A state-of-the-art review of foot pressure

Using Flexible-Printed Piezoelectric Sensor Arrays to Measure Plantar Pressure during Walking for Sarcopenia Screening

Sarcopenia is an age-related syndrome characterized by the loss of skeletal muscle mass and function. Community screening, commonly used in early diagnosis, usually lacks features such as real-time monitoring, low cost, and convenience. This study introduces a promising approach to sarcopenia screening by dynamic plantar pressure monitoring. We propose a wearable flexible-printed piezoelectric sensing array incorporating barium titanate thin films. Utilizing a flexible printer, we fabricate the array with enhanced compressive strength and measurement range. Signal conversion circuits convert charge signals of the sensors into voltage signals, which are transmitted to a mobile phone via Bluetooth after processing. Through cyclic loading, we obtain the average voltage sensitivity (4.844 mV/kPa) of the sensing array. During a 6 m walk, the dynamic plantar pressure features of 51 recruited participants are extracted, including peak pressures for both sarcopenic and control participants before and after weight calibration. Statistical analysis discerns feature significance between groups, and five machine learning models are employed to screen for sarcopenia with the collected features. The results show that the features of dynamic plantar pressure have great potential in early screening of sarcopenia, and the Support Vector Machine model after feature selection achieves a high accuracy of 93.65%. By combining wearable sensors with machine learning techniques, this study aims to provide more convenient and effective sarcopenia screening methods for the elderly.

The Effect of First Metatarsal Shortening and Sagittal Displacement on Forefoot Pressure in Minimally Invasive Hallux Valgus Correction

BACKGROUND

Minimally invasive (MIS) treatment of hallux valgus (HV) deformity is increasing in popularity. A 2-mm diameter burr is used to create a distal first metatarsal osteotomy prior to capital fragment translation and fixation. The metatarsal will shorten by the burr's diameter (2 mm). Plantar or dorsal capital fragment displacement may also cause load transference and possibly transfer metatarsalgia. The purpose of this study is to examine the effect of MIS HV on forefoot loading mechanics with respect to metatarsal shortening and sagittal plane displacement.

METHODS

Four lower-limb cadaveric specimens were studied. A pedobarography pressure-sensing mat was used to record forefoot plantar pressure in a controlled weight-bearing stance position. Control and postosteotomy measurements were obtained with the capital fragment fixated in 3 possible positions: 0 mm, 5 mm dorsal, and 5 mm plantar displacement. Pedobarography data yielded pressure data within measurable graphical depictions. Raw mean contact pressure measurements were taken under the first and fourth metatarsal heads to establish medial and lateral forefoot loading pressure ratios. An a priori power analysis was performed based on previous peer-reviewed pedobarographic data, and our study was adequately powered.

RESULTS

Around 40 measurements were recorded, and ratios of medial-to-lateral forefoot loading were constructed. Medial forefoot pressure control versus 0 mm displacement, and control versus dorsal displacement were not found to be statistically significant (p = 0.525, p = 0.55, respectively). Medial pressure significantly increased when comparing control versus plantar displacement (P = .006). Lateral pressure significantly increased with dorsal displacement of the osteotomy (P = .013).

CONCLUSION

Our study found that MIS HV correction did not cause an increase in lateral forefoot pressure loading when sagittal plane displacements were controlled. Plantar displacement increased medial loading, and dorsal displacement increased lateral loading. It may be valuable for surgeons to consider metatarsal head position postosteotomy, as a decrease in medial loading and subsequent increase in lateral loading may lead to lateral forefoot pain and transfer metatarsalgia.

LEVELS OF EVIDENCE

IV.

Custom orthotic design by integrating 3D scanning and subject-specific FE modelling workflow

The finite element (FE) foot model can help estimate pathomechanics and improve the customized foot orthoses design. However, the procedure of developing FE models can be time-consuming and costly. This study aimed to develop a subject-specific scaled foot modelling workflow for the foot orthoses design based on the scanned foot surface data. Six participants (twelve feet) were collected for the foot finite element modelling. The subject-specific surface-based finite element model (SFEM) was established by incorporating the scanned foot surface and scaled foot bone geometries. The geometric deviations between the scaled and the scanned foot surfaces were calculated. The SFEM model was adopted to predict barefoot and foot-orthosis interface pressures. The averaged distances between the scaled and scanned foot surfaces were 0.23 ± 0.09 mm. There was no significant difference for the hallux, medial forefoot, middle forefoot, midfoot, medial hindfoot, and lateral hindfoot, except for the lateral forefoot region (p = 0.045). The SFEM model evaluated slightly higher foot-orthoses interface pressure values than measured, with a maximum deviation of 7.1%. These results indicated that the SFEM technique could predict the barefoot and foot-orthoses interface pressure, which has the potential to expedite the process of orthotic design and optimization.

