Plantar pressure as a risk assessment tool for diabetic foot ulceration in egyptian patients with diabetes

Pedobarographic evaluations in physical medicine and rehabilitation practice

The feet are complex structures that transmit loads transferred by other parts of the body to the ground and are involved in many static and dynamic activities, such as standing and walking. The contact area and pressure changes between the feet and the ground surface can be measured using pedobarographic devices. With pedobarographic examinations, it is possible to obtain a wide range of information needed to support clinical evaluation and diagnostic tests in physical medicine and rehabilitation practice. Foot structure and function, postural stability, lower extremity biomechanics, and gait analysis are among the areas that can be further investigated using pedobarography.

A qualitative exploration of adherence to wearing removable cast walkers in patients with diabetic foot ulcers

OBJECTIVE

To explore adherence to wearing removable cast walkers (RCWs) among patients with diabetic foot ulcers (DFUs).

METHOD

A qualitative study was conducted by interviewing patients with active DFUs and using knee-high RCWs as their offloading treatment. The interviews were undertaken at two diabetic foot clinics in Jordan, using a semi-structured guide. Data were analysed through content analysis by developing main themes and categories.

RESULTS

Following interviews with 10 patients, two main key themes with a total of six categories were identified: theme 1-reporting of adherence levels was inconsistent, included two categories: i) a belief in achieving optimal adherence, and ii) non-adherence was often reported indoors; and theme 2-adherence was a consequence of multiple psychosocial, physiological and environmental factors, which included four categories: i) specific offloading knowledge or beliefs influenced adherence; ii) severity of foot disease influenced adherence; iii) social support benefitted adherence; and iv) physical features of RCWs (the usability of the offloading device) impacted adherence.

CONCLUSION

Patients with active DFUs reported inconsistent levels of adherence to wearing RCWs which, after deeper investigation, seemed to be due to participants' misperceptions of the optimal adherence. Adherence to wearing RCWs also seemed to be impacted by multiple psychosocial, physiological and environmental factors.

Early detection and treatment device for diabetic foot neuropathy

BACKGROUND

Diabetic foot neuropathy is one of the complications of diabetes that affects around 50% of diabetic people. Because peripheral neuropathy involves nerve loss around the foot areas, patients with diabetic neuropathy frequently lose sensation in their feet while walking or standing. Furthermore, since sensory nerves are damaged, the area that holds the majority of the foot pressure and temperature is at high risk of injury. If not diagnosed and treated properly, it can cause foot injury and eventually lead to edema, gangrene, ulcers, amputation, and even death. There are now several techniques of detecting diabetic neuropathy, but they are limited in their availability, cost-effectiveness, and complexity.

AIMS

The primary goal of this research was to develop devices for early detection and treatment of diabetic foot neuropathy.

METHODS

The proposed device combines a foot pressure monitoring method and a foot temperature measurement method to diagnose diabetic neuropathy early on, with red light therapy added as a treatment method. For 2 weeks, the device measures the patient's foot pressure and temperature, and light therapy is provided if a change in pressure or temperature at a specific area is observed.

RESULTS

The device prototype was successfully developed, and numerous tests were carried out in accordance with the design specifications. For pressure measurement and temperature measurement, measurement accuracy of 99.05% and 99.30%, respectively, were attained.

CONCLUSION

The early detection and treatment device developed in this study could be used at home by diabetic patients as well as in hospitals to test for and treat diabetic foot neuropathy at an early stage. The device incorporates two different methods of diabetic foot neuropathy detection with high measurement accuracy which makes it suitable for use in resource-limited areas at low cost. The incorporation of red light therapy together with the two methods of diabetic neuropathy detection gives another unique feature for our device.

Smart Shoe Insole Based on Polydimethylsiloxane Composite Capacitive Sensors

Nowadays, the study of the gait by analyzing the distribution of plantar pressure is a well-established technique. The use of intelligent insoles allows real-time monitoring of the user. Thus, collecting and analyzing information is a more accurate process than consultations in so-called gait laboratories. Most of the previous published studies consider the composition and operation of these insoles based on resistive sensors. However, the use of capacitive sensors could provide better results, in terms of linear behavior under the pressure exerted. This behavior depends on the properties of the dielectric used. In this work, the design and implementation of an intelligent plantar insole composed of capacitive sensors is proposed. The dielectric used is a polydimethylsiloxane (PDMS)-based composition. The sensorized plantar insole developed achieves its purpose as a tool for collecting pressure in different areas of the sole of the foot. The fundamentals and details of the composition, manufacture, and implementation of the insole and the system used to collect data, as well as the data samples, are shown. Finally, a comparison of the behavior of both insoles, resistive and capacitive sensor-equipped, is made. The prototype presented lays the foundation for the development of a tool to support the diagnosis of gait abnormalities.

