A comparison of customised and prefabricated insoles to reduce risk factors for neuropathic diabetic foot ulceration: a participant-blinded randomised controlled trial

In-shoe plantar pressure measurement technologies for the diabetic foot: A systematic review

Introduction

Loss of cutaneous protective sensation and high plantar pressures increase the risk for diabetic foot patients. Trauma and ulceration are imminent threats, making assessment and monitoring essential. This systematic review aims to identify systems and technologies for measuring in-shoe plantar pressures, focusing on the at-risk diabetic foot population.

Methods

A systematic search was conducted across four electronic databases (Scopus, Web of Science, PubMed, Oxford Journals) using PRISMA methodology, covering articles published in English from 1979 to 2024. Only studies addressing systems or sensors exclusively measuring plantar pressures inside the shoe were included.

Results

A total of 87 studies using commercially available devices and 45 articles proposing new systems or sensors were reviewed. The prevailing market offerings consist mainly of instrumented insoles. Emerging technologies under development often feature configurations with four, six or eight resistive sensors strategically placed within removable insoles. Despite some variability due to the inherent heterogeneity of human gait, these devices assess plantar pressure, although they present significant differences between them in measurement results. Individuals with diabetic foot conditions appears exhibit elevated plantar pressures, with reported peak pressures reaching approximately 1000 kPa. The results also showed significant differences between the diabetic and non-diabetic groups.

Conclusion

Instrumented insoles, particularly those incorporating resistive sensor technology, dominate the field. Systems employing eight sensors at critical locations represent a pragmatic approach, although market options extend to systems with up to 960 sensors. Differences between devices can be a critical factor in measurement and highlights the importance of individualized patient assessment using consistent measurement devices.

Choice of Piezoelectric Element over Accelerometer for an Energy-Autonomous Shoe-Based System

Shoe-based wearable sensor systems are a growing research area in health monitoring, disease diagnosis, rehabilitation, and sports training. These systems-equipped with one or more sensors, either of the same or different types-capture information related to foot movement or pressure maps beneath the foot. This captured information offers an overview of the subject's overall movement, known as the human gait. Beyond sensing, these systems also provide a platform for hosting ambient energy harvesters. They hold the potential to harvest energy from foot movements and operate related low-power devices sustainably. This article proposes two types of strategies (Strategy 1 and Strategy 2) for an energy-autonomous shoe-based system. Strategy 1 uses an accelerometer as a sensor for gait acquisition, which reflects the classical choice. Strategy 2 uses a piezoelectric element for the same, which opens up a new perspective in its implementation. In both strategies, the piezoelectric elements are used to harvest energy from foot activities and operate the system. The article presents a fair comparison between both strategies in terms of power consumption, accuracy, and the extent to which piezoelectric energy harvesters can contribute to overall power management. Moreover, Strategy 2, which uses piezoelectric elements for simultaneous sensing and energy harvesting, is a power-optimized method for an energy-autonomous shoe system.

Perceptions of protective shoes and recommendations from patients with diabetic foot ulcers

Development of diabetic foot can cause serious harm to a patient's body and pose a heavy burden on family members and society. Protective shoes are of great significance to preventing diabetic foot. The aim of the current study was to understand patients' views and suggestions concerning the selection and promotion of protective shoes for diabetics in order to explore existing obstacles and to provide a reference for improving relevant public health care policies and clinical decision-making for patients with diabetic foot ulcers (DFUs). A total of 10 patients with DFUs were recruited. All participants completed a one-hour semi-structured interview, and results reflected the participants' choice of footwear, the patients' perceptions and acceptance of protective footwear, and factors influencing those processes. The use and promotion of protective shoes in China requires greater support, including improved medical insurance policies, promotion of multidisciplinary cooperation between medicine and industry in clinical practice, and better health education.

Intelligent plantar pressure offloading for the prevention of diabetic foot ulcers and amputations

The high prevalence of lower extremity ulceration and amputation in people with diabetes is strongly linked to difficulties in achieving and maintaining a reduction of high plantar pressures (PPs) which remains an important risk factor. The effectiveness of current offloading footwear is opposed in part by poor patient adherence to these interventions which have an impact on everyday living activities of patients. Moreover, the offloading devices currently available utilize primarily passive techniques, whereas PP distribution is a dynamically changing process with frequent shifts of high PP areas under different areas of the foot. Thus, there is a need for pressure offloading footwear capable of regularly and autonomously adapting to PPs of people with diabetes. The aim of this article is to summarize the concepts of intelligent pressure offloading footwear under development which will regulate PPs in people with diabetes to prevent and treat diabetic foot ulcers. Our team is creating this intelligent footwear with an auto-contouring insole which will continuously read PPs and adapt its shape in the forefoot and heel regions to redistribute high PP areas. The PP-redistribution process is to be performed consistently while the footwear is being worn. To improve adherence, the footwear is designed to resemble a conventional shoe worn by patients in everyday life. Preliminary pressure offloading and user perceptions assessments in people without and with diabetes, respectively, exhibit encouraging results for the future directions of the footwear. Overall, this intelligent footwear is designed to prevent and treat diabetic foot ulcers while enhancing patient usability for the ultimate prevention of lower limb amputations.

Insoles to ease plantar pressure in people with diabetes and peripheral neuropathy: a feasibility randomised controlled trial with an embedded qualitative study

BACKGROUND

Therapeutic footwear and insoles are preventative strategies to reduce elevated plantar pressures associated with diabetic foot ulcer risk. An insole intervention appropriate for chairside delivery optimising plantar foot pressure reduction in people with diabetes has been developed.

AIM

To explore the feasibility and acceptability of testing an optimised insole compared with an active control insole to reduce plantar pressures for people with diabetic peripheral neuropathy.

METHODS

A double-blinded multi-centre feasibility RCT with an embedded qualitative study. Participants were randomised to either an optimised insole group (intervention) or a standard cushioned insole group (active control). Participants were assessed at baseline, 3, 6, and 12 months with clinical outcomes of foot ulceration and mean peak plantar pressure (MPPP) reduction. An embedded qualitative study involved semi-structured interviews with 12 study participants and three podiatrists to explore their experiences of the intervention and trial procedures. Data were analysed using descriptive statistics (quantitative data) and thematic analysis (qualitative data).

RESULTS

Screened were142 patients from which 61 were recruited; 30 participants were randomised to the intervention group and 31 to the active control group. Forty-two participants completed the study. At 12 months, 69% of the patient-reported questionnaires were returned and 68% of the clinical outcomes were collected. There were 17 incidences of foot ulceration occurring in 7/31 of the active control group and 10/30 in the intervention group. Mean difference in MPPP between the intervention and active control groups for all regions-of-interest combined favoured the intervention. Thematic analysis revealed three themes; accepting the study, behaviour and support during study procedures, and impact from study participation.

CONCLUSION

The results of the feasibility RCT suggest that the optimised insole holds promise as an intervention, and that a full RCT to evaluate the clinical and cost-effectiveness of this intervention is feasible and warranted for people with diabetic peripheral neuropathy.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number: ISRCTN16011830 . Registered 9th October 2017.

Effects of three-dimensional image based insole for healthy volunteers: a pilot clinical trial

Insoles are used to treat various foot diseases, including plantar foot, diabetic foot ulcers, and refractory plantar fasciitis. In this study, we investigated the effects of 3-dimensional image-based (3-D) insole in healthy volunteers with no foot diseases. Additionally, the comfort of the 3-D insole was compared with that of a custom-molded insole. A single-center, randomized, open clinical trial was conducted to address the effectiveness of insole use in a healthy population with no foot or knee disease. Two types of arch support insoles were evaluated for their effectiveness: a 3-D insole and a custom-molded insole. Fifty Korean volunteers participated in the study and were randomly allocated into the "3-D insole" (n = 40) or "custom-molding insole" (n = 10) groups. All subjects wore 3-D insoles or custom-molded insoles for 2 weeks. The sense of wearing shoes (Visual Analog Scale [VAS] and score) and fatigue of the foot were used to assess the insole effects at the end of the 2-week study period. The 3-D insole groups showed significantly improved sense of wearing shoes (VAS, p = 0.0001; score, p = 0.0002) and foot fatigue (p = 0.0005) throughout the study period. Although the number of subjects was different, the custom-molding insole group showed no significant changes in the sense of wearing shoes (VAS, 0.1188; score, p = 0.1483). Foot fatigue in the 3-D insole group improved significantly (p = 0.0005), which shows that a 3-D insole might have favorable effects on foot health in a healthy population.

Trial Registration

Clinical Research Information Service Identifier: KCT0008100.