AI-Assisted Insole Sensing System for Multifunctional Plantar-Healthcare Applications

The pervasive global issue of population aging has led to a growing demand for health monitoring, while the advent of electronic wearable devices has greatly alleviated the strain on the industry. However, these devices come with inherent limitations, such as electromagnetic radiation, complex structures, and high prices. Herein, a Solaris silicone rubber-integrated PMMA polymer optical fiber (S-POF) intelligent insole sensing system has been developed for remote, portable, cost-effective, and real-time gait monitoring. The system is capable of sensitively converting the pressure of key points on the sole into changes in light intensity with correlation coefficients of 0.995, 0.952, and 0.910. The S-POF sensing structure demonstrates excellent durability with a 4.8% variation in output after 10,000 cycles and provides stable feedback for bending angles. It also exhibits water resistance and temperature resistance within a certain range. Its multichannel multiplexing framework allows a smartphone to monitor multiple S-POF channels simultaneously, meeting the requirements of convenience for daily care. Also, the system can efficiently and accurately provide parameters such as pressure, step cadence, and pressure distribution, enabling the analysis of gait phases and patterns with errors of only 4.16% and 6.25% for the stance phase (STP) and the swing phase (SWP), respectively. Likewise, after comparing various AI models, an S-POF channel-based gait pattern recognition technique has been proposed with a high accuracy of up to 96.87%. Such experimental results demonstrate that the system is promising to further promote the development of rehabilitation and healthcare.

Influence of motor capacity of the lower extremity and mobility performance on foot plantar pressures in community-dwelling older women

Objectives

To investigate the associations of motor capacity of the lower extremity and mobility performance in daily physical activities with peak foot plantar pressures during walking among older women.

Methods

Using the data collected among 58 community-dwelling older women (68.66 ± 3.85 years), Pearson correlation and multiple linear regression analyses were performed to analyze the associations of motor capacity of the lower extremity (the 30-s chair stand test, the timed one-leg stance with eyes closed, and the Fugl-Meyer assessment of lower extremity), mobility performance in daily physical activities (the average minutes of moderate to vigorous physical activity every day and the metabolic equivalents), and foot plantar pressures (peak force and peak pressure) with the age and body fat percentage as covariates.

Results

(1) The motor capacity of the lower extremity has higher explanatory power for peak foot plantar pressures compared with the mobility performance in daily physical activities. (2) Higher body fat percentage was positively associated with peak force and pressure, while a lower score on the Fugl-Meyer assessment of lower extremity was negatively associated with both of them. (3) The metabolic equivalents were positively associated with the peak force, while the 30-s chair stand test was negatively associated with it.

Conclusions

Mobility performance in daily physical activities can be significant predictors for peak foot plantar pressures among older women. The significant predictor variables include the Fugl-Meyer assessment of lower extremity, the 30-s chair stand test, and metabolic equivalents.

Accuracy of unilateral and bilateral gait assessment using a mobile gait analysis system at different walking speeds

BACKGROUND

Previous research on the accuracy of mobile measurement systems has focused on parameters related to the whole gait cycle. Specifically, bilateral gait characteristics were primarily used as outcome measures.

RESEARCH QUESTION

How accurate are unilateral gait characteristics detected using a mobile system at various fixed walking speeds?

METHODS

Gait analysis during treadmill walking at velocities (VEL) of 2.5 (v1), 4.5 (v2) and 6.5 km/h (v3) was performed in a population of 47 healthy young adults, consisting of 27 females (age: 23 ± 2 years, BMI: 21.4 ± 2.2 kg/m²) and 20 males (age: 22 ± 1 years, BMI: 23.3 ± 3.4 kg/m²). Spatiotemporal gait data were simultaneously determined using an instrumented treadmill (gaitway 3D) and a mobile gait analysis system (RehaGait). Besides VEL, bilateral (stride length [SL], cadence [CAD]) and unilateral (contact duration [CON], single [SS] and double support duration [DS]) outcomes were validated.

RESULTS

Across the three VEL investigated, the correlations between both measurement systems were almost perfect in SL and CAD (r > 0.97). In addition, SL significantly differed (p < 0.01) with moderate to large effects, whereby the root mean squared error (RMSE) did not exceed 1.8 cm. RMSE in CAD was not higher than 0.33 spm and statistically significant differences were only present at v1 (d = 0.63). DS was the most erroneous unilateral parameter with values for %RMSE ranging from 9% at v1 to 14% at v3. In CON and SS %RMSE was in a magnitude of 2-4% across all VEL. Furthermore, VEL affected measurement accuracy in unilateral outcomes with moderate to large effects (F (2, 45) > 6.0, p < 0.01, ηp2 > 0.11) with consistently higher differences at lower velocities.

