disease, clinical parameters to be measured and wearable devices used; system outputs to the user; system characteristics, including capabilities of remote or continuous monitoring or functionalities resulting from advanced data analyses, such as coaching, recommendations, or alerts; challenges and limitations reported; and research outputs. A total of 128 publications were considered in the full-text analysis, and 54 were finally included after eligibility criteria assessment by four independent reviewers. Our results were structured and discussed according to three main topics consisting of data collection, system functionalities, and limitations and challenges.

Influence of Upper Footwear Material Properties on Foot Skin Temperature, Humidity and Perceived Comfort of Older Individuals

Studying the in-shoe microclimate of older individuals is important for enhancing their foot comfort and preventing foot diseases. However, there is a lack of scientific work that explores the thermo-physiological wear comfort of older individuals with different footwear. This study aims to examine the effects of upper footwear materials on changes and distributions in the foot skin temperature and relative humidity for older individuals. Forty older individuals are recruited to perform sitting and walking activities under four experimental conditions in a conditioning chamber. The findings indicate that footwear upper constructed of highly permeable mesh fabric with large air holes shows fewer changes in foot skin temperature (ranging from 1.3 to 3.3 °C) and relative humidity (ranging from -13.3 to 5.7%) throughout the entire foot during dynamic walking, as well as higher subjective ratings on perceived thermal comfort when compared to footwear made of synthetic leather and composite layers. The findings serve to enhance current understanding of designing footwear with optimum comfort for older adults.

A novel workflow to fabricate a patient-specific 3D printed accommodative foot orthosis with personalized latticed metamaterial

Patients with diabetes mellitus are at elevated risk for secondary complications that result in lower extremity amputations. Standard of care to prevent these complications involves prescribing custom accommodative insoles that use inefficient and outdated fabrication processes including milling and hand carving. A new thrust of custom 3D printed insoles has shown promise in producing corrective insoles but has not explored accommodative diabetic insoles. Our novel contribution is a metamaterial design application that allows the insole stiffness to vary regionally following patient-specific plantar pressure measurements. We presented a novel workflow to fabricate custom 3D printed elastomeric insoles, a testing method to evaluate the durability, shear stiffness, and compressive stiffness of insole material samples, and a case study to demonstrate how the novel 3D printed insoles performed clinically. Our 3D printed insoles results showed a matched or improved durability, a reduced shear stiffness, and a reduction in plantar pressure in clinical case study compared to standard of care insoles.

Dosing Activity and Return to Preulcer Function in Diabetes-Related Foot Ulcer Remission

Diabetes-related foot ulcers are a leading cause of global morbidity, mortality, and health-care costs. People with a history of foot ulcers have a diminished quality of life attributed to limited walking and mobility. One of the largest concerns is ulceration recurrence. Approximately 40% of patients with ulcerations will have a recurrent ulcer in the year after healing, and most occur in the first 3 months after wound healing. Hence, this period after ulceration is called "remission" due to this risk of reulceration. Promoting and fostering mobility is an integral part of everyday life and is important for maintaining good physical health and health-related quality of life for all people living with diabetes. In this short perspective, we provide recommendations on how to safely increase walking activity and facilitate appropriate off-loading and monitoring in people with a recently healed foot ulcer, foot reconstruction, or partial foot amputation. Interventions include monitored activity training, dosed out in steadily increasing increments and coupled with daily skin temperature monitoring, which can identify dangerous "hotspots" prone to recurrence. By understanding areas at risk, patients are empowered to maximize ulcer-free days and to enable an improved quality of life. This perspective outlines a unified strategy to treat patients in the remission period after ulceration and aims to provide clinicians with appropriate patient recommendations based on best available evidence and expert opinion to educate their patients to ensure a safe transition to footwear and return to activity.

Effects of offloading devices on static and dynamic balance in patients with diabetic peripheral neuropathy: A systematic review

Patients with diabetic peripheral neuropathy (DPN) usually have reduced somatosensory information and altered perception in feet and ankles. Somatosensory information acts as feedback for movement control and loss of somatosensation leads to altered plantar pressure patterns during gait and stance. Offloading devices are used to reduce peak plantar pressure and prevent diabetic foot ulcers. However, offloading devices can unfortunately have negative effects on static and dynamic balance. It is important to investigate these unwanted effects, since patient with DPN already are at high risk of falling and offloading devices could potentially increase this risk. The aim of this systematic review is to investigate the effects of plantar offloading devices used for ulcer prevention on their role in static and dynamic balance control in patients with DPN. PubMed and Embase were systematically searched using relevant search terms. After title selection, abstract selection, and full-text selection only five articles could be included for further analysis. Two articles included static balance measurements, two articles included dynamic balance measurements, and one article included both. Results suggested that static balance control is reduced when rocker bottom shoes and different insole configurations are used, however, toe-only rockers showed less evidence for reduced static balance control. There was no evidence for reduced dynamic balance control in combination with offloading devices. However, these results should be interpreted with care, since the number of studies was very small and the quality of the studies was moderate. Future research should evaluate balance in combination with different offloading devices, so that clinicians subscribing them are more aware of their potential unwanted consequences.