Footwear and insole design parameters to prevent occurrence and recurrence of neuropathic plantar forefoot ulcers in patients with diabetes: a series of N-of-1 trial study protocol

BACKGROUND

Foot complications occur in conjunction with poorly controlled diabetes. Plantar forefoot ulceration contributes to partial amputation in unstable diabetics, and the risk increases with concomitant neuropathy. Reducing peak plantar forefoot pressure reduces ulcer occurrence and recurrence. Footwear and insoles are used to offload the neuropathic foot, but the success of offloading is dependent on patient adherence. This study aims to determine which design and modification features of footwear and insoles improve forefoot plantar pressure offloading and adherence in people with diabetes and neuropathy.

METHODS

This study, involving a series of N-of-1 trials, included 21 participants who had a history of neuropathic plantar forefoot ulcers. Participants were recruited from two public hospitals and one private podiatry clinic in Sydney, New South Wales, Australia. This trial is non-randomised and unblinded. Participants will be recruited from three sites, including two high-risk foot services and a private podiatry clinic in Sydney, Australia. Mobilemat™ and F-Scan® plantar pressure mapping systems by TekScan® (Boston, USA) will be used to measure barefoot and in-shoe plantar pressures. Participants' self-reports will be used to quantify the wearing period over a certain period of between 2 and 4 weeks during the trial. Participant preference toward footwear, insole design and quality-of-life-related information will be collected and analysed. The descriptive and inferential statistical analyses will be performed using IBM SPSS Statistics (version 27). And the software NVivo (version 12) will be utilised for the qualitative data analysis.

DISCUSSION

This is the first trial assessing footwear and insole interventions in people with diabetes by using a series of N-of-1 trials. Reporting self-declared wearing periods and participants' preferences on footwear style and aesthetics are the important approaches for this trial. Patient-centric device designs are the key to therapeutic outcomes, and this study is designed with that strategy in mind.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12620000699965p. Registered on June 23, 2020.

Evaluation of novel plantar pressure-based 3-dimensional printed accommodative insoles - A feasibility study

BACKGROUND

Custom insoles are commonly prescribed to patients with diabetes to redistribute plantar pressure and decrease the risk of ulceration. Advances in 3D printing have enabled the creation of 3D-printed personalized metamaterials whose properties are derived not only from the base material but also the lattice microstructures within the metamaterial. Insoles manufactured using personalized metamaterials have both patient-specific geometry and stiffnesses. However, the safety and biomechanical effect of the novel insoles have not yet been tested clinically.

METHODS

Individuals without ulcer, neuropathy, or deformity were recruited for this study. In-shoe walking plantar pressure at baseline visit was taken and sensels with pressure over 200 kPa was used to define offloading region(s). Three pairs of custom insoles (two 3D printed insoles with personalized metamaterials (Hybrid and Full) designed based on foot shape and plantar pressure mapping and one standard-of-care diabetic insole as a comparator). In-shoe plantar pressure measurements during walking were recorded in a standardized research shoe and the three insoles and compared across all four conditions.

FINDINGS

Twelve individuals were included in the final analysis. No adverse events occurred during testing. Maximum peak plantar pressure and the pressure time integral were reduced in the offloading regions in the Hybrid and Full but not in the standard-of-care compared to the research shoe.

INTERPRETATION

This feasibility study confirms our ability to manufacture the 3D printed personalized metamaterials insoles and demonstrates their ability to reduce plantar pressure. We have demonstrated the ability to modify the 3D printed design to offload certain parts of the foot using plantar pressure data and a patient-specific metamaterials in the 3D printed insole design. The advance in 3D printed technology has shown its potential to improve current care.

Offloading treatment in people with diabetic foot disease: A systematic scoping review on adherence to foot offloading

BACKGROUND AND AIMS

To identify measurement methods, proportions of adherent participants, factors affecting adherence, and concordance promoting interventions.

METHODS

A systematic scoping review was conducted by searching Medline, CINAHL, PubMed, EMBASE, and EMCARE databases.

RESULTS

Twenty-four trials were identified from 1001 citations. Only 25% of the included studies used objective methods to quantify adherence. The proportion of adherent participants (≥80% of daily steps/time) ranged from 28% to 60%. Psychosocial factors are the most common influencers of adherence. However, interventions for improving compliance are lacking.

CONCLUSION

There is a need to accurately quantify and optimize adherence to foot offloading in people with diabetes.

Foot deformation analysis with different load-bearing conditions to enhance diabetic footwear designs

In-depth analyses of foot surface measurements upon weight bearing are crucial to understand how the dorsal and plantar surfaces of the foot deform during motion to enhance the fit of footwear, which is particularly important for diabetic patients with stringent fit requirements to redistribute the plantar weight forces. This study analyzes diabetic foot deformations under 3 different weight bearing conditions (no weight bearing, half weight bearing, and 80% weight bearing) by using a novel foot scanning method that enables efficient scanning of the dorsal and plantar surfaces of the foot simultaneously. The feet of 48 patients with diabetes mellitus (DM) are scanned. With increased load on the feet, the width of the forefoot increases by 9.7%-10.4%, height of the midfoot decreases by 15.1%-18.2%, forefoot and midfoot rotate to the medial side by 16.9%-23.9% while the rearfoot rotates to the lateral side by 15.2% simultaneously, and the plantar of the foot increases contact with the floor by 11.4%-23.0%. Gender differences in foot shape are also found between males and females, males have a broader foot than females for the same foot length. Precise anthropometric information of foot changes and deformation therefore enables adequate foot protection, fit and comfort when designing footwear. This research contributes to shoe design considerations that focus on the deformation of the foot under different loads.

Plantar pressure distribution during running with a self-customized foot orthosis in a home microwave

The individualization of a custom-made foot orthosis could provide improvements in plantar loading distribution regarding a prefabricated one. However, not all runners can afford it because of its high cost. A new type of low-cost prefabricated foot orthoses with self-customization could be the solution. The aim of the study was to evaluate if self-customized prefabricated foot orthoses (SCFO) could improve plantar pressure distribution with respect to generic prefabricated ones without customization, during the intense prolonged running. Thirty healthy recreational runners performed two tests of 30 min running on a treadmill, each one with a foot orthosis condition, on different days. Mean peak pressure, pressure-time integral, relative pressure and stance time were measured at the beginning and at the end of the tests. Plantar pressure data were analyzed in nine foot regions. Two-way repeated-measures ANOVAs were performed. SCFO reduced relative pressure in metatarsals (P < 0.005) and lateral heel (P = 0.004), thanks to a greater involvement of arch area in mean peak pressure (medial: P = 0.006 and lateral: P = 0.019) and relative pressure (P < 0.001). In general, prolonged run increased pressures in forefoot, in both foot orthosis, but with lower values in metatarsals with SCFO (P < 0.022), which also helped reduce relative pressure in midfoot (P = 0.007) and medial heel (P = 0.035). Stance time was not modified in any case (P > 0.05). In conclusion, customization and better fit of a low-cost prefabricated foot orthosis can improve plantar pressure distribution during a prolonged run, being a good prevention mechanism for plantar overloading in healthy runners.

The Design of Individual Orthopedic Insoles for the Patients with Diabetic Foot Using Integral Curves to Describe the Plantar Over-Pressure Areas

Identification of over-pressure areas in the plantar side of the foot in patients with diabetic foot and reduction of plantar pressure play a major role in clinical practice. The use of individual orthopedic insoles is essential to reduce the over-pressure. The aim of the present study is to mark the over-pressure areas of the plantar part of the foot on a pedogram and describe them with high accuracy using a mathematical research method. The locally over-pressured areas with calluses formed due to repeated injuries were identified on the patients' pedograms. The geometric shapes of the over-pressure areas were described by means of the integral curves of the solutions to Dirichlet singular boundary differential equations. Based on the mathematical algorithm describing those curves, the computer programs were developed. The individual orthopedic insoles were produced on a computer numerical control milling machine considering the locally over-pressured areas. The ethylene vinyl acetate polymers of different degrees of hardness were used to produce the individual orthopedic insoles. For the over-pressure areas, a soft material with a hardness of 20 Shore A was used, which reduces the pressure on the plantar side of the foot and increases the contact area. A relatively hard material with a hardness of 40 Shore A was used as the main frame, which imparts the stability of shape to the insole and increases its wear life. The individual orthopedic insoles produced by means of such technology effectively reduce the pressure on the plantar side of the foot and protect the foot from mechanical damage, which is important for the treatment of the diabetic foot.