Effects of Walking Speeds and Durations on Peak Plantar Pressures

BACKGROUND

Walking at various speeds and durations may result in different peak plantar pressure (PPP). However, there is no study comparing the effect of walking speeds and durations on PPP. The purpose of this study was to explore whether different walking speeds and durations significantly change PPP and establish a normal response in healthy people.

METHODS

An in-shoe plantar pressure system was used to measure PPP under the first toe, first metatarsal, second metatarsal, and heel regions in 12 healthy, young people. All participants performed six walking trials at three speeds (3, 6, and 9 km/h) and for two durations (10 and 20 min). The 3 × 2 two-way analysis of variance was used to examine the main effects of speeds and durations and their interaction.

RESULTS

The results showed that walking speeds significantly affected PPP and that walking duration did not. No interaction between the walking speed and duration was observed. Peak plantar pressure values under the first toe and the first metatarsal head were significantly higher (P < .05) at 9 km/h (509.1 ± 314.2 kPa and 591.4 ± 302.4 kPa, respectively) than at 3 km/h (275.4 ± 168.7 kPa and 369.4 ± 205.4 kPa, respectively) after 10-min walking.

CONCLUSIONS

People at risk for foot ulcers may use slow and brisk walking for exercise to reduce PPP, thus reducing risk for foot ulcers. Our study demonstrated that slow running at 9 km/h significantly increases PPP.

Factors associated with changes in plantar pressure of people with peripheral diabetic neuropathy

Abstract

Diabetic neuropathy is one of the main complications of Diabetes Mellitus, which can lead to loss of protective sensation, motor, and plantar pressure alteration, generating deformities, abnormal gait and mechanical trauma to the feet.

Objective

to evaluate the distribution of plantar pressure, sensorimotor changes, balance and associated factors to plantar pressure changes in people with peripheral diabetic neuropathy.

Method

Cross-sectional study conducted with individuals registered in the primary public health service of a city in the east of São Paulo - Brazil. The sample was composed by people with Diabetes Mellitus and Peripheral Neuropathy identified by the Michigan Screening Instrument. It were investigated variables such as sensory-motor changes, static and dynamic plantar pressure using baropodometry and balance using the Berg scale. A significance level of 5% was adopted for all tests used.

Results

Of the 200 individuals evaluated, 52.55% had no plantar protective sensitivity, the static evaluation did not demonstrated changes in the peak of plantar pressure, however in the dynamics the mean in the right foot was 6.0 (±2) kgf/cm2 and 6,7 (±1.62) kgf/cm2 on the left foot, the center of static pressure on the right foot was lower (10.55 ± 3.82) than on the left foot (11.97 ± 3.90), pointing hyper plantar pressure. The risk of falling was high, ranging from 8 to 56 points, with an average of 40.9 (±10.77).

Conclusion

The absence of protective plantar sensitivity, increased pressure, biomechanical changes lead to loss of balance and are predictive of complications in the feet due to diabetic neuropathy.

Effects of walking speeds and durations on the plantar pressure gradient and pressure gradient angle

BACKGROUND

Walking exercise has been demonstrated to improve health in people with diabetes. However, it is largely unknown the influences of various walking intensities such as walking speeds and durations on dynamic plantar pressure distributions in non-diabetics and diabetics. Traditional methods ignoring time-series changes of plantar pressure patterns may not fully capture the effect of walking intensities on plantar tissues. The purpose of this study was to investigate the effect of various walking intensities on the dynamic plantar pressure distributions. In this study, we introduced the peak pressure gradient (PPG) and its dynamic patterns defined as the pressure gradient angle (PGA) to quantify dynamic changes of plantar pressure distributions during walking at various intensities.