Harnessing Digital Health Technologies to Remotely Manage Diabetic Foot Syndrome: A Narrative Review

About 422 million people worldwide have diabetes and approximately one-third of them have a major risk factor for diabetic foot ulcers, including poor sensation in their feet from peripheral neuropathy and/or poor perfusion to their feet from peripheral artery disease. The current healthcare ecosystem, which is centered on the treatment of established foot disease, often fails to adequately control key reversible risk factors to prevent diabetic foot ulcers leading to unacceptable high foot disease amputation rate, 40% recurrence of ulcers rate in the first year, and high hospital admissions. Thus, the latest diabetic foot ulcer guidelines emphasize that a paradigm shift in research priority from siloed hospital treatments to innovative integrated community prevention is now critical to address the high diabetic foot ulcer burden. The widespread uptake and acceptance of wearable and digital health technologies provide a means to timely monitor major risk factors associated with diabetic foot ulcer, empower patients in self-care, and effectively deliver the remote monitoring and multi-disciplinary prevention needed for those at-risk people and address the health care access disadvantage that people living in remote areas. This narrative review paper summarizes some of the latest innovations in three specific areas, including technologies supporting triaging high-risk patients, technologies supporting care in place, and technologies empowering self-care. While many of these technologies are still in infancy, we anticipate that in response to the Coronavirus Disease 2019 pandemic and current unmet needs to decentralize care for people with foot disease, we will see a new wave of innovations in the area of digital health, smart wearables, telehealth technologies, and “hospital-at-home” care delivery model. These technologies will be quickly adopted at scale to improve remote management of diabetic foot ulcers, smartly triaging those who need to be seen in outpatient or inpatient clinics, and supporting acute or subacute care at home.

Footwear and insole design features for offloading the diabetic at risk foot-A systematic review and meta-analyses

The aim of this systematic review was to identify the best footwear and insole design features for offloading the plantar surface of the foot to prevent foot ulceration in people with diabetic peripheral neuropathy. We searched multiple databases for published and unpublished studies reporting offloading footwear and insoles for people with diabetic neuropathy and nonulcerated feet. Primary outcome was foot ulcer incidence; other outcome measures considered were any standardized kinetic or kinematic measure indicating loading or offloading the plantar foot. Fifty-four studies, including randomized controlled studies, cohort studies, case-series, and a case-controlled and cross-sectional study were included. Three meta-analyses were conducted and random-effects modelling found peak plantar pressure reduction of arch profile (37 kPa (MD, -37.5; 95% CI, -72.29 to -3.61; P < .03), metatarsal addition (35.96 kPa (MD, -35.96; 95% CI, -57.33 to -14.60; P < .001) and pressure informed design 75.4 kPa (MD, -75.4 kPa; 95% CI, -127.4 to -23.44 kPa; P < .004).The remaining data were presented in a narrative form due to heterogeneity. This review highlights the difficulty in differentiating the effect of different insole and footwear features in offloading the neuropathic diabetic foot. However, arch profiles, metatarsal additions and apertures are effective in reducing plantar pressure. The use of pressure analysis to enhance the effectiveness of the design of footwear and insoles, particularly through modification, is recommended.

Describing Normative Foot Temperatures in Patients With Diabetes-Related Peripheral Neuropathy

BACKGROUND

Prior research shows increased foot temperatures are predictive of diabetes-related foot complications. Our aim was to describe normative skin foot temperatures for individuals with diabetic peripheral neuropathy to better inform new technologies. We also explored for potential risk factors which correlate with changes in foot temperatures.

METHODS

We conducted a retrospective chart review of adult patients >18 years of age with diabetes mellitus and clinically diagnosed diabetic peripheral neuropathy with pedal digital thermometry performed between 2009 and 2018. A total of 58 patients met these criteria. Univariate modeling was based on covariates that may affect foot temperature including age, peripheral arterial disease, toe pressure, seasonality of measurement, smoking pack-years, caffeine use, insulin use, and calcium channel blocker use.

