In-shoe Plantar Pressure Research Articles

Can the Plantar Pressure and Temperature Data Trend Show the Presence of Diabetes? A Comparative Study of a Variety of Machine Learning Techniques

This study aimed to explore the potential of predicting diabetes by analyzing trends in plantar thermal and plantar pressure data, either individually or in combination, using various machine learning techniques. A total of twenty-six participants, comprising thirteen individuals diagnosed with diabetes and thirteen healthy individuals, walked along a 20 m path. In-shoe plantar pressure data were collected and the plantar temperature was measured both immediately before and after the walk. Each participant completed the trial three times, and the average data between the trials were calculated. The research was divided into three experiments: the first evaluated the correlations between the plantar pressure and temperature data; the second focused on predicting diabetes using each data type independently; and the third combined both data types and assessed the effect of such to enhance the predictive accuracy. For the experiments, 20 regression models and 16 classification algorithms were employed, and the performance was evaluated using a five-fold cross-validation strategy. The outcomes of the initial set of experiments indicated that the machine learning models were significant correlations between the thermal data and pressure estimates. This was consistent with the findings from the prior correlation analysis, which showed weak relationships between these two data modalities. However, a shift in focus towards predicting diabetes by aggregating the temperature and pressure data led to encouraging results, demonstrating the effectiveness of this approach in accurately predicting the presence of diabetes. The analysis revealed that, while several classifiers demonstrated reasonable metrics when using standalone variables, the integration of thermal and pressure data significantly improved the predictive accuracy. Specifically, when only plantar pressure data were used, the Logistic Regression model achieved the highest accuracy at 68.75%. Those predictions based solely on temperature data showed the Naive Bayes model as the lead with an accuracy of 87.5%. Notably, the highest accuracy of 93.75% was observed when both the temperature and pressure data were combined, with the Extra Trees Classifier performing the best. These results suggest that combining temperature and pressure data enhances the model’s predictive accuracy. This can indicate the importance of multimodal data integration and their potentials in diabetes prediction.

Influence of Outsole Structures on Foot Loading and Gait Stability

As the downstream products most relevant to the leather industry, leather shoes perform well in the global market. Consumers have put forward high requirements for the comfort and safety of leather shoes in recent years, especially for high heels, whose unique outsole structure often causes foot overloading. The outsole structure varies in ground-contacted mode and heel base size, and plays a decisive role in its function, affecting gait patterns. This study aimed to investigate differences in foot loading and gait stability induced by different outsole structures, at two typical heel heights. Six pairs of customized high heels (3 outsole structures × 2 heel heights) were tested on eighteen healthy females while walking by the Novel Pedar-X in-shoe plantar pressure system. Taking the thick high heels for the intermediate control group, the main effects of the outsole structures and the heel heights, and their interactions on the plantar pressures were analyzed by Two-way repeated ANOVAs. The center of pressure displacements and velocities were calculated throughout the whole stance phase. The results indicated that the whole ground-contacted mode of the outsole displayed better stability in the medial-lateral direction in the early stance phase but may increase the risk of hallux valgus because of the elevated load there. On the contrary, the smaller heel base size exhibited poorer stability in the medial-lateral direction in the early stance phase and would increase forefoot loading. The response of gait characteristics to heel height change is more prominent, which could cause a more vulnerable gait posture. The results could be relevant to improving high-heel functional design, positively motivating the transformation and upgrading of the leather shoe industry.

Associations between static foot posture, dynamic in-shoe plantar foot forces and knee pain in people with medial knee osteoarthritis: A cross-sectional exploratory study