Measuring sustainability in healthcare: an analysis of two systems providing insoles to patients with diabetes

There is an increasing demand to quantify the footprints, ecological, economic and social, in terms of the effect of different interventions in healthcare. The aim of this study was to compare two systems providing patients with diabetes with insoles in terms of their ecological, economic and social footprints. Prefabricated insoles (PRI) were compared with custom-made insoles (CMI). Using a welfare-economic monetary approach, costs were estimated for (1) treatment, (2) travelling to and from the hospital in terms of both fuel and time consumed by the patients and (3) society through emissions contributing to climate change. The proportion of patients/year that could be supplied within the same budget, for each individual treatment, was calculated. The cost of the insoles was 825 SEK (PRI) and 1450 SEK (CMI), respectively. The cost, mean value/patient due to the consumption of patients' time at the department, was 754 SEK (PRI) and 1508 SEK (CMI), respectively. Emissions, in terms of CO₂ equivalent, were 13.7 (PRI) and 27.4 (CMI), respectively. Using PRI, a total of 928 patients could be provided/year compared with 500 patients if CMI are used. By using PRI, the cost/treatment was reduced by 46%. The cost of treatment dominated and the cost of time consumed by patients were also substantial. The societal cost of contributing to climate change was of low importance. By using PRI, the needs of 86% more patients could be met within the same budget. Using these methods, the contribution of healthcare systems to the 17 Sustainable Development Goals approved by the UN can be quantified.

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.

An individually moulded insole with 5-mm medial arch support reduces peak impact and loading at the heel after a one-hour treadmill run

BACKGROUND

Foot pain experienced by long-distance runners could be relieved by functional insoles which aim at evenly distributing the plantar pressure.

RESEARCH QUESTION

We hypothesised that an individually moulded insole with medial arch support would reduce the impact and loading under the heel and metatarsal regions.

METHODS

Twelve male recreational runners ran on a treadmill at 10 km/h for 1 hour with flat insoles and medial arch supported insoles. A pressure insole system (Novel Pedar, Germany) was used to obtain the peak pressure, peak force, time normalised pressure-time integrals, and the percentage of the total force-time integrals under 10 regions.

RESULTS

Medial arch supported insoles reduced the peak force under the heel (medial: -15.3%, p = 0.001; lateral: -19.2%, p = 0.037) during the initial run, and reduced peak pressure under the heel (medial: -13.3%, p = 0.005; lateral: -9.9%, p = 0.006), and peak force under the medial heel (-17.8%, p = 0.006) after the run. The percentage of the total force-time integrals under the heel was reduced (medial: -23.8%, p = 0.004; lateral: -13.6%, p = 0.022) after the run. No significant difference was found under the metatarsal regions. There is shift of load from the metatarsal regions to the medial mid-foot as indicated by the change of the percentage of total force-time integrals.

SIGNIFICANCE

Medial arch supported insoles were effective in reducing the impact and loading under the heel region in prolonged running on a treadmill.

LEVEL OF EVIDENCE

Controlled laboratory study, Level V.

Footwear and insole design features that reduce neuropathic plantar forefoot ulcer risk in people with diabetes: a systematic literature review

BACKGROUND

In people with diabetes, offloading high-risk foot regions by optimising footwear, or insoles, may prevent ulceration. This systematic review aimed to summarise and evaluate the evidence for footwear and insole features that reduce pathological plantar pressures and the occurrence of diabetic neuropathy ulceration at the plantar forefoot in people with diabetic neuropathy.

METHODS

Six electronic databases (Medline, Cinahl, Amed, Proquest, Scopus, Academic Search Premier) were searched in July 2019. The search period was from 1987 to July 2019. Articles, in English, using footwear or insoles as interventions in patients with diabetic neuropathy were reviewed. Any study design was eligible for inclusion except systematic literature reviews and case reports. Search terms were diabetic foot, physiopathology, foot deformities, neuropath*, footwear, orthoses, shoe, footwear prescription, insole, sock*, ulcer prevention, offloading, foot ulcer, plantar pressure.

RESULTS

Twenty-five studies were reviewed. The included articles used repeated measure (n = 12), case-control (n = 3), prospective cohort (n = 2), randomised crossover (n = 1), and randomised controlled trial (RCT) (n = 7) designs. This involved a total of 2063 participants. Eleven studies investigated footwear, and 14 studies investigated insoles as an intervention. Six studies investigated ulcer recurrence; no study investigated the first occurrence of ulceration. The most commonly examined outcome measures were peak plantar pressure, pressure-time integral and total contact area. Methodological quality varied. Strong evidence existed for rocker soles to reduce peak plantar pressure. Moderate evidence existed for custom insoles to offload forefoot plantar pressure. There was weak evidence that insole contact area influenced plantar pressure.

CONCLUSION

Rocker soles, custom-made insoles with metatarsal additions and a high degree of contact between the insole and foot reduce plantar pressures in a manner that may reduce ulcer occurrence. Most studies rely on reduction in plantar pressure measures as an outcome, rather than the occurrence of ulceration. There is limited evidence to inform footwear and insole interventions and prescription in this population. Further high-quality studies in this field are required.

State of the art design protocol for custom made footwear for people with diabetes and peripheral neuropathy

Supported by evidence-based guidelines, custom-made footwear is often prescribed to people with diabetes who are at risk for ulceration. However, these guidelines do not specify the footwear design features, despite available scientific evidence for these features. We aimed to develop a design protocol to support custom-made footwear prescription for people with diabetes and peripheral neuropathy. The population of interest was people with diabetes who are at moderate-to-high risk of developing a foot ulcer, for whom custom-made footwear (shoes and/or insoles) can be prescribed. A group of experts from rehabilitation medicine, orthopaedic shoe technology (pedorthics) and diabetic foot research, reviewed the scientific literature and met during 12 face-to-face meetings to develop a footwear design algorithm and evidence-based pressure-relief algorithm as parts of the protocol. Consensus was reached where evidence was not available. Fourteen domains of foot pathology in combination with loss of protective sensation were specified for the footwear design algorithm and for each domain shoe-specific and insole (orthosis)-specific features were defined. Most insole-related features and some shoe-related features were evidence based, whereas most shoe-related features were consensus based. The pressure-relief algorithm was evidence based using recent footwear trial data and specifically targeted patients with a healed plantar foot ulcer. These footwear design and pressure-relief algorithms are the first of their kind and should facilitate more uniform decision making in the prescription and manufacturing of adequate shoes for moderate-to-high-risk patients, reducing variation in footwear provision and improving clinical outcome in the prevention of diabetic foot ulcers.

Treatment of modifiable risk factors for foot ulceration in persons with diabetes: a systematic review

BACKGROUND

Prevention of diabetic foot ulcers is important. Preventative treatment mostly targets and aims to improve modifiable risk factors of foot ulceration. While effectiveness of interventions in ulcer prevention has been systematically reviewed, their effectiveness in improving modifiable risk factors is unknown.

METHODS

The available medical scientific literature in PubMed, Excerpta Medica Database, and the Cochrane database was searched for original research studies on six interventions to treat modifiable risk factors for diabetic foot ulceration (ie, education for patients; education for professionals; self-management; pre-ulcer treatment; orthotic interventions; and foot- and mobility-related exercises). We assessed interventions for eight outcomes (ie, patients' knowledge; treatment adherence; professionals' knowledge; pre-ulcers; mechanical stress; neuropathy symptoms; foot/ankle joint mobility; and foot function). Both controlled and noncontrolled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers and extracted and presented in evidence and risk of bias tables.

RESULTS

We included 72 publications (26 with a controlled study design and 46 noncontrolled). We found that structured education may improve foot self-care behaviour of patients, yearly foot examinations, and foot disease knowledge of health care professionals. Callus removal reduces peak plantar pressure. Custom-made therapeutic footwear can be effective in reducing plantar pressure and may reduce callus. Foot- and mobility-related exercises may improve neuropathy symptoms and foot and ankle joint range of motion, while they do not seem to reduce peak plantar pressure; evidence for their effect on foot strength is conflicting.

CONCLUSIONS

Structured education for patients and health care professionals, callus removal, custom-made therapeutic footwear, and foot- and mobility-related exercises may be beneficial for improving modifiable risk factors for foot ulceration. However, we generally found low quality of evidence for interventions targeting modifiable risk factors for ulceration in persons with diabetes, with frequently inconsistent or limited results available per intervention and outcome.