METHODS

Twelve healthy participants (5 males and 7 females) were recruited in this study. The demographic data were: age, 27.1 ± 5.8 years; height, 1.7 ± 0.1 m; and weight, 63.5 ± 13.5 kg (mean ± standard deviation). An insole plantar pressure measurement system was used to measure plantar pressures during walking at three walking speeds (slow walking 1.8 mph, brisk walking 3.6 mph, and slow running 5.4 mph) for two durations (10 and 20 min). The gradient at a location is defined as the unique vector field in the two-dimensional Cartesian coordinate system with a Euclidean metric. PGA was calculated by quantifying the directional variation of the instantaneous peak gradient vector during stance phase of walking. PPG and PGA were calculated in the plantar regions of the first toe, first metatarsal head, second metatarsal head, and heel at higher risk for foot ulcers. Two-way ANOVA with Fisher's post-hoc analysis was used to examine the speed and duration factors on PPG and PGA.

RESULTS

The results showed that the walking speeds significantly affect PPG (P < 0.05) and PGA (P < 0.05), and the walking durations does not. No interaction between the walking duration and speed was observed. PPG in the first toe region after 5.4 mph for either 10 or 20 min was significantly higher than 1.8 mph. Meanwhile, after 3.6 mph for 20 min, PPG in the heel region was significantly higher than 1.8 mph. Results also indicate that PGA in the forefoot region after 3.6 mph for 20 min was significantly narrower than 1.8 mph.

CONCLUSIONS

Our findings indicate that people may walk at a slow speed at 1.8 mph for reducing PPG and preventing PGA concentrated over a small area compared to brisk walking at 3.6 mph and slow running at 5.4 mph.

Development of a low-cost textile sensor based insole to monitor foot pressure of diabetic patients

A common but preventable complication of diabetes is diabetic foot ulcer. If appropriate care is not provided such foot lesions progress to the most severe diabetic foot complication, like infection, gangrene, amputation and even death. Diabetic neuropathy results abnormal planter pressure points under the foot and triggers the tendency of foot ulcer. The aim of this paper is to present the development of a low cost, power efficient, soft, lightweight and simple in-shoe planter pressure measurement system. The system is capable to determine the average static pressure under ball and heel of the foot. The insole is comfortable due to the use of textile pressure sensor and its simple data acquisition method makes operation easy for the users. An experiment with 10 participants with and without diabetes was carried out to observe the outcome of the system. The practical implication of this study is to minimise the damage caused by foot ulcer by determining the pressure abnormality at earliest with a fully developed cost effective design. The system is capable to identify the difference in average planter pressure values in different groups of participants. To monitor the foot health proactively, the proposed system is found to be a useful device and can successfully scan the planter pressure under ball and heel of the foot.

Using Manchester Scale classification of Hallux Valgus as a valuable tool in determining appropriate risk categorization during initial diabetic foot screening in primary health care settings

Limitations have been identified in the current state of primary care practises with regards to identifying and correctly categorizing foot deformity and its associated risk of developing foot ulcers in patients with diabetes. This study aims to bridge these gaps through the implementation of additional categorization tools to be made available for primary care professionals. This study thus analysed the relationship between foot pressure distribution and amount in patients with diabetes with Hallux Valgus foot deformity, and its different stages, in order to better understand the clinical applications of the Manchester Scale. Statistically significant data in pressure distribution (P < 0.05) was found in all three severity groups identified by the Manchester Scale (Mild, Moderate and Severe) when compared to a No deformity group. However, only the Severe Hallux Valgus group crossed the threshold over 500 kPa in the area of first metatarsal bone. Further research should aim to analyse pressure distribution and amount in patients with both diabetes and diabetic neuropathy of all stages of Hallux Valgus.

In-shoe pressure thresholds for people with diabetes and neuropathy at risk of ulceration: A systematic review

INTRODUCTION

In-shoe pressure thresholds play an increasingly important role in the prevention of diabetes-related foot ulceration (DFU). The evidence of their effectiveness, methodological consistency and scope for refinement are the subject of this review.

METHODS

1107 records were identified (after duplicate removal) based on a search of five databases for studies which applied a specific in-shoe pressure threshold to reduce the risk of ulceration. 37 full text studies were assessed for eligibility of which 21 were included.

RESULTS

Five in-shoe pressure thresholds were identified, which are employed to reduce the risk of diabetes-related foot ulceration: a mean peak pressure threshold of 200 kPa used in conjunction with a 25% baseline reduction target; a sustained pressure threshold of 35 mm Hg, a threshold matrix based on risk, shoe size and foot region, and a 40-80% baseline pressure reduction target. The effectiveness of the latter two thresholds have not been assessed yet and the evidence for the effectiveness of the other in-shoe pressure thresholds is limited, based only on two RCTs and two cohort studies.