ObjectiveTo investigate relationships between static foot posture, dynamic plantar foot forces and knee pain in people with medial knee osteoarthritis (OA). DesignData from 164 participants with symptomatic, moderate to severe radiographic medial knee OA were analysed. Knee pain was self-reported using a numerical rating scale (NRS; scores 0-10; higher scores worse) and the Knee Injury and Osteoarthritis Outcome Score pain subscale (KOOS; scores 0-100; lower scores worse). Static foot posture was assessed using clinical tests (foot posture index, foot mobility magnitude, navicular drop). Dynamic plantar foot forces (lateral, medial, whole foot, medial-lateral ratio, arch index) were measured using an in-shoe plantar pressure system while walking. Relationships between foot posture and plantar forces (independent variables) and pain (dependent variables) were evaluated using linear regression models, unadjusted and adjusted for sex, walking speed, KL grade, shoe category, and body mass (for dynamic plantar foot forces). ResultsNo measure of static foot posture was associated with any knee pain measure. Higher medial-lateral foot force ratio at midstance, and a higher arch index during overall stance, were weakly associated with higher knee pain on the NRS (regression coefficient=0.69, 95% confidence interval (CI) 0.09 to 1.28) and KOOS (coefficient=3.03, 95% CI 0.71 to 5.35) pain scales, respectively. ConclusionDynamic plantar foot forces, but not static foot posture, were associated with knee pain in people with medial knee OA. However, the amount of pain explained by increases in plantar foot force was small, thus these associations are unlikely to be clinically meaningful.

Comparison of in-shoe plantar pressure between Korean combat boots and running shoes

IntroductionCombat boots are special shoes designed for soldiers to wear during activities in rough terrain, such as long marches or military training. Combat boots have been known to cause high...

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

IntroductionLoss 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. MethodsA 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. ResultsA 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. ConclusionInstrumented 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.

In-Shoe Pressure Measurements in Diabetic Footwear Practice: Success Rate and Facilitators of and Barriers to Implementation.

We aimed to assess the success rate and facilitators of and the barriers to the implementation of in-shoe plantar pressure measurements in footwear practice for people with diabetes at high risk of foot ulceration. Eleven Dutch footwear practices were partly supported in purchasing a pressure measurement system. Over a 2.5-year period, trained shoe technicians evaluated 1030 people with diabetes (range: 13 to 156 across practices). The implementation success and associated facilitators and barriers were evaluated quantitatively using completed measurement forms and pressure measurement data obtained during four monitoring sessions and qualitatively through semi-structured interviews with technicians. Across the 11 practices, the primary target group (people with diabetes and a healed plantar foot ulcer) represented 25-90% of all the patients measured. The results showed that three practices were successful, five moderately successful, and three not successful. The facilitators included support by the company management board, collaboration with a prescribing physician, measurement sessions separate from the outpatient clinic, and a (dedicated) shoe technician experiencing a learning effect. The barriers included investment costs, usability aspects, and limited awareness among shoe technicians. In-shoe plantar pressure measurements can be implemented to a moderate to large degree in diabetic footwear practice. The barriers to and facilitators of implementation are organizational, logistical, financial, or technical, and the barriers are modifiable, supporting future implementation.

Impact of Fatigue on Ergonomic Risk Scores and Foot Kinetics: A Field Study Employing Inertial and In-Shoe Plantar Pressure Measurement Devices.

(1) Background: Occupational fatigue is a primary factor leading to work-related musculoskeletal disorders (WRMSDs). Kinematic and kinetic experimental studies have been able to identify indicators of WRMSD, but research addressing real-world workplace scenarios is lacking. Hence, the authors of this study aimed to assess the influence of physical strain on the Borg CR-10 body map, ergonomic risk scores, and foot pressure in a real-world setting. (2) Methods: Twenty-four participants (seventeen men and seven women) were included in this field study. Inertial measurement units (IMUs) (n = 24) and in-shoe plantar pressure measurements (n = 18) captured the workload of production and office workers at the beginning of their work shift and three hours later, working without any break. In addition to the two 12 min motion capture processes, a Borg CR-10 body map and fatigue visual analog scale (VAS) were applied twice. Kinematic and kinetic data were processed using MATLAB and SPSS software, resulting in scores representing the relative distribution of the Rapid Upper Limb Assessment (RULA) and Computer-Assisted Recording and Long-Term Analysis of Musculoskeletal Load (CUELA), and in-shoe plantar pressure. (3) Results: Significant differences were observed between the two measurement times of physical exertion and fatigue, but not for ergonomic risk scores. Contrary to the hypothesis of the authors, there were no significant differences between the in-shoe plantar pressures. Significant differences were observed between the dominant and non-dominant sides for all kinetic variables. (4) Conclusions: The posture scores of RULA and CUELA and in-shoe plantar pressure side differences were a valuable basis for adapting one-sided requirements in the work process of the workers. Traditional observational methods must be adapted more sensitively to detect kinematic deviations at work. The results of this field study enhance our knowledge about the use and benefits of sensors for ergonomic risk assessments and interventions.