Effects of Preconditioning Local Vibrations on Subsequent Plantar Skin Blood Flow Response to Walking

Weight-bearing exercise such as walking may increase risk of foot ulcers in people with diabetes mellitus (DM) because of plantar ischemia due to repetitive, high plantar pressure. Applications of local vibrations on plantar tissues as a preconditioning intervention before walking may reduce plantar tissue ischemia during walking. The objective of this study was to explore whether preconditioning local vibrations reduce reactive hyperemia after walking. A double-blind, repeated-measures, and crossover design was tested in 10 healthy participants without DM. The protocol included 10-minute baseline, 10-minute local vibrations (100 Hz or sham), 10-minute walking, and 10-minute recovery periods. The order of local vibrations was randomly assigned. Skin blood flow (SBF) was measured over the first metatarsal head during baseline and recovery periods. SBF responses were characterized as peak SBF, total SBF, and recovery time of reactive hyperemia. SBF was expressed as a ratio of recovery to baseline SBF to quantify the changes. Peak SBF in the vibration protocol (6.98 ± 0.87) was significantly lower than the sham control (9.26 ± 1.34, P < .01). Total SBF in the vibration protocol ([33.32 ± 7.98] × 103) was significantly lower than the sham control ([48.09 ± 8.9] × 103, P < .05). The recovery time in the vibration protocol (166.08 ± 32.71 seconds) was not significantly different from the sham control (223.53 ± 38.85 seconds, P = .1). Local vibrations at 100 Hz could reduce walking-induced hyperemic response on the first metatarsal head. Our finding indicates that preconditioning local vibrations could be a potential preventive intervention for people at risk for foot ulcers.

The insole materials influence the plantar pressure distributions in diabetic foot with neuropathy during different walking activities

BACKGROUND

Abnormal peak plantar pressure in neuropathic diabetic foot during walking activities is well managed through the use of appropriate design and material selection for the fabrication of custom made insoles (CMI). The redistribution of plantar pressure is possible by selecting an appropriate material for the fabrication of CMI. The walking activities may alter the plantar pressure distribution; which may differ while using CMI with different materials.

OBJECTIVE

The objective of the study was to evaluate the effectiveness of CMI's materials on plantar pressure distribution during different walking activities, in diabetic feet with neuropathy.

METHODS

The study was conducted on sixteen diabetic neuropathic subjects. The subjects were provided with two types of CMI; CMI-A (Plastazote® and microcellular rubber) and CMI-B (Multifoam, Plastazote® and microcellular rubber). Maximum peak plantar pressure and plantar pressure distribution were determined by Pedar-X® sensor insole during level walking, ramp walking and stair walking.

RESULTS

The CMI-B lessened the maximum peak plantar pressure from the forefoot throughout the walking activities compared to CMI-A. The contact area was observed as lower using CMI-A compared to CMI-B, while performing walking activities.

CONCLUSION

CMI-B, with multifoam as an additional top layer, provided more effective peak plantar pressure reduction at forefoot and it had better plantar pressure distribution compared to CMI-A during level walking and ramp ascending in diabetic foot with neuropathy.

Validation of a novel Kinect-based device for 3D scanning of the foot plantar surface in weight-bearing

Background

Advancements in additive manufacturing, along with new 3D scanning tools, are increasingly fulfilling the technological need for custom devices in personalized medicine. In podiatry and in the footwear industry, custom orthotic and footwear solutions are often required to address foot pathologies or morphological alterations which cannot be managed with standard devices. While laser scanners are the current gold-standard for 3D digitization of the foot shape, their costs limit their applications and diffusion, therefore traditional operator-dependent casting methods are still in use. The aim of this study was to design and validate a novel 3D foot scanner based on the Microsoft Kinect sensor, allowing a 3D scan of the plantar shape of the foot to be acquired in weight-bearing.

Methods

The accuracy and repeatability of the prototypal foot scanner were investigated in a population of 14 asymptomatic healthy subjects, with no history of foot or lower limb injuries. The accuracy was estimated by comparing the Kinect foot scans with those obtained with a high-resolution laser scanner used as reference. The repeatability was assessed by comparing scans of the same foot acquired in different sessions.

Results

The inter-subject average Root Mean Square Error (RMSE) of the Kinect scans was lower than 3 mm for the whole plantar surface, and lower than 1.6 mm for the arch region alone, both in left and right feet. The repeatability, quantified as the average RMSE of pairwise comparisons between sessions, was 1.2 ± 0.4 mm.

Conclusions

The present Kinect-based 3D foot scanner showed optimal intra-operator repeatability and its accuracy appears adequate to obtain 3D scans of the foot plantar surface suitable for different clinical applications. This device could represent a valid low-cost alternative to expensive laser-based scanners and could be used for automatic foot measurements, supporting the design of custom insoles and footwear.

Textured shoe insoles to improve balance performance in adults with diabetic peripheral neuropathy: study protocol for a randomised controlled trial

INTRODUCTION

Peripheral neuropathy is a major risk factor for falls in adults with diabetes. Innovative footwear devices which artificially manipulate the sensory environment at the feet, such as textured shoe insoles, are emerging as an attractive option to mitigate balance and walking problems in neuropathic populations. This study aims to explore whether wearing textured insoles for 4 weeks alters balance performance in adults with diabetic peripheral neuropathy.

METHODS AND ANALYSIS

A prospective, single-blinded randomised controlled trial with parallel groups will be conducted on 70 adults with diabetic peripheral neuropathy. Adults with a diagnosis of peripheral neuropathy (secondary to type 2 diabetes), aged ≥18 years, ambulant over 20 m (with/without an assistive device), will be recruited. Participants will be randomised to receive a textured insole (n=35) or smooth insole (n=35), to be worn for 4 weeks. During baseline and post intervention assessments, standing balance (foam/firm surface; eyes open/closed) and walking tasks will be completed barefoot, wearing standard shoes only, and two different insoles (smooth, textured). The primary outcome measure will be centre of pressure (CoP) velocity, with higher values indicating poorer balance. Secondary outcome measures include walking quality (gait velocity, base of support, stride length and double-limb support time), physical activity levels, foot sensation (light-touch pressure, vibration) and proprioception (ankle joint position sense), and other balance parameters (CoP path length, anteroposterior and mediolateral excursion). Patient-reported outcomes will be completed evaluating foot health, frequency of falls and fear of falling. Data will be analysed using a repeated measures mixed models approach (including covariates) to establish any differences between-groups, for all outcome measures, over the intervention period.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the institutional Human Research Ethics Committee (#2017000098). Findings will be disseminated at national and international conferences, through peer-reviewed journals, workshops and social media.

TRIAL REGISTRATION NUMBER

ACTRN12617000543381; Pre-results.

An integrative review of therapeutic footwear for neuropathic foot due to diabetes mellitus

BACKGROUND

Therapeutic footwear is built on a model of patient's foot, for people with diabetes suffering with neuropathy. Can the footwear helps to improve plantar pressure in neuropathic foot? This study focussed on available data on therapeutic footwear as an intervention for improving and offloading plantar pressure in neuropathic diabetic foot.

METHODS

Relevant scientific literature in PubMed, Medline and Google Scholar published between 2000 and 2017 were searched. The keywords searched were therapeutic footwear, plantar pressure, neuropathic foot, rocker sole, ulcer healing and offloading of plantar pressure. Articles on randomized controlled trials, observational, cohort, feasibility and factorial studies were reviewed.

RESULTS

One hundred and twenty five (125) articles were identified. The article comprised of 6 randomized controlled trials, 2 observational, 1 cohort, 1 feasibility and 1 factorial study met the inclusion criteria and were critiqued with a total enrolment of 1380 study subjects.

CONCLUSIONS

The review of the collated literature demonstrated that, therapeutic footwear can improve the healing of neuropathic diabetic foot ulcer by redistributing plantar pressure. However, the efficacy of therapeutic footwear requires the inclusion of technical features that should not be compromised from the design to the production of the footwear.

The Classification of Minor Gait Alterations Using Wearable Sensors and Deep Learning

OBJECTIVE

This paper describes how non-invasive wearable sensors can be used in combination with deep learning to classify artificially induced gait alterations without the requirement for a medical professional or gait analyst to be present. This approach is motivated by the goal of diagnosing gait abnormalities on a symptom-by-symptom basis, irrespective of other neuromuscular movement disorders the patients may be affected by. This could lead to improvements in treatment and offer a greater insight into movement disorders.

METHODS

In-shoe pressure was measured for 12 able-bodied participants, each subject to eight artificially induced gait alterations, achieved by modifying the underside of the shoe. The data were recorded at 100 Hz over 2520 data channels and were analyzed using the deep learning architecture and the long term short term memory networks. Additionally, the rationale for the decision-making process of these networks was investigated.