CONCLUSIONS

The heterogeneity of current measures precludes meta-analysis and further research and methodological standardisation is required to facilitate ready comparison and the further development of these pressure thresholds.

Effect of tap dance on plantar pressure, postural stability and lower body function in older patients at risk of diabetic foot: a randomized controlled trial

INTRODUCTION

To examine the effects of tap dance (TD) on dynamic plantar pressure, static postural stability, ankle range of motion (ROM), and lower extremity functional strength in patients at risk of diabetic foot (DF).

RESEARCH DESIGN AND METHODS

A randomised, single-blinded, two-arm prospective study of 40 patients at risk of DF was conducted. The intervention group (n=20) received 16 weeks of TD training (60 min/session×3 sessions/week). The control group attended four educational workshops (1 hour/session×1 session/month). Plantar pressure, represented by the primary outcomes of peak pressure (PP) and pressure-time integral (PTI) over 10 areas on each foot, was measured using the Footscan platform system. Secondary outcomes comprised static postural stability, ankle ROM and lower extremity functional strength.

RESULTS

Reductions in intervention group PP (right foot: mean differences=4.50~27.1, decrease%=25.6~72.0; left foot: mean differences=-5.90~6.33, decrease%=-22.6~53.2) and PTI at 10 areas of each foot (right foot: mean differences=1.00~12.5, decrease%=10.4~63.6; left foot: mean differences=0.590~25.3, decrease%=21.9~72.6) were observed. Substantial PP and PTI differences were noted at the second through fourth metatarsals, medial heel and lateral heel in the right foot. Substantial PP and PTI differences were detected at metatarsals 1 and 2 and metatarsal 2 in the left foot, respectively. Moderate training effects were found in plantar flexion ROM of both feet, lower extremity functional strength, and length of center-of-pressure trajectory with eyes closed and open (r=0.321-0.376, p<0.05).

CONCLUSIONS

A 16-week TD training program can significantly improve ankle ROM, lower extremity functional strength, and static postural stability. To attain greater improvements in plantar pressure, a longer training period is necessary.

TRIAL REGISTRATION NUMBER

ChiCTR1800014714.

A Novel Low-Cost Wireless Footwear System for Monitoring Diabetic Foot Patients

Diabetic foot is one of the main complications of diabetes with the characteristics of high incidence and difficulty in treatment. Diabetic patients with peripheral neuropathy may develop foot ulcers, and in severe cases amputations are required and some may even die. Plantar pressure can be used to assess the risk of developing diabetic foot, but the existing plantar pressure monitoring methods are not suitable for long-term monitoring in daily life. This study presents a novel low-cost shoe system for daily monitoring of plantar pressure in diabetics. It includes an insole with pressure sensor array, which can dynamically monitor the plantar pressure and display the changes of plantar pressure in real time in the mobile phone to provide early warning for patients with high risk of diabetic foot. As for the sensor, copper and carbon black were adopted as the electrode and conductive filler respectively, enabling a mass production with low price. It was soft and bendable, meeting the performance needs of daily plantar pressure monitoring. All devices were encapsulated in shoes, and the data was transmitted wirelessly through Bluetooth, which did not affect the user's walking. After using random forest for feature selection, five classifiers were used to classify the plantar pressure of healthy people, diabetic patients without peripheral neuropathy, and diabetic patients with peripheral neuropathy collected by this system. The experimental results showed that the accuracy of the random forest classifier was the highest, reaching 94.7%, which indicated that the system could be useful for daily plantar pressure monitoring of diabetic patients.

A Simple Foot Plantar Pressure Measurement Platform System Using Force-Sensing Resistors