New biomechanical models for cumulative plantar tissue stress assessment in people with diabetes at high risk of foot ulceration

To better understand stress-related foot ulceration in diabetes, the cumulative plantar tissue stress (CPTS) should be quantified accurately, but also feasibly for clinical use. We developed multiple CPTS models with varying complexity and investigated their agreement with the most comprehensive reference model available. We assessed 52 participants with diabetes and high foot ulcer risk for barefoot and in-shoe plantar pressures during overground walking at different speeds, standing, sit-to-stand transitions, and stair walking. Level of these weight-bearing activities along with footwear adherence were objectively measured over seven days. The reference CPTS-model included the pressure–time integrals of each walking stride (barefoot and shod), specified for speed; standing period (barefoot and shod); transition and stair walking stride. We compared four CPTS-models with increasing number of input parameters (models 1–4) with the reference model, using repeated measures ANOVA, Pearson’s correlation and Bland-Altman plots. For the clinically-relevant metatarsal 1 region, calculated CPTS was lower for the four CPTS-models compared to reference (Δ770, Δ466, Δ24 and Δ12 MPa.s/day, respectively). CPTS associated moderately with the reference model for model 1 (r = 0.551) and very strongly for models 2–4 (r ≥ 0.937). Limits of agreement were large for models 1 and 2 (−728;2269 and −302;1233 MPa.s/day), and small for models 3 and 4 (−43;92 and −54;78 MPa.s/day). CPTS in models 3 and 4 best agreed with the reference model, where model 3 required fewer parameters, i.e., pressure–time integrals of each walking stride and standing period while barefoot and shod. These parameters need to be included for accurate and feasible CPTS assessment.

An integrated personalized assistive devices approach to reduce the risk of foot ulcer recurrence in diabetes (DIASSIST): study protocol for a multicenter randomized controlled trial

BackgroundPreventing foot ulcers in people with diabetes can increase quality of life and reduce costs. Despite the availability of various interventions to prevent foot ulcers, recurrence rates remain high. We hypothesize that a multimodal treatment approach incorporating various footwear, self-management, and education interventions that matches an individual person’s needs can reduce the risk of ulcer recurrence with beneficial cost-utility. The aim of this study is to assess the effect on foot ulcer recurrence, footwear adherence, and cost-utility of an integrated personalized assistive devices approach in high-risk people with diabetes.MethodsIn a parallel-group multicenter randomized controlled trial, 126 adult participants with diabetes mellitus type 1 or 2, loss of protective sensation based on the presence of peripheral neuropathy, a healed plantar foot ulcer in the preceding 4 years, and possession of any type of custom-made footwear will be included. Participants will be randomly assigned to either enhanced therapy or usual care. Enhanced therapy consists of usual care and additionally a personalized treatment approach including pressure-optimized custom-made footwear, pressure-optimized custom-made footwear for indoor use, at-home daily foot temperature monitoring, and structured education, which includes motivational interviewing and personalized feedback on adherence and self-care. Participants will be followed for 12 months. Assessments include barefoot and in-shoe plantar pressure measurements; questionnaires concerning quality of life, costs, disease, and self-care knowledge; physical activity and footwear use monitoring; and clinical monitoring for foot ulcer outcomes. The study is powered for 3 primary outcomes: foot ulcer recurrence, footwear adherence, and cost-utility, the primary clinical, patient-related, and health-economic outcome respectively.DiscussionThis is the first study to integrate multiple interventions for ulcer prevention into a personalized state-of-the-art treatment approach and assess their combined efficacy in a randomized controlled trial in people with diabetes at high ulcer risk. Proven effectiveness, usability, and cost-utility will facilitate implementation in healthcare, improve the quality of life of high-risk people with diabetes, and reduce treatment costs.Trial registrationClinicalTrials.gov NCT05236660. Registered on 11 February 2022.