CONCLUSION

Long term short term memory networks are applicable to the classification of the gait function. The classifications can be made using only 2 s of sparse data (82.0% accuracy over 96 000 instances of test data) from participants who were not a part of the training set.

SIGNIFICANCE

This paper provides potential for the gait function to be accurately classified using non-invasive techniques, and at more regular intervals, outside of a clinical setting, without the need for healthcare professionals to be present.

A randomised controlled trial and cost-consequence analysis of traditional and digital foot orthoses supply chains in a National Health Service setting: application to feet at risk of diabetic plantar ulceration

BACKGROUND

Diabetic foot ulceration is a considerable cost to the NHS and foot orthotic provision is a core strategy for the management of the people with diabetes and a moderate to high risk of foot ulceration. The traditional process to produce a custom-made foot orthotic device is to use manual casting of foot shape and physical moulding of orthoses materials. Parts of this process can be undertaken using digital tools rather than manual processes with potential advantages. The aim of this trial was to provide the first comparison of a traditional orthoses supply chain to a digital supply chain over a 6 month period. The trial used plantar pressure, health status, and health service time and cost data to compare the two supply chains.

METHODS

Fifty-seven participants with diabetes were randomly allocated to each supply chain. Plantar pressure data and health status (EQ5D, ICECAP) was assessed at point of supply and at six-months. The costs for orthoses and clinical services accessed by participants were assessed over the 6 months of the trial. Primary outcomes were: reduction in peak plantar pressure at the site of highest pressure, assessed for non-inferiority to current care. Secondary outcomes were: reduction in plantar pressure at foot regions identified as at risk (> 200 kPa), cost-consequence analysis (supply chain, clinician time, service use) and health status.

RESULTS

At point of supply pressure reduction for the digital supply chain was non-inferior to a predefined margin and superior (p < 0.1) to the traditional supply chain, but both supply chains were inferior to the margin after 6 months. Custom-made orthoses significantly reduced pressure for at risk regions compared to a flat control (traditional - 13.85%, digital - 20.52%). The digital supply chain was more expensive (+£13.17) and required more clinician time (+ 35 min). There were no significant differences in health status or service use between supply chains.

CONCLUSIONS

Custom made foot orthoses reduce pressure as expected. Given some assumptions about the cost models we used, the supply chain process adopted to produce the orthoses seems to have marginal impact on overall costs and health status.

TRIAL REGISTRATION

Retrospectively registered on ISRCTN registry (ISRCTN10978940, 04/11/2015).

A survey of foot orthoses prescription habits amongst podiatrists in the UK, Australia and New Zealand

Background

Foot orthoses are frequently used but little is known about which types are used in contemporary practice. This study aimed to explore the types of foot orthoses currently used by podiatrists and the prescription variations in a range of conditions.

Methods

A web-based, cross-sectional survey was distributed through professional bodies in the United Kingdom (UK), Australia, and New Zealand. Questions focussed on foot orthosis prescription habits in relation to 26 conditions affecting the back and lower limb.

Results

Two hundred and sixty-four podiatrists practising in 19 different countries completed the survey; the majority practised in the UK (47%, n = 124), Australia (30%, n = 79) and New Zealand (12%, n = 32). Respondents qualified between 1968 and 2016, and 147 (56%) were female. Respondents worked in different healthcare sectors and this varied between countries: 42 (34%) respondents in the UK worked solely in the public sector, compared to 3 (4%) in Australia and 2 (6%) in New Zealand. Forty-four (35%) respondents in the UK worked solely in private practice, compared to 64 (81%) in Australia and 14 (44%) in New Zealand.

UK respondents prescribed more prefabricated orthoses per week (mean 5.5 pairs) than simple insole-type devices (±2.7) and customised devices (±2.9). Similarly, respondents in New Zealand prescribed more prefabricated orthoses per week (±7.7) than simple (±1.4) and customised (±2.8) devices. In contrast, those in Australia prescribed more customised orthoses per week (±4.4) than simple (±0.8) and prefabricated (±1.9) orthoses. Differences in the types of orthoses prescribed were observed between country of practice, working sector, and the condition targeted. Generally, prefabricated orthoses were commonly prescribed for the 26 highlighted conditions in the UK and New Zealand. Australian podiatrists prescribed far fewer devices overall, but when they did prescribe, they were more likely to prescribe custom devices. Respondents in all three countries were more likely to prescribe customised orthoses for people with diabetes complicated by peripheral neuropathy than for diabetes without this complication.

Conclusions

Foot orthosis prescription habits vary between countries. Prefabricated orthoses were frequently prescribed in the UK and New Zealand, and customised orthoses in Australia. Prescriptions for people with diabetes differed depending on the presence of neuropathy, despite a lack of robust evidence supporting these decisions. This study provides new insight into contemporary practice.

Electronic supplementary material

The online version of this article (10.1186/s13047-018-0304-z) contains supplementary material, which is available to authorized users.

Examination of the Effect of Suitable Size of Shoes under the Second Metatarsal Head and Width of Shoes under the Fifth Metatarsal Head for the Prevention of Callus Formation in Healthy Young Women

Excessive pressure and shear stress while walking cause a risk of callus formation, which eventually causes foot ulcers in patients with diabetes mellitus. Callus under the second metatarsal head (MTH) has been associated with increased shear stress/pressure ratios (SPR). Callus under the fifth MTH has been associated with increased peak shear stress (PSS). The purpose of this study is to examine whether the effect of the suitable size and width of shoes prevents diabetic foot ulcers under the second and fifth MTH. We measured the pressure and shear stress by testing three kinds of sizes and two types of width of shoes. Significant difference was not observed in the SPR under the second MTH among different sizes of shoes. However, the pressure and shear stress were significantly lower when putting on shoes of fit size compared with larger sizes. The PSS under the fifth MTH was significantly smaller when putting on shoes of fit width compared with those of narrow width. Wearing shoes of fit size and width has the potential to prevent callus formation by reducing the pressure and shear stress constituting SPR under the second MTH and PSS under the fifth MTH.

Methodological considerations of investigating adherence to using offloading devices among people with diabetes

Foot ulcers are a diabetic complication associated with significant morbidity, mortality, and amputation risk. Offloading devices prevent and heal foot ulcers, but adherence to using these devices is low. The reasons for nonadherence are unclear, and study results are difficult to compare due to methodological heterogeneity. This paper explores aspects of investigating adherence to using offloading devices among people with diabetes and provides recommendations for future studies, focusing on study designs, definitions of adherence, measurement methods, and conceptual frameworks. Most studies use a cross-sectional observational study design, limiting the potential to establish the temporal sequence between predictors and adherence, rule out confounding factors, and establish causality. Studies defining adherence as the length of time the device is worn have often used self-report to measure adherence, which may be unreliable. Studies using activity monitors to measure adherence have defined adherence as the number of steps taken with the device, which excludes weight-bearing activities where no steps are taken. Conceptual frameworks are not made explicit in the current quantitative research. It is concluded that future studies should use a longitudinal design with observational studies to identify patient groups prone to nonadherence and factors that influence adherence and experimental studies to evaluate interventions to improve adherence, focusing on these patient groups and factors. Furthermore, adherence should be defined in terms of relative adherence to using offloading devices during all weight-bearing activities, and objective measurement of adherence (using accelerometers and temperature monitors) should be used whenever possible. Clearly defined conceptual frameworks should guide the choice of factors to include in the study and the analysis of their interactions. By implementing these recommendations, research could provide a stronger evidence base in the future, supporting interventions to increase adherence and thereby improve outcomes for people with diabetic foot complications.

Plantar blood flow response to accumulated pressure stimulus in diabetic people with different peak plantar pressure: a non-randomized clinical trial

The aim of this study was to investigate the plantar blood flow response to the same accumulated pressure stimulus in diabetic patients with different peak plantar pressure (PPP), which is important for assessing the risk of diabetic foot ulcer. Eleven diabetic subjects with high PPP (PPP ≥ 207 kPa) and 8 diabetic subjects with low PPP (PPP < 207 kPa) were asked to walk naturally on a treadmill so as to induce an accumulated stimulus of 73,000 kPa·s on their first metatarsal head, which was monitored with a sensorized insole. Blood perfusion (BP) in the first metatarsal head was measured before and after walking. Results showed that blood flow after applying the same walking stimulus was significantly decreased in comparison to the basal BP before walking in both high PPP and low PPP groups (p < 0.05), but no significant differences were found between the two groups in terms of BP parameters and its percentage change (p > 0.05). Moreover, BP parameters were not significantly correlated to PPP and the pressure-time integral (PTI) of the subjects' gait (p > 0.05). This indicated that, besides PPP and PTI, the accumulated mechanical stimulus should be taken into consideration when assessing the risk of diabetic patients developing foot ulcers. Graphical abstract Plantar blood flow response to a walking stimulus.