SIGNIFICANCE

Based on the results presented the validity of the mobile gait analysis system investigated to detect gait asymmetries must be questioned.

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.

Foot Plantar Pressure Abnormalities in Near Adulthood Patients with Type 1 Diabetes

Increased ulcer risk diminishes the quality of life in diabetes. This study assessed abnormalities in foot plantar pressure distribution in adolescents with T1D to detect early signs of ulcer risk. A total of 102 T1D patients, without diabetic neuropathy, were included (mean age 17.8 years, mean diabetes duration 7.4 year). Pedography was captured using Novel emed. Data from the study group were compared with reference data. The study revealed a statistically significant reduced foot contact area in both feet in the entire foot and under the head of the fifth metatarsal bone and the second toe. In both feet, the peak pressure was increased under the entire foot, hindfoot, midfoot, first metatarsal head, big toe, and second toe. There was no statistically significant difference in peak pressure. The mean plantar pressure rating was statistically significantly increased in both feet across the entire sole, in the hindfoot, midfoot, and first metatarsal head. T1D patients of age near adulthood without neuropathy have increased values in mean pressure and reduced contact area, pointing to the need of monitoring and preventive measures. These results point to the need of further research and analysis which should include various risk factor such as foot anatomy, body posture, or certain metabolic factors.

A Review of Piezoelectric Footwear Energy Harvesters: Principles, Methods, and Applications

Over the last couple of decades, numerous piezoelectric footwear energy harvesters (PFEHs) have been reported in the literature. This paper reviews the principles, methods, and applications of PFEH technologies. First, the popular piezoelectric materials used and their properties for PEEHs are summarized. Then, the force interaction with the ground and dynamic energy distribution on the footprint as well as accelerations are analyzed and summarized to provide the baseline, constraints, potential, and limitations for PFEH design. Furthermore, the energy flow from human walking to the usable energy by the PFEHs and the methods to improve the energy conversion efficiency are presented. The energy flow is divided into four processing steps: (i) how to capture mechanical energy into a deformed footwear, (ii) how to transfer the elastic energy from a deformed shoes into piezoelectric material, (iii) how to convert elastic deformation energy of piezoelectric materials to electrical energy in the piezoelectric structure, and (iv) how to deliver the generated electric energy in piezoelectric structure to external resistive loads or electrical circuits. Moreover, the major PFEH structures and working mechanisms on how the PFEHs capture mechanical energy and convert to electrical energy from human walking are summarized. Those piezoelectric structures for capturing mechanical energy from human walking are also reviewed and classified into four categories: flat plate, curved, cantilever, and flextensional structures. The fundamentals of piezoelectric energy harvesters, the configurations and mechanisms of the PFEHs, as well as the generated power, etc., are discussed and compared. The advantages and disadvantages of typical PFEHs are addressed. The power outputs of PFEHs vary in ranging from nanowatts to tens of milliwatts. Finally, applications and future perspectives are summarized and discussed.

Association between toe pressure strength in the standing position and postural control capability in healthy adults

BACKGROUND

A method has been developed to assess toe pressure strength in the standing position, taking into account concerns about toe grip strength.

RESEARCH QUESTION

Which is more associated to postural control capability, the conventional toe grip strength or the newly devised toe pressure strength in the standing position, which is close to the actual movement?

METHODS

This study is a cross-sectional study. This study included 67 healthy adults (mean age, 19 ± 1 years; 64% male). The postural control capability was measured using the center-of-pressure shift distance in the anterior-posterior axis. Toe pressure strength in the standing position was assessed using a toe pressure measuring device to evaluate the force of pressure on the floor surface by all toes. During measurement, care is taken to ensure that the toes do not flex. However, toe grip strength in the sitting position was measured using muscle strength for toe flexion in a conventional manner. Statistical analysis was conducted by performing a correlation analysis between each of the measured items. Additionally, multiple regression analysis was used to examine the functions associated with postural control capability.

RESULT

Pearson's correlation analysis revealed that the postural control capability was correlated with toe pressure strength in the standing position (r = 0.36, p = 0.003). Multiple regression analysis demonstrated that only toe pressure strength in the standing position was significantly associated with the postural control capability, even after adjusting for covariates (standard regression coefficient: 0.42, p = 0.005).