Effective and clinically relevant optimisation of cushioning stiffness to maximise the offloading capacity of diabetic footwear

IntroductionOptimising the cushioning stiffness of diabetic footwear/orthoses can significantly enhance their offloading capacity. This study explores whether optimum cushioning stiffness can be predicted using simple demographic and anthropometric parameters. MethodsSixty-nine adults with diabetes and loss of protective sensation in their feet were recruited for this cross-sectional observational study. In-shoe plantar pressure was measured using Pedar® for a neutral diabetic shoe (baseline) and after adding cushioning footbeds of varying stiffness. The cushioning stiffness that achieved maximum offloading was identified for each participant. The link between optimum cushioning stiffness and plantar loading or demographic/anthropometric parameters was assessed using multinomial regression. ResultsPeople with higher baseline plantar loading required stiffer cushioning materials for maximum offloading. Using sex, age, weight, height, and shoe-size as covariates correctly predicted the cushioning stiffness that minimised peak pressure across the entire foot, or specifically in the metatarsal heads, midfoot and heel regions in 70%, 72%, 83% and 66% of participants respectively. ConclusionsIncreased plantar loading is associated with the need for stiffer cushioning materials for maximum offloading. Patient-specific optimum cushioning stiffness can be predicted using five simple demographic/anthropometric parameters. These results open the way for methods to optimise cushioning stiffness as part of clinical practice.

Evaluation of in-shoe plantar pressure and shear during walking for diabetic foot ulcer prevention.

To investigate reliability and changes of in-shoe plantar pressure and shear during walking at three cadences with two insole designs. This was a precursor to the investigation of plantar loading in people with diabetes for potential foot ulcer prevention. A sensorised insole system, capable of measuring plantar pressure and shear at the heel, fifth metatarsal head (5MH), first metatarsal head (1MH) and hallux, was tested with ten healthy participants during level walking. Reliability was evaluated, using intra-class correlation coefficient (ICC), while varying the cadences and insole types. Percentage changes in pressure and shear relative to values obtained at self-selected cadence with a flat insole design were investigated. Mean±standard deviation of maximum pressure, medial-lateral and anterior-posterior shear of up to 380±24kPa, 46±2kPa and -71±4kPa, respectively, were measured. The ICC in ranges of 0.762-0.973, 0.758-0.987 and 0.800-0.980 were obtained for pressure, anterior-posterior and medial-lateral shear, respectively. Opposite anterior-posterior shear directions between 5MH and 1MH (stretching), and between 1MH and hallux (pinching) were observed for some participants. Increasing cadence increased pressure and anterior-posterior shear (by up to +77%) but reduced medial-lateral shear at the heel and hallux (by up to -34%). Slower cadence increased anterior-posterior shear (+114%) but decreased medial-lateral shear (-46%) at the hallux. The use of a flexible contoured insole resulted in pressure reduction at the heel and 5MH but an increase in anterior-posterior shear at the heel (+69%) and hallux (+75%). The insole system demonstrated good reliability and is comparable to reported pressure-only systems. Pressure measurements were sensitive to changes in cadence and insole designs in ways that were consistent with the literature. However, our plantar shear showed localised shear changes with cadences and insoles for the first time, as well as stretching and pinching effects on plantar tissue. This opens new possibilities to investigate plantar tissue viability, loading characteristics and orthotic designs aimed towards foot ulcer prevention.