A systematic review of randomised controlled trials assessing effectiveness of prosthetic and orthotic interventions

BACKGROUND

Assistive products are items which allow older people and people with disabilities to be able to live a healthy, productive and dignified life. It has been estimated that approximately 1.5% of the world's population need a prosthesis or orthosis.

OBJECTIVE

The objective of this study was to systematically identify and review the evidence from randomized controlled trials assessing effectiveness and cost-effectiveness of prosthetic and orthotic interventions.

METHODS

Literature searches, completed in September 2015, were carried out in fourteen databases between years 1995 and 2015. The search results were independently screened by two reviewers. For the purpose of this manuscript, only randomized controlled trials which examined interventions using orthotic or prosthetic devices were selected for data extraction and synthesis.

RESULTS

A total of 342 randomised controlled trials were identified (319 English language and 23 non-English language). Only 4 of these randomised controlled trials examined prosthetic interventions and the rest examined orthotic interventions. These orthotic interventions were categorised based on the medical conditions/injuries of the participants. From these studies, this review focused on the medical condition/injuries with the highest number of randomised controlled trials (osteoarthritis, fracture, stroke, carpal tunnel syndrome, plantar fasciitis, anterior cruciate ligament, diabetic foot, rheumatoid and juvenile idiopathic arthritis, ankle sprain, cerebral palsy, lateral epicondylitis and low back pain). The included articles were assessed for risk of bias using the Cochrane Risk of Bias tool. Details of the clinical population examined, the type of orthotic/prosthetic intervention, the comparator/s and the outcome measures were extracted. Effect sizes and odds ratios were calculated for all outcome measures, where possible.

CONCLUSIONS

At present, for prosthetic and orthotic interventions, the scientific literature does not provide sufficient high quality research to allow strong conclusions on their effectiveness and cost-effectiveness.

Comparison of plantar pressure distribution in CAD-CAM and prefabricated foot orthoses in patients with flexible flatfeet

BACKGROUNDS

The effect of foot orthoses on plantar pressure distribution has been proven by researchers but there are some controversies about advantages of custom-made foot orthoses to less expensive prefabricated foot orthoses.

METHODS

Nineteen flatfeet adults between 18 and 45 participated in this study. CAD-CAM foot orthoses were made for these patients according to their foot scan. Prefabricated foot orthoses were prepared according to their foot size. Plantar pressure, force and contact area were measured using pedar^®-x in-shoe system wearing shoe alone, wearing CAD-CAM foot orthoses and wearing prefabricated foot orthoses. Repeated measures ANOVA model with post-hoc, Bonferroni comparison were used to test differences.

RESULTS

CAD-CAM and prefabricated foot orthoses both decreased pressure and force under 2nd, 3-5 metatarsal and heel regions comparing to shoe alone condition. CAD-CAM foot orthosis increased pressure under lateral toe region in comparison to shoe alone and prefabricated foot orthosis. Both foot orthoses increased pressure and contact area in medial midfoot region comparing to shoe alone condition. Increased forces were seen at hallux and lateral toes by prefabricated foot orthoses in comparison with CAD-CAM foot orthoses and control condition, respectively.

CONCLUSION

According to the results, both foot orthoses could decrease the pressure under heel and metatarsal area. It seems that the special design of CAD-CAM foot orthoses could not make great differences in plantar pressure distribution in this sample. Further research is required to determine whether these results are associated with different scan systems or design software.

Toward Pervasive Gait Analysis With Wearable Sensors: A Systematic Review

After decades of evolution, measuring instruments for quantitative gait analysis have become an important clinical tool for assessing pathologies manifested by gait abnormalities. However, such instruments tend to be expensive and require expert operation and maintenance besides their high cost, thus limiting them to only a small number of specialized centers. Consequently, gait analysis in most clinics today still relies on observation-based assessment. Recent advances in wearable sensors, especially inertial body sensors, have opened up a promising future for gait analysis. Not only can these sensors be more easily adopted in clinical diagnosis and treatment procedures than their current counterparts, but they can also monitor gait continuously outside clinics - hence providing seamless patient analysis from clinics to free-living environments. The purpose of this paper is to provide a systematic review of current techniques for quantitative gait analysis and to propose key metrics for evaluating both existing and emerging methods for qualifying the gait features extracted from wearable sensors. It aims to highlight key advances in this rapidly evolving research field and outline potential future directions for both research and clinical applications.

Beyond dichotomous thinking: a process perspective on diabetic foot disease

Background: Diabetic foot (DF) disease causes severe suffering around the world, and appropriate self-care activities are needed to prevent and treat this condition. However, all too often, self-care activities are less than optimal and clinicians find themselves unable to influence them in a positive direction. Clinicians' and researchers' mental models of the DF tend to be dichotomous: either the patient has or does not have an active ulcer or other DF disease. This mode of thinking hides the long-term perspective of DF disease, where patients' previous experiences and expectations for the future influence their current behavior. Thus, there is a need for a different perspective on DF disease to better understand patients' perspectives and thereby improve self-care, leading to more effective prevention and treatment. Objective: To present a novel framework, the process perspective on the DF, which can explain inadequate self-care behaviors not easily understood with a dichotomous perspective, and how they can be changed. Results: Three fictive clinical examples are used to illustrate how the process perspective on the DF can be used to understand how patients' previous experiences and expectations for the future influence their current behavior. In particular, this process perspective is used to understand how patients' beliefs and behaviors are sometimes self-reinforcing, resulting in stable behavior patterns, here referred to as 'DF cycles'. These cycles are quite common in clinical practice but are difficult to analyze using a dichotomous perspective on DF disease. The process perspective on the DF is used to analyze specific 'vicious' DF cycles of inadequate patient behavior and to find ways to transform them into 'virtuous' DF cycles, resulting in effective prevention and treatment. Conclusions: The process perspective on the DF seems suitable for understanding inadequate patient behaviors not easily understood with a dichotomous perspective on DF disease, opening up new avenues for clinical practice and research to help patients live a life with long remission phases, few relapses, and a high quality of life.

Effectiveness of Total Contact Orthosis for Plantar Pressure Redistribution in Neuropathic Diabetic Patients During Different Walking Activities

BACKGROUND

Using a total contact orthosis (TCO) is an effective method to offload in diabetic patients with foot neuropathy. However, the redistribution of peak plantar pressure is mostly observed during level walking, which may differ from other walking activities. The aim of this study was to investigate the plantar pressure from 4 regions of the foot during different walking activities (level walking, ramp ascending, ramp descending, stair ascending, and stair descending) in neuropathic diabetic patients with and without a TCO.

METHODS

Sixteen neuropathic diabetic patients aged 40 to 60 years with calluses and hallux valgus were included in this study and were provided with TCOs made up of multifoam, Plastazote, and microcellular rubber. The plantar pressure and contact area with the TCO and without the TCO were recorded using the Pedar X system during different walking activities.

RESULTS

A significant reduction of plantar pressure during different walking activities at the toes and forefoot regions was observed while walking with the TCO compared with walking without the TCO (control condition). Plantar pressure increased at the midfoot region when walking with the TCO, and no significant difference was observed at the hindfoot region between the control and TCO conditions. Furthermore, maximum contact area was observed during level walking with the TCO compared with other walking activities.

CONCLUSION

The TCO significantly reduced and redistributed the peak plantar pressure from the sites where the ulceration rate is higher at the toes and forefoot compared with the other regions of the foot.

LEVEL OF EVIDENCE

Therapeutic level II, lesser quality randomized controlled trial.

Effect of socks structures on plantar dynamic pressure distribution

A major purpose of investigating the plantar pressure in patients with pain or those at risk for skin injury is to reduce the pressure below metatarsal heads, specially first and second metatarsal heads. The aim of this article is to evaluate the effects of the socks structures on the changes in plantar dynamic pressure. In this study, seven socks types with different structures for the sole area were produced. The Gaitview^® AFA-50 system, a force plate, was used to measure the plantar dynamic pressure of 10 participants. The barefoot plantar dynamic pressure distribution was compared with the plantar dynamic pressure distribution with socks by two independent samples test on various zones of the foot and on different genders using SPSS software. Mann-Whitney tests were used to determine specific significant differences. The obtained results showed that the main trend was to redistribute the plantar dynamic pressure from the higher plantar pressure zones (toe and first through forth metatarsal bone regions) were decreased and as a result the plantar pressure toward the relatively lower pressure zones (fifth metatarsal bone and midfoot regions). In comparison with the barefoot condition, the cross miss structure reduced the mean pressure in the critical region of the foot (first metatarsal) for male and female subjects ( p < 0.05) and also the mock rib structure reduced the mean pressure for female subjects ( p < 0.05). In general, the results suggested wearing the socks because the socks make the plantar pressure redistributed from high to low plantar pressure zones. The results of this research indicated that wearing socks with cross miss and mock rib structures will reduce the mean plantar pressure values in forefoot area in comparison with the barefoot condition.