RESULTS

In patients with diabetic peripheral neuropathy, mean toe temperatures of 27.67°C (6.300°C), forefoot of 28.58°C (5.36°C), midfoot of 29.21°C (3.81°C), and rearfoot of 29.88°C(3.83°C) were demonstrated. A modest negative correlation between seasonality and toe and metatarsal temperatures (r = -0.38, P < .05; r = -0.43 P < .01, respectively) was demonstrated. Midfoot temperatures were modestly and positively correlated to the presence of small fiber symptoms (r = 0.33, P = .03). Positive modest correlation with rearfoot temperatures and amount of pack-year history (r = 0.30, P = .03) was seen.

CONCLUSION

Normative foot temperatures in neuropathic patients were found to be inversely associated with seasonality at the toe and metatarsal level. Smoking and pack-year history demonstrate modest correlation previously unseen in temperature analyses and warrant further exploration. Normative temperatures in neuropathic patients can better inform new technologies for the prevention of diabetic foot ulcer and Charcot neuroarthropathy.

Measuring Plantar Tissue Stress in People With Diabetic Peripheral Neuropathy: A Critical Concept in Diabetic Foot Management

Excessive stress on plantar tissue over time is one of the leading causes of diabetic foot ulcers among people with diabetic peripheral neuropathy. Plantar tissue stress (PTS) is a concept that attempts to integrate several well-known mechanical factors into one measure, including plantar pressure, shear stress, daily weight-bearing activity, and time spent in prescribed offloading interventions (adherence). Despite international diabetic foot guidelines recommending the measure of each of these individual mechanical factors in people with neuropathy, only recently has technology enabled their combined measurement to determine PTS. In this article we review the concept of PTS, the mechanical factors involved, and the findings of pivotal articles reporting measures of PTS in people with neuropathy. We also discuss key existing gaps in this field, including the lack of standards to measure and report PTS, a lack of practical solutions to measure shear stress, and the lack of PTS thresholds that may indicate benefit or detriment to people with neuropathy. To address some of these gaps, we propose recommended clinical and research standards for measuring and reporting PTS in people with neuropathy. Last, we forecast future clinical, research, and technological advancements that may use PTS to highlight the importance of this critical concept in the prevention and management of diabetic foot ulcers.

On the Cutting Edge: Wound Care for the Endovascular Specialist

Clinical outcomes in patients with critical limb ischemia (CLI) depend not only on endovascular restoration of macrovascular blood flow but also on aggressive periprocedural wound care. Education about this area of CLI therapy is essential not only to maximize the benefits of endovascular therapy but also to facilitate participation in the multidisciplinary care crucial to attaining limb salvage. In this article, we review the advances in wound care products and therapies that have granted the wound care specialist the ability to heal previously nonhealing wounds. We provide a primer on the basic science behind wound healing and the pathogenesis of ischemic wounds, familiarize the reader with methods of tissue viability assessment, and provide an overview of wound debridement techniques, dressings, hyperbaric therapy, and tissue offloading devices. Lastly, we explore emerging technology on the horizons of wound care.

An Optical-Fiber-Based Smart Textile (Smart Socks) to Manage Biomechanical Risk Factors Associated With Diabetic Foot Amputation

OBJECTIVE

This study aimed to validate a smart-textile based on fiber-optics for simultaneous measurement of plantar temperature, pressure, and joint angles in patients with diabetic peripheral neuropathy (DPN).

METHODS

After in-vitro validation in the laboratory, 33 eligible subjects with DPN were recruited (age: 58 ± 8 years, BMI: 31.5 ± 8 kg/m²) for assessing plantar pressure and temperature during habitual gait-speed in a clinical-setting. All participants were asked to walk at their habitual speed while wearing a pair of sensorized socks made from highly flexible fiber optics (SmartSox). An algorithm was designed to estimate temperature, pressure, and toe range of motion from optical wavelength generated from SmartSox. To validate the device, results from thermal stress response (TSR) using thermography and peak pressure measured by computerized pressure insoles (F-Scan) were used as gold standards.

RESULTS

In laboratory and under controlled conditions, the agreements for parameters of interest were excellent ( r > .98, P = .000), and no noticeable cross-talks between measurements of temperature, angle, and pressure were observed. During clinical data acquisition, a significant correlation was found for pressure profile under different anatomical regions of interest between SmartSox and F-Scan ( r = .67, P < .050) as well as between thermography and SmartSox ( r = .55, P < .050).