Innovative single-sensor, in-shoe pressure and temperature monitoring device: A static laboratory validation study

BackgroundTo perform laboratory static validation of pressures from an innovative, single-sensor pressure and temperature monitoring device for the early detection of complications in the high-risk foot. Research questionCan an innovative, newly developed, in-shoe pressure and temperature measuring device, detect and measure the in-shoe peak plantar pressures and skin temperature as accurately as the reference standard? MethodsA pressure generating rig, the Tekscan™ Equilibration ‘bladder calibrator’, was used to produce a known force, against the gold standard, FScan™ in-shoe pressure mapping system by Tekscan™ and a newly developed prototype. The F-scan® system was used to record the pressure readings and establish a baseline for the readings recorded utilising the prototype. A total of 20 pressure values were recorded with 100 samples each. ResultsExploratory data analysis was conducted to gain insights and analyse the prototype's behaviour at different pressure points. Pre-processing and data cleaning were also performed to remove any anomalies. Support Vector Regressor with a polynomial kernel and Grid-Search algorithm was used to fit the recorded data curve. The best combination of parameters had a Mean Squared Error of 2.59 and a Root Mean Squared Error of 1.61. A simple linear equation was used to convert raw readings to pressure values. SignificanceThe results of this study conclude that the pressure measurements taken with the prototype are congruent to the gold standard, F-scan® in-shoe system. This confirms that the prototype is a valid device that can be used safely as a low-cost alternative to current costly commercial in-shoe pressure mapping devices.

Clinical and biomechanics effects of modified Helal osteotomy with screw fixation in forefoot reconstruction.

The object of this study was to assess the efficacy of Helal metatarsal osteotomy with screw fixation in patients with hammertoe deformities. Thirty-five patients (66 feet, 66 metatarsals) with hammertoe deformity underwent Helal osteotomy with screw fixation after first ray reconstruction. Pre- and postoperative AOFAS scale results, podobarometry (in-shoe plantar pressure), and X-ray (angular) parameters were analyzed. The patients were examined before the operation and two, six, and 24 months postoperatively. The average AOFAS score was 59 (± 2.4) preoperatively and 96 (± 1.2) in 12 months after the operations. Pressure under the second and third metatarsal heads was decreased from 396 (± 52.3) kPa preoperatively to 240 (± 22.3) kPa 12 months postoperatively. Lateral subluxation of the second and third toes before the operation was observed in 62 (94%) feet, average metatarsophalangeal angle was 28.1 (± 3.3) degrees. While it was not found in any case 12 months after operation, in four (6.1%) feet, it became recurrent 24 months postoperatively; the average metatarsophalangeal angle was 5° (± 0.6). Helal osteotomy with screw fixation demonstrated good-to-excellent results in 24 months postoperatively. It allows for a three-dimension lesser rays reconstruction: shortening, elevating, and lateral or medial displacement of the metatarsal head.

Effects of Rearfoot Eversion on Foot Plantar Pressure and Spatiotemporal Gait Parameters in Adolescent Athletes

Background: Foot malalignment can augment the risk of lower-extremity injuries and lead to musculoskeletal disorders. This study aimed to clarify the contribution of rearfoot alignment to plantar pressure distribution and spatiotemporal parameters during gait in healthy adolescent athletes. Methods: This retrospective study included 39 adolescent athletes who were divided into the rearfoot eversion and control groups according to a leg heel angle of 7°. A total of 78 legs were analyzed (45 and 33 legs in the rearfoot eversion [women, 53.3%] and control groups [women, 48.5%], respectively). Gait was assessed using an in-shoe plantar pressure measuring system and a wearable inertial sensor. Results: The foot plantar pressure distribution in the hallux was higher in the rearfoot eversion group than that in the control group (p = 0.034). Spatiotemporal parameters showed that the foot pitch angle at heel strike was significantly larger in the rearfoot eversion group than that in the control group (24.5° vs. 21.7°; p = 0.015). Total sagittal range of motion of the ankle during the stance phase of gait was significantly larger in the rearfoot eversion group than that in the control group (102.5 ± 7.1° vs. 95.6 ± 15.8°; p = 0.020). Logistic regression analysis revealed that plantar pressure at the hallux and medial heel and foot pitch angle at heel strike were significantly associated with rearfoot eversion. Conclusions: Our findings suggest that rearfoot eversion affects the gait patterns of adolescent athletes. Notably, leg heel angle assessment, which is a simple and quick procedure, should be considered as an alternative screening tool for estimating plantar pressure and spatiotemporal gait parameters to prevent sports-related and overuse injuries in adolescent athletes.