SIGNIFICANCE

The results of this study indicated that toe pressure strength in the standing position was more strongly associated with the postural control capability in healthy adults than toe grip strength in the sitting position. It has been suggested that a rehabilitation program for toe pressure strength in the standing position would help improve postural control capability.

Functional gait analysis reveals insufficient hindfoot compensation for varus and valgus osteoarthritis of the knee

PURPOSE

The hindfoot is believed to compensate varus and valgus deformities of the knee by eversion and inversion movements. But these mechanisms were merely found in static radiologic measurements. The aim of this study was, therefore, to assess dynamic foot posture during gait using pressure-sensitive wireless insoles in patients with osteoarthritis of the knee and frontal knee deformities.

METHODS

Patients with osteoarthritis of the knee were prospectively included in this study. Patients were clinically and radiologically (mechanical tibiofemoral angle (mTFA), hindfoot alignment view angle (HAVA), and talar tilt (TT)) exa mined. Gait line analysis was conducted using pressure-sensitive digital shoe insoles.

RESULTS

Eighty-two patients (varus n = 52, valgus n = 30) were included in this prospective clinical study. Radiologically, the mTFA significantly correlated with the HAVA (cor = -0.72, p < 0.001) and with the TT (Pearson's cor = 0.32, p < 0.006). Gait analysis revealed that the gait lines in varus knee osteoarthritis were lateralized, despite the hindfoot valgus. In valgus knee osteoarthritis, gait lines were medialized, although the hindfoot compensated by varization.

CONCLUSIONS

Functional dynamic gait analysis could demonstrate that the hindfoot is not able to sufficiently compensate for frontal malalignments of the knee joint, contrary to static radiologic findings. This led to a narrowing of the joint space of the ankle medially in varus and laterally in valgus knee osteoarthritis.

Benchmarking the Effects on Human-Exoskeleton Interaction of Trajectory, Admittance and EMG-Triggered Exoskeleton Movement Control

Nowadays, robotic technology for gait training is becoming a common tool in rehabilitation hospitals. However, its effectiveness is still controversial. Traditional control strategies do not adequately integrate human intention and interaction and little is known regarding the impact of exoskeleton control strategies on muscle coordination, physical effort, and user acceptance. In this article, we benchmarked three types of exoskeleton control strategies in a sample of seven healthy volunteers: trajectory assistance (TC), compliant assistance (AC), and compliant assistance with EMG-Onset stepping control (OC), which allows the user to decide when to take a step during the walking cycle. This exploratory study was conducted within the EUROBENCH project facility. Experimental procedures and data analysis were conducted following EUROBENCH's protocols. Specifically, exoskeleton kinematics, muscle activation, heart and breathing rates, skin conductance, as well as user-perceived effort were analyzed. Our results show that the OC controller showed robust performance in detecting stepping intention even using a corrupt EMG acquisition channel. The AC and OC controllers resulted in similar kinematic alterations compared to the TC controller. Muscle synergies remained similar to the synergies found in the literature, although some changes in muscle contribution were found, as well as an overall increase in agonist-antagonist co-contraction. The OC condition led to the decreased mean duration of activation of synergies. These differences were not reflected in the overall physiological impact of walking or subjective perception. We conclude that, although the AC and OC walking conditions allowed the users to modulate their walking pattern, the application of these two controllers did not translate into significant changes in the overall physiological cost of walking nor the perceived experience of use. Nonetheless, results suggest that both AC and OC controllers are potentially interesting approaches that can be explored as gait rehabilitation tools. Furthermore, the INTENTION project is, to our knowledge, the first study to benchmark the effects on human-exoskeleton interaction of three different exoskeleton controllers, including a new EMG-based controller designed by us and never tested in previous studies, which has made it possible to provide valuable third-party feedback on the use of the EUROBENCH facility and testbed, enriching the apprenticeship of the project consortium and contributing to the scientific community.

Deep Neural Network for the Detections of Fall and Physical Activities Using Foot Pressures and Inertial Sensing

Fall detection and physical activity (PA) classification are important health maintenance issues for the elderly and people with mobility dysfunctions. The literature review showed that most studies concerning fall detection and PA classification addressed these issues individually, and many were based on inertial sensing from the trunk and upper extremities. While shoes are common footwear in daily off-bed activities, most of the aforementioned studies did not focus much on shoe-based measurements. In this paper, we propose a novel footwear approach to detect falls and classify various types of PAs based on a convolutional neural network and recurrent neural network hybrid. The footwear-based detections using deep-learning technology were demonstrated to be efficient based on the data collected from 32 participants, each performing simulated falls and various types of PAs: fall detection with inertial measures had a higher F1-score than detection using foot pressures; the detections of dynamic PAs (jump, jog, walks) had higher F1-scores while using inertial measures, whereas the detections of static PAs (sit, stand) had higher F1-scores while using foot pressures; the combination of foot pressures and inertial measures was most efficient in detecting fall, static, and dynamic PAs.