Establishment of a measurement method for in-shoe pressure and shear stress in specific regions for diabetic ulcer prevention

Pressure and shear stress are the factors of diabetic foot ulcers and callus formation. However, in-shoe shear stress of callus measurement could not have been measured because of technical difficulties. The purpose of this study is to verify reliability and validity of the established measurement system for in-shoe pressure and shear stress. For reliability, coefficients of variation (CV) and intraclass correlation coefficients (ICC) were confirmed. For known-groups validity, callus and non-callus feet were compared. Mean CV was 9.7%. Mean ICC was 0.943. For validity test, mean peak pressure and shear stress of the six callus feet was significantly higher than that of the eighteen non-callus feet. The pressure and shear stress that causes callus and diabetic foot ulcer will be identified in diabetic neuropathy patients.

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.

In shoe pressure measurements during different motor tasks while wearing safety shoes: The effect of custom made insoles vs. prefabricated and off-the-shelf

Health and safety regulations in many countries require workers at risk to wear safety shoes in a factory environment. These shoes are often heavy, rigid, and uncomfortable. Wearing safety shoes daily leads to foot problems, discomfort and fatigue, resulting also in the loss of numerous working days. Currently, knowledge of the biomechanical effects of insoles in safety shoes, during working activities, is very limited. Seventeen workers from a metalworking factory were selected and clinically examined for any foot conditions. Workers feet were 3D scanned, with regards to their plantar view, and the images used to design 34 custom-insoles, based on foot and safety shoe models. Three insoles were blind-tested by each worker: custom (CUS); prefabricated with the safety-shoe (PSS), and off-the-shelf (OTS). Foot-to-insole pressure distribution was measured in seven motor tasks replicating typical working activities: single and double-leg standing; weight lifting; stair ascending and descending; normal and fast walking. Wearing CUS within safety shoes resulted in a greater uniform pressure distribution across plantar regions for most of the working activities. Peak pressure at the forefoot during normal walking was the lowest in the custom insole (CUS 275.9±55.3kPa; OTS 332.7±75.5kPa; PSS 304.5±54.2kPa). Normal and fast walking were found to be the most demanding activities in terms of peak pressure. Wearing safety shoes results in high pedobarographic parameters in several foot regions. The use of custom insoles designed on the foot morphology helps decrease peak pressure and pressure-time integral compared to prefabricated featureless insoles.

Diabetic footwear: is it an assistive technology capable of reducing peak plantar pressures in elderly patients with neuropathy?

Abstract Introduction: Diabetes Mellitus is a chronic disease with high prevalence in the population in particular among the elderly. The longer time of diabetes, increased the chances of developing complications such as peripheral neuropathy, which is an important factor in the genesis of plantar lesions by changing the distribution and formation of plantar pressure peaks. Objective: Evaluate the influence of an Assistive Technology, therapeutic footwear for diabetics, in the peaks of plantar pressure of elderly. Methods: This was an experimental study of transversal type, composed by 10 elderly, diabetic, with peripheral neuropathy, using as an instrument to measure a baropodometry platform. Were measured peaks of plantar pressure, static and dynamic in three situations: barefoot, the participants' own standard footwear and with therapeutic footwear for diabetics. Data analysis by normal distribution as a single paired sample, applying the ANOVA test. Results: The use of therapeutic footwear for diabetics promoted a reduction in media of peak plantar pressure in the order of 22% in static analysis, and 31% in dynamic analysis. Conclusion: The therapeutic footwear for diabetics was able to produce significant reductions in peak plantar pressure, being more efficient than a common footwear. This effect may contribute to the prevention of injuries associated with the diabetic foot.

Effects of custom-made textile insoles on plantar pressure distribution and lower limb EMG activity during turning

Background

Turning during locomotion involves considerable changes of the body’s center of mass and reduced stability, as well as lower limb kinematics and kinetics. However, many previous studies have been carried out to evaluate the effectiveness and applications of orthotic insoles as well as different types of orthotic materials in various clinical symptoms, which are focused primarily on straight line walking. Hence, the influence of custom-made insoles with the use of advanced three-dimensional spacer fabrics on biomechanics parameters in terms of plantar pressure distribution and lower limb electromyography during turning movement was studied.

Methods

Twelve subjects performed 180-degree turning at a speed 3.07-3.74 km/h for five successful trials under 3 insoles conditions: wearing traditional ethylene vinyl acetate insoles and two different spacer-fabricated insoles, with the plantar pressure and lower limb muscle activity collected simultaneously. Turning movement was broken down into 3 phases for analysis: Turning initiation, turn around and turn termination.

Results

There was a statistically significance difference in plantar pressure between the traditional insoles and the insoles made of a spacer fabric as the top layer (p < 0.05). Compared to the traditional insoles, insoles made of a spacer fabric reduced the peak pressure (>12 %) and pressure–time integral (>13 %) in toes, metatarsal head 1 and metatarsal heads 2–3 at turning initiation; (>15 %) and (>17 %) in medial midfoot and medial heel at turn around. Insoles with spacer fabrics on the top and middle layer reduced both pressure parameters (>18 %) in toes and MTH 1 at turn termination. In terms of muscle activities, insoles with two-layer spacer fabrics could lower maximum muscle activities of vastus lateralis (>16 %; p < 0.05) at turn around.

Conclusions

Insoles with different fabrications could offer various pressure offloading patterns across the plantar and muscle activity changes while turning. Insoles with a spacer fabric on the top tend to reduce plantar pressure loading at different regions during turn initiation and turn around phases, while two-layer spacer-fabricated insoles may contribute to reduced vastus lateralis muscle activation during turn around. More importantly, this study provides a new dimension in the potential use of the textile-fabricated insoles which may widen the range of insole materials selection in the design and development of insoles so as to enhance the effectiveness of orthotic treatment.

Footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in patients with diabetes: a systematic review

BACKGROUND

Footwear and offloading techniques are commonly used in clinical practice for preventing and healing of foot ulcers in persons with diabetes. The goal of this systematic review is to assess the medical scientific literature on this topic to better inform clinical practice about effective treatment.

METHODS

We searched the medical scientific literature indexed in PubMed, EMBASE, CINAHL, and the Cochrane database for original research studies published since 1 May 2006 related to four groups of interventions: (1) casting; (2) footwear; (3) surgical offloading; and (4) other offloading interventions. Primary outcomes were ulcer prevention, ulcer healing, and pressure reduction. We reviewed both controlled and non-controlled studies. Controlled studies were assessed for methodological quality, and extracted key data was presented in evidence and risk of bias tables. Uncontrolled studies were assessed and summarized on a narrative basis. Outcomes are presented and discussed in conjunction with data from our previous systematic review covering the literature from before 1 May 2006.

RESULTS

We included two systematic reviews and meta-analyses, 32 randomized controlled trials, 15 other controlled studies, and another 127 non-controlled studies. Several randomized controlled trials with low risk of bias show the efficacy of therapeutic footwear that demonstrates to relief plantar pressure and is worn by the patient, in the prevention of plantar foot ulcer recurrence. Two meta-analyses show non-removable offloading to be more effective than removable offloading for healing plantar neuropathic forefoot ulcers. Due to the limited number of controlled studies, clear evidence on the efficacy of surgical offloading and felted foam is not yet available. Interestingly, surgical offloading seems more effective in preventing than in healing ulcers. A number of controlled and uncontrolled studies show that plantar pressure can be reduced by several conservative and surgical approaches.

CONCLUSIONS

Sufficient evidence of good quality supports the use of non-removable offloading to heal plantar neuropathic forefoot ulcers and therapeutic footwear with demonstrated pressure relief that is worn by the patient to prevent plantar foot ulcer recurrence. The evidence base to support the use of other offloading interventions is still limited and of variable quality. The evidence for the use of interventions to prevent a first foot ulcer or heal ischemic, infected, non-plantar, or proximal foot ulcers is practically non-existent. High-quality controlled studies are needed in these areas.