In-shoe plantar pressure depends on walking speed and type of weight-bearing activity in people with diabetes at high risk of foot ulceration

BackgroundIn evaluating therapeutic footwear, in-shoe plantar pressure is usually obtained during mid-gait steps at self-selected walking speed in a laboratory setting. However, this may not accurately represent plantar pressures or indicate the cumulative stress experienced in daily life. We investigated the effects of walking speed and different weight-bearing activities on in-shoe plantar pressure in people with diabetes at high risk of ulceration. MethodsIn a cross-sectional study including 30 participants we compared in-shoe plantar pressures between three standardized walking speeds (0.8, 0.6 and 0.4 m/s) and between walking at self-selected speed and eight other weight-bearing activities (3 components of the Timed Up and Go test, accelerating, decelerating, stair ascending and descending, and standing). Mean forefoot regional peak plantar pressure and pressure-time integral were statistically assessed per foot using linear mixed models (α < 0.05) with Holm-Bonferroni correction. FindingsWith increasing walking speed, peak pressures increased and pressure-time integrals decreased (P ≤ 0.014). Peak pressures during standing, decelerating, stair ascending and Timed Up and Go test were lower (P ≤ 0.001), and with other activities not different to walking at self-selected speed. Pressure-time integrals during stair ascending and descending were higher (P ≤ 0.001), during standing lower (P ≤ 0.009), and with other activities not different to walking at self-selected speed. InterpretationIn-shoe plantar pressure depends on walking speed and type of weight-bearing activity. Only measuring pressures to evaluate footwear at self-selected walking speed in a laboratory setting may not accurately represent the stress on the foot in daily life of the high-risk patient; a more comprehensive assessment is suggested.

FABRICATION OF A DIGITAL PLANTAR PRESSURE ESTIMATING DEVICE WITH INTERNET OF THINGS ABILITY

Digitally estimating the magnitude of the Plantar Pressures (PP) of the foot is an important aspect in the biomechanical management of diabetic foot and is not yet adopted in our clime and many low income countries mostly due to high cost and complexity of existing designs, as well as poor awareness. This study aimed to produce a cheaper, easier to use and internet of things compliant digital plantar pressure estimating device (DPPE) which should be able to detect, estimate and output in-shoe plantar pressure distribution. 10 Force Sensitive Resistor (FSR) were anatomically spread across an ambipedal insole. ESP8266 board was utilized as the microcontroller. Web applications were designed to ensure a smooth communication between the sensors, the microcontroller, the internet and the display units (Computers and Phones). The device achieved ambipedal fitting, Wi-Fi to internet signal transmissions were successful, and the sensors ability to detect and estimate pressure was achieved. The DPPE as produced in this study can help in achieving digital assessment of the PP estimation and its distribution on the foot for clinical evaluations, hence, it is an important tool in the clinical assessment of the DF managements. Use of WiFi as a mode of data transmission is ideal in a post-COVID world of ours as it supports virtual communication.

Reliability of F-Scan® in-shoe plantar pressure measurements in people with diabetes at risk of developing foot ulcers