Análisis de la presión plantar durante la carrera en el sitio en diferentes superficies

El objetivo de este trabajo es evaluar en 36 corredores aficionados, la fuerza y las presiones del pie sobre tres superficies comúnmente empleadas para el entrenamiento de la carrera en el sitio (césped artificial, suelo técnico de caucho y trampolín plano). Los valores de fuerza y presión se registraron mediante plantillas instrumentadas (Gebiomized® Munster, Germany). Se obtuvieron los siguientes parámetros: Fuerza máxima (N) y picos de presión (N/cm2) en 6 zonas específicas del pie.   Según los resultados, la fuerza máxima ejercida por el pie dominante en césped artificial (657 N) y en suelo técnico de caucho (692,5 N) fue significativamente superior al registrado sobre el trampolín (262 N). Respecto a la presión, la mayor parte de la presión ejercida por el pie en superficies duras (césped artificial y suelo técnico de caucho), se observó en las cabezas de los metatarsianos, mientras que en el trampolín la presión se repartió entre estas y el calcáneo.

The influence of partial weight bearing on plantar peak forces using three different types of postoperative shoes

BACKGROUND

Therapeutic shoes and partial weight bearing regimes are used after foot surgery to prevent the operated region from excessive load. It remains unclear to which extent partial weight bearing reduces the plantar peak forces. Therefore, we investigated the correlation of weight bearing and plantar peak forces in commonly used therapeutic shoes.

METHODS

Three different weight bearing regimes (20 kg, 40 kg, full weight) were investigated in 20 healthy volunteers. Sensor insoles were used to measure peak forces of the forefoot, midfoot, heel and the complete foot using four kind of shoes (bandage shoe, forefoot relief shoe, short walker and standard sneaker). Peak forces were compared between shoes using one-way ANOVA. The influence of partial weight bearing relative to the peak forces was examined by linear regression analysis.

RESULTS

All therapeutic shoes reduced significantly peak forces of the fore- and midfoot when compared to the reference shoe; the largest reduction was achieved by the forefoot relief shoe (-70 % at forefoot). Weight load and the resulting peak force showed a positive linear correlation for all regions and shoe types. Partial weight bearing significantly reduced the forefoot's force ratio compared to full weight bearing for all shoes except the forefoot relief shoe.

CONCLUSIONS

Partial weight bearing is a strong instrument to reduce plantar peak forces of the forefoot, additionally to the proven offloading effect of therapeutic shoes.

Impact of Sex and Velocity on Plantar Pressure Distribution during Gait: A Cross-Sectional Study Using an Instrumented Pressure-Sensitive Walkway

In-shoe systems and pressure plates are used to assess plantar pressure during gait, but additional tools are employed to evaluate other gait parameters. The GAITRite® system is a clinical gait evaluation tool. Extensive literature is available for spatiotemporal parameters, but it is scarce for relative plantar pressure data. Therefore, we investigated whether, when controlling for age, the GAITRite® system is able to distinguish the effects of walking velocity on plantar pressure parameters in six plantar regions in a large sample of adults. Participants (83 women and 87 men, aged 18−85 years) walked at three self-selected velocities (slow, preferred, fast) on a 6-m long GAITRite® walkway. Relative peak pressure, pressure-time integral, peak time and contact area were computed for six zones (lateral and medial heel, mid- and forefoot). The impact of age (covariate), sex, side, velocity, pressure zone and their interactions on pressure variables was evaluated. Velocity affected peak pressure, pressure-time integral, peak time and contact area (p < 0.001). With increasing self-selected gait velocity, medial forefoot peak pressure and pressure-time integral increased (p < 0.001), while heel and lateral forefoot regions displayed a nonlinear plantar pressure evolution. These results suggest lower (heel strike) or more equally distributed (push-off) loads at preferred gait velocity.

Recent Progress in Flexible Pressure Sensor Arrays

Flexible pressure sensors that can maintain their pressure sensing ability with arbitrary deformation play an essential role in a wide range of applications, such as aerospace, prosthetics, robotics, healthcare, human–machine interfaces, and electronic skin. Flexible pressure sensors with diverse conversion principles and structural designs have been extensively studied. At present, with the development of 5G and the Internet of Things, there is a huge demand for flexible pressure sensor arrays with high resolution and sensitivity. Herein, we present a brief description of the present flexible pressure sensor arrays with different transduction mechanisms from design to fabrication. Next, we discuss the latest progress of flexible pressure sensor arrays for applications in human–machine interfaces, healthcare, and aerospace. These arrays can monitor the spatial pressure and map the trajectory with high resolution and rapid response beyond human perception. Finally, the outlook of the future and the existing problems of pressure sensor arrays are presented.