Generally, there are two types of working style, i.e., some people work in sitting conditions, and the remaining work mostly in a standing position. For people working in a standing position, they can spend hours in a day doing their work standing. These people do not realize that it can cause medical issues, especially for the feet, namely biometric problems. In addition, several doctors in Indonesia are already aware of this issue and state that the biometric problems faced by those kinds of people can be predicted from the load distribution on the foot. However, the tool used by the doctors in Indonesia to measure biometric problems is not a digital tool. Therefore it is very difficult to measure and predict the biometric problems quantitatively. This study aims to develop a low-cost static load measuring device using force-sensing resistor (FSR) sensors. The measuring instrument is designed in the form of a pressure plate platform which consist of 30 FSR 402 sensors. The sensors are placed right underneath the display area of the foot, 15 sensors on the soles of the left and right feet. Ten students from the Department of Mechanical Engineering, Diponegoro University (five men and five women) were asked to stand on the platform. Each subject also measured foot length (FL) to estimate shoe size, foot area contact (FAC) for validation between genders, and foot type using the digital footprint tools. From the results of measurements obtained for the left foot in the medial mid foot area, i.e., in sensors 5 and 7, not exposed to the load, on almost all subjects except subject number 3 with a load of 0.196 kg on sensor 7. The highest average load occurs in the heel area i.e., sensor 1 measured 0.713 kg and the smallest average load occurs in the five sensors, with 0 kg. A static load gauge that is designed to be used to measure each leg area for subjects with a shoe size of 40–42 with low price to be held in hospital-orthopedic hospitals and biomechanical research centers.

Gait analysis - Available platforms for outcome assessment

Movement or gait analysis has become a viable assessment tool not only used in sports science or basic biomechanical research, but has also expanded to be a very valuable instrument in clinical diagnostics, monitoring functional recovery and musculoskeletal rehabilitation. In this context, this method has long been an integral part solely in neurological disorders such as cerebral palsy. However, in the meantime the benefits have also become apparent in other medical areas, such as foot surgery, orthopaedic technology, or in patients after lower limb amputation. These procedures proved to better understand, objectify and quantify the individual causes of gait and movement disorders in order to optimize patient-specific therapy. Currently we are able to rely on a multitude of available measurement systems. These can either be used in everyday life for simple monitoring of one's own activity or to complement therapeutic approaches in the clinical and scientific environment. The following review highlights the various fields of movement analysis, including markerless motion capture, marker-based analysis, pedobarography and wearable sensors. Each of these areas presents its own field of application and potential usage as well as the advantages and disadvantages arising in this context. The following article will give an overview of the type of measurement technology used, the respective fields of application, and the selected parameters and their interpretation possibilities for each of the areas mentioned.

Prediction of Diabetic Foot Ulceration: The Value of Using Microclimate Sensor Arrays

BACKGROUND

Accurately predicting the risk of diabetic foot ulceration (DFU) could dramatically reduce the enormous burden of chronic wound management and amputation. Yet, the current prognostic models are unable to precisely predict DFU events. Typically, efforts have focused on individual factors like temperature, pressure, or shear rather than the overall foot microclimate.

METHODS

A systematic review was conducted by searching PubMed reports with no restrictions on start date covering the literature published until February 20, 2019 using relevant keywords, including temperature, pressure, shear, and relative humidity. We review the use of these variables as predictors of DFU, highlighting gaps in our current understanding and suggesting which specific features should be combined to develop a real-time microclimate prognostic model.

RESULTS

The current prognostic models rely either solely on contralateral temperature, pressure, or shear measurement; these parameters, however, rarely reach 50% specificity in relation to DFU. There is also considerable variation in methodological investigation, anatomical sensor configuration, and resting time prior to temperature measurements (5-20 minutes). Few studies have considered relative humidity and mean skin resistance.

CONCLUSION

Very limited evidence supports the use of single clinical parameters in predicting the risk of DFU. We suggest that the microclimate as a whole should be considered to predict DFU more effectively and suggest nine specific features which appear to be implicated for further investigation. Technology supports real-time in-shoe data collection and wireless transmission, providing a potentially rich source of data to better predict the risk of DFU.

Active smoking among people with diabetes mellitus or hypertension in Africa: a systematic review and meta-analysis

The objective was to summarize existing data on the prevalence of active tobacco smoking among patients with hypertension or diabetes mellitus in Africa. We searched PubMed, EMBASE, and AJOL to include studies published from January 01, 2000 to August 23, 2017 reporting on the prevalence of active smoking in individuals aged ≥15 years with hypertension or diabetes mellitus residing inside Africa. We used a random-effects meta-analysis model to pool studies. The pooled prevalence of active smoking among patients with hypertension or diabetes was 12.9% (95%CI: 10.6–15.3; 50 studies; 16,980 patients) and 12.9% (95%CI: 9.6–16.6; 42 studies; 18,564 patients), respectively. For both conditions, the prevalence of active smoking was higher in males than in females (p < 0.001), and in Northern compared to sub-Saharan Africa (p < 0.001). There was no difference between urban and rural settings, and between community-based and hospital-based studies, except for patients with diabetes for whom the prevalence was higher in hospital-based studies (p = 0.032). The prevalence of active smoking is high among patients with hypertension or diabetes mellitus in Africa, with the heaviest burden in Northern Africa. Interventions for smoking prevention or cessation should be implemented in these high risk populations, targeting particularly the males.