CONCLUSION

This study demonstrates the validity of an innovative smart textile for assessing simultaneously the key parameters associated with risk of foot ulcers in patients with DPN. It may empower clinicians to objectively stratify foot risk and provide timely care. Another study is warranted to validate its clinical application in preventing limb threating problems in patients with DPN.

Lace Up for Healthy Feet: The Impact of Shoe Closure on Plantar Stress Response

OBJECTIVE

This study examined the impact of shoe closure on plantar thermal stress response (TSR), which is known to be a surrogate of shear stress and skin perfusion. It is aimed to explore potential impact of shoe closure on increasing risk factors associated with plantar ulcers in people with diabetic peripheral neuropathy (DPN).

METHODS

Fifteen eligible subjects were enrolled. The left foot was used as a reference and fitted to a self-adjusted and habitual lace-tightening method by each subject. The right foot was used as a test closure and fitted into three lace closure conditions: loose, tight, and preset optimal closure (reel clutch, BOA technology). Thermal images were taken after 5 minutes of acclimatization (pre-trial) and immediately after 200 walking steps in each shoe closure condition (post-trial). TSR was calculated from the thermal images.

RESULTS

TSR was significantly higher in the test closure with loose (70.24%, P = .000) and tight (66.85%, P = .007) and lower (-206.53%, P = .000) in the preset optimal closure when compared to the reference closure. Only lace closure conditions affected TSR with no significant impact from age, BMI, and gender in our sample in a multivariable regression model.

CONCLUSION

The results from this study suggest that shoelace closure technique can have a profound effect on TSR. It therefore stands to reason that optimal lace closure may have an impact in reducing risk of plantar ulcers in people with DPN. Interestingly, results revealed that even a self-adjusted lace closure may not be necessarily optimal and a preset closure setting like reel clutch might ultimately be recommended to minimize risk. Further study is warranted to confirm or refute these interesting results.

Effects of foot and ankle devices on balance, gait and falls in adults with sensory perception loss: a systematic review

BACKGROUND

Foot and ankle devices are being developed as a method of preventing people with sensory perception loss sustaining a fall. Such devices are believed to work by reducing the likelihood of a fall by improving the balance and gait of the user.

OBJECTIVES

The objective of the review was to evaluate the effectiveness of foot and ankle devices for the prevention of falls and the improvement of balance and gait in adults with sensory perception loss.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Participants were community-dwelling adults with bilateral pathological sensory perception loss.

TYPES OF INTERVENTION(S)/PHENOMENA OF INTEREST

The current review evaluated any foot or ankle device, including but not restricted to, all types of footwear (therapeutic and retail), insoles (customized and prefabricated) and ankle-foot orthoses (AFOs).

TYPES OF STUDIES

In the absence of randomized controlled trials (RCT), the review considered experimental and epidemiological study designs, except case series, individual case reports and descriptive cross-sectional studies.

OUTCOMES

The primary outcome was number of falls. Secondary outcome measures were clinical or laboratory measures of balance or gait.

SEARCH STRATEGY

A search for published and unpublished literature from inception to March 2015 written in the English language was conducted across a number of major electronic databases. A three-step search strategy was developed using MeSH terminology and keywords to ensure all that relevant materials are captured.

METHODOLOGICAL QUALITY

Methodological quality of included studies was assessed by two reviewers, who appraised each study independently, using standardized Joanna Briggs Institute (JBI) critical appraisal tools.

DATA EXTRACTION

Quantitative data were extracted from the studies that were identified as meeting the criteria for methodological quality using the standardized JBI data extraction tools.

DATA SYNTHESIS

Due to the heterogeneity of populations, interventions and outcome measures, meta-analyses were not possible and results are presented in narrative form.

RESULTS

Nine trials (from 10 papers) involving 238 participants, (14 with multiple sclerosis and 16 with idiopathic peripheral neuropathy, 150 with diabetic neuropathy) and 58 controls were included in the review. No study reported falls as an outcome measure. The results of the included studies found that in people with sensory perception loss, postural sway improved with vibrating insoles and AFO, altering the softness and texture of the top cover had no effect on postural sway, wearing footwear over long distances or AFOs improved step-to-step consistency, and no foot and ankle device was reported to have a negative effect on the balance or gait of people with sensory perception loss. The methodological quality of the included studies was poor. No study used a randomized controlled trial (RCT) methodology. No study incorporated a follow-up period or tested the intervention within the context of the intended clinical environment.

CONCLUSION

There is limited evidence to suggest that footwear and insole devices can artificially alter postural stability and may reduce the step-to-step variability in adults with sensory perception loss. Varying the material properties of an insole does not notably affect static balance or gait.