Foot contact forces can be used to personalize a wearable robot during human walking

Individuals with below-knee amputation (BKA) experience increased physical effort when walking, and the use of a robotic ankle-foot prosthesis (AFP) can reduce such effort. The walking effort could be further reduced if the robot is personalized to the wearer using human-in-the-loop (HIL) optimization of wearable robot parameters. The conventional physiological measurement, however, requires a long estimation time, hampering real-time optimization due to the limited experimental time budget. This study hypothesized that a function of foot contact force, the symmetric foot force-time integral (FFTI), could be used as a cost function for HIL optimization to rapidly estimate the physical effort of walking. We found that the new cost function presents a reasonable correlation with measured metabolic cost. When we employed the new cost function in HIL ankle-foot prosthesis stiffness parameter optimization, 8 individuals with simulated amputation reduced their metabolic cost of walking, greater than 15% (p < 0.02), compared to the weight-based and control-off conditions. The symmetry cost using the FFTI percentage was lower for the optimal condition, compared to all other conditions (p < 0.05). This study suggests that foot force-time integral symmetry using foot pressure sensors can be used as a cost function when optimizing a wearable robot parameter.

Polymer Optical Fiber Plantar Pressure Sensors: Design and Validation

The proper measurement of plantar pressure during gait is critical for the clinical diagnosis of foot problems. Force platforms and wearable devices have been developed to study gait patterns during walking or running. However, these devices are often expensive, cumbersome, or have boundary constraints that limit the participant’s motions. Recent advancements in the quality of plastic optical fiber (POF) have made it possible to manufacture a low-cost bend sensor with a novel design for use in plantar pressure monitoring. An intensity-based POF bend sensor is not only lightweight, non-invasive, and easy to construct, but it also produces a signal that requires almost no processing. In this work, we have designed, fabricated, and characterized a novel intensity POF sensor to detect the force applied by the human foot and measure the gait pattern. The sensors were put through a series of dynamic and static tests to determine their measurement range, sensitivity, and linearity, and their response was compared to that of two different commercial force sensors, including piezo resistive sensors and a clinical force platform. The results suggest that this novel POF bend sensor can be used in a wide range of applications, given its low cost and non-invasive nature. Feedback walking monitoring for ulcer prevention or sports performance could be just one of those applications.

Investigation of Impact of Walking Speed on Forces Acting on a Foot-Ground Unit

Static and dynamic methods can be used to assess the way a foot is loaded. The research question is how the pressure on the feet would vary depending on walking/running speed. This study involved 20 healthy volunteers. Dynamic measurement of foot pressure was performed using the Ortopiezometr at normal, slow, and fast paces of walking. Obtained data underwent analysis in a “Steps” program. Based on the median, the power generated by the sensors during the entire stride period is the highest during a fast walk, whereas based on the average; a walk or slow walk prevails. During a fast walk, the difference between the mean and the median of the stride period is the smallest. Regardless of the pace of gait, the energy released per unit time does not depend on the paces of the volunteers’ gaits. Conclusions: Ortopiezometr is a feasible tool for the dynamic measurement of foot pressure. For investigations on walking motions, the plantar pressure analysis system, which uses the power generated on sensors installed in the insoles of shoes, is an alternative to force or energy measurements. Regardless of the pace of the walk, the amounts of pressure applied to the foot during step are similar among healthy volunteers.

Gait Alterations in Adults after Ankle Fracture: A Systematic Review

(1) Background: Ankle fracture results in pain, swelling, stiffness and strength reduction, leading to an altered biomechanical behavior of the joint during the gait cycle. Nevertheless, a common pattern of kinematic alterations has still not been defined. To this end, we analyzed the literature on instrumental gait assessment after ankle fracture, and its correlation with evaluator-based and patient-reported outcome measures. (2) Methods: We conducted a systematic search, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, of articles published from January 2000 to June 2021 in PubMed, Embase and PEDro on instrumental gait assessment after ankle fracture. (3) Results: Several changes in gait occur after ankle fracture, including a reduction in step length, swing time, single support time, stride length, cadence, speed and an earlier foot-off time in the affected side. Additionally, trunk movement symmetry (especially vertical) is significantly reduced after ankle fracture. The instrumental assessments correlate with different clinical outcome measures. (4) Conclusions: Instrumental gait assessment can provide an objective characterization of the gait alterations after ankle fracture. Such assessment is important not only in clinical practice to assess patients’ performance but also in clinical research as a reference point to evaluate existing or new rehabilitative interventions.