Foot Kinetic and Kinematic Profile in Type 2 Diabetes Mellitus with Peripheral Neuropathy A Hospital-Based Study from South India

BACKGROUND

A kinetic change in the foot such as altered plantar pressure is the most common etiological risk factor for foot ulcers in people with diabetes mellitus. Kinematic alterations in joint angle and spatiotemporal parameters of gait have also been frequently observed in participants with diabetic peripheral neuropathy (DPN). Diabetic peripheral neuropathy leads to various microvascular and macrovascular complications of the foot in type 2 diabetes mellitus. There is a gap in the literature for biomechanical evaluation and assessment of type 2 diabetes mellitus with DPN in the Indian population. We sought to assess and determine the biomechanical changes, including kinetics and kinematics, of the foot in DPN.

METHODS

This cross-sectional study was conducted at a diabetic foot clinic in India. Using the purposive sampling method, 120 participants with type 2 diabetes mellitus and DPN were recruited. Participants with active ulceration or amputation were excluded.

RESULTS

The mean ± SD age, height, weight, body mass index, and diabetes duration were 57 ± 14 years, 164 ± 11 cm, 61 ± 18 kg, 24 ± 3 kg/m², and 12 ± 7 years, respectively. There were significant changes in the overall biomechanical profile and clinical manifestations of DPN. The regression analysis showed statistical significance for dynamic maximum plantar pressure at the forefoot with age, weight, height, diabetes duration, body mass index, knee and ankle joint angle at toe-off, pinprick sensation, and ankle reflex ( R = 0.71, R² = 0.55, F_12,108 = 521.9 kPa; P = .002).

CONCLUSIONS

People with type 2 diabetes mellitus and DPN have significant changes in their foot kinetic and kinematic parameters. Therefore, they could be at higher risk for foot ulceration, with underlying neuropathy and biomechanically associated problems.

The influence of population characteristics and measurement system on barefoot plantar pressures: A systematic review and meta-regression analysis

BACKGROUND

The measurement of plantar pressure distributions during gait can provide insights into the effects of musculoskeletal disease on foot function. A range of hardware, software, and protocols are available for the collection of this type of data, with sometimes disparate and conflicting results reported between individual studies. In this systematic review and meta-regression analysis of dynamic regional peak pressures, we aimed to test if 1) the system used to obtain the pressure measurements and 2) the characteristics of the study populations had a significant effect on the results.

METHODS

A systematic review of the literature was undertaken to identify articles reporting regional peak plantar pressures during barefoot walking. A mixed-effects modeling approach was used to analyze the extracted data. Initially, the effect of the system used to collect the data was tested. Following this, the effect of participant characteristics on the results were analyzed, using moderators of cohort type (defined as the primary health characteristic of the participants), age, sex, and BMI.

RESULTS

115 participant groups were included in the analysis. Sufficient cohorts were available to test those that consisted of healthy individuals, and those with diabetes and diabetic neuropathy. Significant differences were found between results reported by studies using different pressure measurement systems in 8 of the 16 regions analyzed. The analysis of participant characteristics revealed a number of significant relationships between regional peak pressures and participant characteristics, including: BMI and midfoot plantar pressures; elevated forefoot pressures as a result of diabetic neuropathy; and sex-differences in regional loading patterns.

CONCLUSIONS

At the level of the literature, we confirmed significant effects of disease status, age, BMI, and sex on regional peak plantar pressures. Researchers and clinicians should be aware that measurements of peak plantar pressure variables obtained from different collection equipment are not directly comparable.

Duration of Type 2 Diabetes is a Predictor of Elevated Plantar Foot Pressure

AIMS

Elevated plantar pressure is considered a significant risk factor for ulceration in diabetes mellitus. The aim of this study was to determine whether duration of diabetes could affect plantar pressure in patients with no known significant comorbidity or foot pathology.