A study of the immediate effects of glycerine-filled insoles, contoured prefabricated orthoses and flat insoles on single-leg balance, gait patterns and perceived comfort in healthy adults

Background

Footwear interventions are often prescribed to assist with the management of lower limb pain, injury and disease. Commercially available shoe insoles and orthoses are increasingly incorporating novel design features to alleviate foot and lower limb symptoms, but this may be at a cost to optimal functional performance. This study compared the immediate effects of wearing glycerine-filled insoles, contoured prefabricated orthoses, and flat insoles, on balance and gait measures.

Methods

Thirty healthy adults (17 men, 13 women; mean [SD] age: 24.3 [2.5] years) performed tests of single-leg standing with eyes open (Kistler force platform), star excursion balance test, and level-ground walking (GAITRite® walkway system), under three randomised conditions: wearing glycerine-filled insoles, prefabricated orthoses, and flat (control) insoles, within their own footwear. Centre of pressure movement (anterior-posterior and mediolateral range and standard deviation, total path velocity), star excursion balance test reach distance, and temporospatial gait variables were collected. Perceived comfort of the inserts was scored immediately after use on a 100 mm visual analogue rating scale. After trialling all inserts each participant ranked their level of comfort from least to most.

Results

Centre of pressure measures, star excursion balance test reach distance, or temporospatial gait variables did not differ between the three inserts (all P values >0.088). Significant between-condition differences were reported for comfort ranking (P = 0.031), but not rating scores (P = 0.638). Weak to moderate negative correlations (r values ranged between −0.368 and −0.406) were observed between visual analogue scale comfort rating for the flat insoles and prefabricated orthoses, star excursion balance test and gait measures.

Conclusions

Single-leg standing balance, star excursion balance test performance, and level-ground walking patterns in asymptomatic adults do not appear to differ when wearing glycerine-filled insoles, contoured prefabricated orthoses, or flat insoles. Perceived comfort may be related to the biomechanical or clinical effectiveness of novel footwear interventions, and requires further investigation. Importantly, these findings are specific to a healthy population and further research is needed to determine the long-term effects of glycerine-filled insoles in patients with known balance impairments.

Analysis of Ulcer Recurrences After Metatarsal Head Resection in Patients Who Underwent Surgery to Treat Diabetic Foot Osteomyelitis

Metatarsal head resection is a common and standardized treatment used as part of the surgical routine for metatarsal head osteomyelitis. The aim of this study was to define the influence of the amount of the metatarsal resection on the development of reulceration or ulcer recurrence in patients who suffered from plantar foot ulcer and underwent metatarsal surgery. We conducted a prospective study in 35 patients who underwent metatarsal head resection surgery to treat diabetic foot osteomyelitis with no prior history of foot surgeries, and these patients were included in a prospective follow-up over the course of at least 6 months in order to record reulceration or ulcer recurrences. Anteroposterior plain X-rays were taken before and after surgery. We also measured the portion of the metatarsal head that was removed and classified the patients according the resection rate of metatarsal (RRM) in first and second quartiles. We found statistical differences between the median RRM in patients who had an ulcer recurrence and patients without recurrences (21.48 ± 3.10% vs 28.12 ± 10.8%; P = .016). Seventeen (56.7%) patients were classified in the first quartile of RRM, which had an association with ulcer recurrence (P = .032; odds ratio = 1.41; 95% confidence interval = 1.04-1.92). RRM of less than 25% is associated with the development of a recurrence after surgery in the midterm follow-up, and therefore, planning before surgery is undertaken should be considered to avoid postsurgical complications.

Comparison of plantar pressure in three types of insole given to patients with diabetes at risk of developing foot ulcers - A two-year, randomized trial

Background

Special insoles and shoes designed to prevent foot ulcers caused by repetitive high pressures are recommended for patients with diabetes who have any of the following risk factors: neuropathy; peripheral vascular disease; foot deformities; previous ulcers; amputation; and skin pathologies. However, there is a need for increased knowledge regarding: a) differences in the peak pressure (PP) and pressure time integral (PTI) for different types of insoles; and b) the properties of the pressure distribution for insoles used over a period of several months. We present the results of a randomized trial to compare the plantar pressures of three commonly used insoles.

Objectives

The primary objective was to compare the PP and PTI between three types of insoles. The secondary objective was to explore the long-term pattern of peak plantar pressure distribution and variations in specific regions of interest (ROI). The tertiary objective was to investigate the impacts of insole adjustments, how much the insoles were used, and the levels of patient satisfaction.

Methods

In a 2-year trial, 114 patients with type 1 (N = 31) or type 2 (N = 83) diabetes (62 men and 52 women; mean age, 57.7 ± 15.4 years; duration of diabetes, 12.3 ± 11.2 years; neuropathy, 38%), were randomized to be supplied with one of three different insoles. The ethylene vinyl acetate (EVA) insoles were used in outdoor walking shoes. The 35 EVA group (N = 39) received soft custom-made insoles composed of EVA of 35 shore A hardness, the 55 EVA group (N = 37) received custom-made insoles composed of EVA of 55 shore hardness, and the control group (N = 38) received prefabricated insoles composed of a hard core with a top layer of soft 12 shore hardness microfiber. Using F-Scan^®, the in-shoe plantar pressures were measured at seven ROI (hallux, metatarsal head 1, metatarsal head 2, metatarsal head 4, metatarsal head 5, lateral aspect of the mid-foot, heel) on five occasions during the study period. The plantar-pressure variables used were PP (main outcome) and PTI. The plantar patterns of load were explored, satisfaction and usage of the insoles were rated by the participants, and insole adjustments were recorded.

Results

A mixed model analysis estimated lower PP values in the heel regions for the 35 EVA and 55 EVA insoles (171 ± 13 and 161 ± 13 kPa, respectively) than for the prefabricated insoles (234 ± 10 kPa) (p < 0.001). Also for some of the other six ROI indications of difference in PP or PTI could be observed. The redistribution of peak plantar pressure for all of the insoles, was stable at the mid-foot, while the proportion of load on the distal area changed during the study period According to the self-reported answers (scale, 0–100), the average usage of the insoles was rated as 79 and satisfaction was rated as 85 (N = 75). Thirty-two percent of the subjects had not received foot care. Fourteen adjustments to insoles were made during the study period, and 86 pairs of insoles were exchanged due to wear, with 49% being exchanged in the 35 EVA group.

Conclusions

Custom-made insoles used in combination with stable walking shoes gave lower pressures at the heel region. The variation makes it difficult to detect a systematic difference in plantar pressure for the 6 ROI, if such a difference indeed exists. The levels of satisfaction and usage for all the insoles tested were high. The insoles maintained their pressure redistribution properties over long periods, and few adjustments were needed.

Development and evaluation of prefabricated antipronation foot orthosis

Our aim was to develop and evaluate a new antipronation foot orthosis that addressed problems perceived by clinicians and users with existing foot orthoses. Clinicians and users were engaged to develop a user specification for the orthosis, and orthotic geometry and materials were developed using clinical reasoning. The orthotic material properties were tested and the ability of the orthosis to reduce foot pronation evaluated on 27 individuals. Clinicians expressed concern that current prefabricated orthoses often did not offer sufficient support to the foot because of a combination of the shape and materials used, and users concurred but also highlighted issues of durability and hygiene. The geometry of the new orthosis was, therefore, adjusted to enable individual foot size orthoses to be produced. A material was selected that was harder and more durable than materials used in many prefabricated orthoses. When the new orthosis was being worn, maximum rear foot eversion was reduced in both walking (mean reduction -3.8 degrees, p < 0.001) and running (mean reduction -2.5 degrees, p < 0.001). Through a structured process, orthotic design decisions were made that addressed the specific concerns of clinicians and users and the new orthosis was proven to reduce rearfoot pronation.

Foot orthoses custom-made by vacuum forming on the non-load-bearing foot: preliminary results in male children with calcaneal apophysitis (Sever's disease)

BACKGROUND AND AIM

To our knowledge, the technique of molding orthoses to the non-load-bearing foot is still not widely investigated. The aim of this work is, therefore, first, to describe an off-loading custom-made technique and, second, to explain how it can be specifically adapted to treat Sever's disease.

TECHNIQUES

A technique of directly molding orthoses to the non-load-bearing foot by vacuum forming an insole to the foot fabricated with a combination of polyvinyl chloride and polyester resins, 30 Shore A hardness and 148 kg/m(3) density polyethylene-ethylene-vinyl-alcohol, and a cushioning heel cup of 22 Shore A polyurethane, using a directly molding orthoses technique to the non-load-bearing foot by vacuum.

DISCUSSION

Results show that this new technique could be a good alternative to traditional insoles in the management of Sever's disease pain.