Earliest parietal art: hominin hand and foot traces from the middle Pleistocene of Tibet

At Quesang on the Tibetan Plateau we report a series of hand and foot impressions that appear to have been intentionally placed on the surface of a unit of soft travertine. The travertine was deposited by water from a hot spring which is now inactive and as the travertine lithified it preserved the traces. On the basis of the sizes of the hand and foot traces, we suggest that two track-makers were involved and were likely children. We interpret this event as a deliberate artistic act that created a work of parietal art. The travertine unit on which the traces were imprinted dates to between ∼169 and 226 ka BP. This would make the site the earliest currently known example of parietal art in the world and would also provide the earliest evidence discovered to date for hominins on the High Tibetan Plateau (above 4000 m a.s.l.). This remarkable discovery adds to the body of research that identifies children as some of the earliest artists within the genus Homo.

Estimating Ground Reaction Force and Center of Pressure using Low-Cost Wearable Devices

OBJECTIVE

Ambulatory monitoring of ground reaction force (GRF) and center of pressure (CoP) could improve management of health conditions that impair mobility. Insoles instrumented with force-sensitive resistors (FSRs) are an unobtrusive, low-cost, and low-power technology for sampling GRF and CoP in real-world environments. However, FSRs have variable response characteristics that complicate estimation of GRF and CoP. This study introduces a unique data analytic pipeline that enables accurate estimation of GRF and CoP despite relatively inaccurate FSR responses. This paper also investigates whether inclusion of a complementary knee angle sensor improves estimation accuracy.

METHODS

Seventeen healthy subjects were equipped with an insole instrumented with six FSRs and a string-based knee angle sensor. Subjects walked in a straight line at self-selected slow, preferred, and fast speeds over an in-ground force platform. Twenty repetitions were performed for each speed. Supervised machine learning models estimated weight-normalized GRF and shoe size-normalized CoP, which were re-scaled to obtain GRF and CoP.

RESULTS

Anteroposterior GRF, Vertical GRF, and Anteroposterior CoP were estimated with a normalized root mean square error (NRMSE) of less than 5%. Mediolateral GRF and CoP were estimated with an NRMSE of 8.1% and 6.4%$ respectively. Knee angle-related features slightly improved GRF estimates.

CONCLUSION

Normalized models accurately estimated GRF and CoP despite deficiencies in FSR data.

SIGNIFICANCE

Ambulatory use of the proposed system could enable objective, longitudinal monitoring of severity and progression for a variety of health conditions.

Plantar Pressure Distribution Among Diabetes and Healthy Participants: A Cross-sectional Study

Background:

Plantar Pressure distribution refers to the distribution of force over the sole of the foot. Recently many studies indicate plantar pressure distribution assisted in determining and managing the impairment related to musculoskeletal disorders.

Methods:

This cross-sectional study was conducted with forty participants (20 diabetes type 2 patients +20 healthy) from Imam Abdulrahman bin Faisal University. All the measurements were taken in the morning session. To measure height and weight, participants took off their shoes and stood on the stadiometer. The body mass index determined with the help of a bioelectric impedance device to get the health level of the participants—Proclaimed diabetes type 2 patients selected for the data collection. Tekscan's Mobile Mat was used to determine the plantar pressure of healthy and diabetes participants.

Results:

The finding revealed that diabetes participants have more pressure in the mid-foot section, whereas healthy participants showed more pressure on the heel section. The metatarsal section showed similar types of pressure distribution in both participants. The result also revealed that diabetes participants have more peak pressures, time integral, and gradient than healthy participants. Significant differences between diabetes and healthy participants were existing.

Conclusions:

The findings highlight the importance of measuring plantar pressure distribution since these are known to incorporate in the main parts of the foot and thus provide a shred of constructive evidence for the total load exposer of a single leg static task.