BackgroundThe provision of therapeutic footwear, to prevent the development of diabetic foot ulcers by re-distributing high peak plantar pressure is frequently prescribed for patients with diabetes. Areas of interest (ROI) are identified by placing boxes on the visualised pressure movie. The aims were to evaluate the inter-reliability of the placements of seven ROI boxes and to explore how the box placement affected peak pressure in the seven ROIs. MethodsPlantar pressure movies from 20 of a total of 40 movies were selected for the analysis. Boxes were placed at ROIs, the heel, the lateral midfoot, the metatarsal phalangeal heads (5, 3–4, 2 and 1) and the hallux. The box placements were registered for the left vertical position (L) and the top horizontal position (T) for each of the ROIs, based on registrations by two certified prosthetists and orthotists. FindingsThe inter correlation coefficient of the placement of the boxes ranged from 1.00 to 0.12 (heel_L and metatarsal phalangeal head 2_L respectively). Of the 14 positions of the boxes; four were excellent, four were good, two were moderate and four were poor. No significant differences in the mean peak pressure corresponding to the box placements were found between the CPOs. InterpretationThe inter-reliability of eight of the 14 registered placements, made by prosthetists and orthotists, of the boxes in Scan® was good to excellent. A variation of 1.00–0.12 was present. Despite the variation, no significant differences in the corresponding mean peak pressure between prosthetists and orthotists was found.

Biosignals by In-Shoe Plantar Pressure Sensors on Different Hardness Mats during Running: A Cross-Over Study

Although the effects of running on plantar pressures have been detailed on several surfaces with different hardness, there is a lack of studies assessing the mechanical behavior analysis by in-shoe plantar pressure sensors on different hardness mats during running. The aim of the present study was to determine in-shoe maximum forces and peak plantar pressures on mats with different hardness, such as hard, soft and air chamber mats, during running. A cross-over study was carried out including 36 amateur runners from a sport center. The maximum force and peak pressures of the foot plantar region were analyzed on three different mat hardnesses —soft and hard polyurethane foam mats and air chamber mats—by in-shoe instrumented insoles. Running on soft polyurethane foam mats presented reduced maximum forces in the whole plantar region and mainly peak pressures in the anterior part of the foot plantar region, such as the toes and first to fourth metatarsal heads, compared to hard polyurethane foam and air chamber mats. The peak pressure in the fifth metatarsal head was specifically reduced during running on soft compared to hard polyurethane foam mats, and running on these soft mats decreased calcaneus peak pressures compared to running on air chamber mats. Running on air chamber mats increased peak plantar pressures in the first metatarsal head compared to running on hard polyurethane foam mats. The mechanical behavior of mats of different hardness could be used to adjust the degree of impact on plantar pressures to determine the most appropriate materials and hardness for running.

Graded stiffness offloading insoles better redistribute heel plantar pressure to protect the diabetic neuropathic foot

BackgroundDiabetic heel ulceration is a common, detrimental, and costly complication of diabetes. This study investigates a novel “graded-stiffness” offloading method, which consists of a heel support with increasing levels of stiffness materials to better redistribute plantar pressure for heel ulcer prevention and treatment. Research questionIs the novel “graded-stiffness” solution better able to redistribute heel pressure and reduce focal stress concentration areas of the heel? MethodsTwenty healthy young men walked with four, 3D-printed, insole configurations. The configurations included the “graded-stiffness” insoles with and without an offloading hole under the heel tissue at risk for ulcerations and two conventional offloading supports of flat insoles with no offloading and simple holed offloading insoles. In-shoe plantar pressure was measured using the Pedar-X system. Peak pressure and pressure dose were measured at three heel regions: offloaded region, perimeter of offloaded region, and periphery region. ResultsThe simple offloading configuration reduced pressure at the offloaded region; however, pressure at the perimeter of the offloading region significantly increased. With respect to ANOVA, the “graded-stiffness” offloading configurations were more effective than existing tested solutions in reducing and redistributing heel peak pressure and pressure dose, considering all heel regions. SignificanceThe “graded-stiffness” offloading solution demonstrated a novel flexible and customized solution that can be manufactured on-demand through a precise selection of the graded-stiffness offloading location and material properties to fit the shape and size of the ulcer. This study is a follow-up in-vivo pilot study, in a healthy population group, to our previous computation modeling work that reported the efficiency of the “graded-stiffness” configuration, and which emphasizes its potential for streamlining and optimizing the prevention and treatment of diabetic heel ulcers.

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

BackgroundFoot 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.MethodsThis 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.DiscussionThis 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 registrationAustralian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12620000699965p. Registered on June 23, 2020