METHODS

Participants with type 2 diabetes, but without known confounding factors that could alter peak pressure, were matched for age, weight, and gender and categorized into 3 groups of diabetes duration: group 1 (1-5 yr), group 2 (6-10 yr), and group 3 (11-15 yr). Plantar pressures were recorded utilizing a two-step protocol at a self-selected speed.

RESULTS

One-way analysis of variance (ANOVA) revealed significant differences in mean peak plantar pressures between the three groups under the 2^nd - 4^th metatarsophalangeal joint (MPJ) region of interest (ROI) (p = 0.012 and p = 0.022, respectively) and left heel (p = 0.049). Also, a significant difference in mean pressure-time integral under the left 2^nd - 4^th MPJ ROI (p = 0.021) and right heel (p = 0.048) was observed. Regression analysis confirmed that mean peak plantar pressures in the first group (but not in the second group) were significantly lower than in the third group (p = 0.005).

CONCLUSIONS

As the duration of diabetes increased, peak plantar pressure increased significantly under the 2^nd - 4^th MPJ ROIs. These findings suggest that clinicians should make more use of pressure mapping technology as part of their clinical management plan in patients with diabetes >10 yr, even if they have no complications or deformities, to preserve functional limbs in this high-risk population.

Quantifying Dynamic Changes in Plantar Pressure Gradient in Diabetics with Peripheral Neuropathy

Diabetic foot ulcers remain one of the most serious complications of diabetes. Peak plantar pressure (PPP) and peak pressure gradient (PPG) during walking have been shown to be associated with the development of diabetic foot ulcers. To gain further insight into the mechanical etiology of diabetic foot ulcers, examination of the pressure gradient angle (PGA) has been recently proposed. The PGA quantifies directional variation or orientation of the pressure gradient during walking and provides a measure of whether pressure gradient patterns are concentrated or dispersed along the plantar surface. We hypothesized that diabetics at risk of foot ulceration would have smaller PGA in key plantar regions, suggesting less movement of the pressure gradient over time. A total of 27 participants were studied, including 19 diabetics with peripheral neuropathy and 8 non-diabetic control subjects. A foot pressure measurement system was used to measure plantar pressures during walking. PPP, PPG, and PGA were calculated for four foot regions – first toe (T1), first metatarsal head (M1), second metatarsal head (M2), and heel (HL). Consistent with prior studies, PPP and PPG were significantly larger in the diabetic group compared with non-diabetic controls in the T1 and M1 regions, but not M2 or HL. For example, PPP was 165% (P = 0.02) and PPG was 214% (P < 0.001) larger in T1. PGA was found to be significantly smaller in the diabetic group in T1 (46%, P = 0.04), suggesting a more concentrated pressure gradient pattern under the toe. The proposed PGA may improve our understanding of the role of pressure gradient on the risk of diabetic foot ulcers.

Variation of plantar pressure in Chinese diabetes mellitus

To investigate dynamic changes in plantar pressure in Chinese diabetes mellitus patients and to provide a basis for further preventing diabetic foot. This is a cross-sectional investigation including 649 Chinese diabetes mellitus patients (diabetes group) and 808 "normal" Chinese persons (nondiabetes group) with normal blood glucose levels. All the subjects provided a complete medical history and underwent a physical examination and a 75-g oral glucose tolerance test. All subjects walked barefoot with their usual gait, and their dynamic plantar forces were measured using the one-step method with a plantar pressure measurement instrument; 5 measurements were performed for each foot. No significant differences were found in age, height, body weight, or body mass index between the two groups. The fasting blood glucose levels, plantar contact time, maximum force, pressure-time integrals and force-time integrals in the diabetes group were significantly higher than those in the nondiabetes group (p < 0.05). However, the maximum pressure was significantly higher in the nondiabetes group than in the diabetes group (p < 0.05). No difference was found in the contact areas between the two groups (p > 0.05). The maximum plantar force distributions were essentially the same, with the highest force found for the medial heel, followed by the medial forefoot and the first toe. The peak plantar pressure was located at the medial forefoot for the nondiabetes group and at the hallucis for the diabetes group. In the diabetes group, the momentum in each plantar region was higher than that in the nondiabetes group; this difference was especially apparent in the heel, the lateral forefoot and the hallucis. The dynamic plantar pressures in diabetic patients differ from those in nondiabetic people with increased maximum force and pressure, a different distribution pattern and significantly increased momentum, which may lead to the formation of foot ulcers.