Estimation of Various Walking Intensities Based on Wearable Plantar Pressure Sensors Using Artificial Neural Networks

Walking has been demonstrated to improve health in people with diabetes and peripheral arterial disease. However, continuous walking can produce repeated stress on the plantar foot and cause a high risk of foot ulcers. In addition, a higher walking intensity (i.e., including different speeds and durations) will increase the risk. Therefore, quantifying the walking intensity is essential for rehabilitation interventions to indicate suitable walking exercise. This study proposed a machine learning model to classify the walking speed and duration using plantar region pressure images. A wearable plantar pressure measurement system was used to measure plantar pressures during walking. An Artificial Neural Network (ANN) was adopted to develop a model for walking intensity classification using different plantar region pressure images, including the first toe (T1), the first metatarsal head (M1), the second metatarsal head (M2), and the heel (HL). The classification consisted of three walking speeds (i.e., slow at 0.8 m/s, moderate at 1.6 m/s, and fast at 2.4 m/s) and two walking durations (i.e., 10 min and 20 min). Of the 12 participants, 10 participants (720 images) were randomly selected to train the classification model, and 2 participants (144 images) were utilized to evaluate the model performance. Experimental evaluation indicated that the ANN model effectively classified different walking speeds and durations based on the plantar region pressure images. Each plantar region pressure image (i.e., T1, M1, M2, and HL) generates different accuracies of the classification model. Higher performance was achieved when classifying walking speeds (0.8 m/s, 1.6 m/s, and 2.4 m/s) and 10 min walking duration in the T1 region, evidenced by an F1-score of 0.94. The dataset T1 could be an essential variable in machine learning to classify the walking intensity at different speeds and durations.

Estimation of Knee Joint Angle Using Textile Capacitive Sensor and Artificial Neural Network Implementing with Three Shoe Types at Two Gait Speeds: A Preliminary Investigation

The lower limb joints might be affected by different shoe types and gait speeds. Monitoring joint angles might require skill and proper technique to obtain accurate data for analysis. We aimed to estimate the knee joint angle using a textile capacitive sensor and artificial neural network (ANN) implementing with three shoe types at two gait speeds. We developed a textile capacitive sensor with a simple structure design and less costly placing in insole shoes to measure the foot plantar pressure for building the deep learning models. The smartphone was used to video during walking at each condition, and Kinovea was applied to calibrate the knee joint angle. Six ANN models were created; three shoe-based ANN models, two speed-based ANN models, and one ANN model that used datasets from all experiment conditions to build a model. All ANN models at comfortable and fast gait provided a high correlation efficiency (0.75 to 0.97) with a mean relative error lower than 15% implement for three testing shoes. And compare the ANN with A convolution neural network contributes a similar result in predict the knee joint angle. A textile capacitive sensor is reliable for measuring foot plantar pressure, which could be used with the ANN algorithm to predict the knee joint angle even using high heel shoes.

Adaptive Accumulation of Plantar Pressure for Ambulatory Activity Recognition and Pedestrian Identification

In this paper, we propose a novel method for ambulatory activity recognition and pedestrian identification based on temporally adaptive weighting accumulation-based features extracted from categorical plantar pressure. The method relies on three pressure-related features, which are calculated by accumulating the pressure of the standing foot in each step over three different temporal weighting forms. In addition, we consider a feature reflecting the pressure variation. These four features characterize the standing posture in a step by differently weighting step pressure data over time. We use these features to analyze the standing foot during walking and then recognize ambulatory activities and identify pedestrians based on multilayer multiclass support vector machine classifiers. Experimental results show that the proposed method achieves 97% accuracy for the two tasks when analyzing eight consecutive steps. For faster processing, the method reaches 89.9% and 91.3% accuracy for ambulatory activity recognition and pedestrian identification considering two consecutive steps, respectively, whereas the accuracy drops to 83.3% and 82.3% when considering one step for the respective tasks. Comparative results demonstrated the high performance of the proposed method regarding accuracy and temporal sensitivity.

Towards Customized Footwear with Improved Comfort

A methodology enabling the customization of shoes for comfort improvement is proposed and assessed. For this aim, 3D printed graded density inserts were placed in one of the critical plantar pressure zones of conventional insoles, the heel. A semi-automated routine was developed to design the 3D inserts ready for printing, which comprises three main stages: (i) the definition of the number of areas with different mesh density, (ii) the generation of 2D components with continuous graded mesh density, and (iii) the generation of a 3D component having the same 2D base mesh. The adequacy of the mesh densities used in the inserts was previously assessed through compression tests, using uniform mesh density samples. Slippers with different pairs of inserts embedded in their insoles were mechanically characterized, and their comfort was qualitatively assessed by a panel of users. All users found a particular pair, or a set, of prototype slippers more comfortable than the original ones, taken as reference, but their preferences were not consensual. This emphasizes the need for shoe customization, and the usefulness of the proposed methodology to achieve such a goal.

Review of the Upright Balance Assessment Based on the Force Plate

Quantitative assessment is crucial for the evaluation of human postural balance. The force plate system is the key quantitative balance assessment method. The purpose of this study is to review the important concepts in balance assessment and analyze the experimental conditions, parameter variables, and application scope based on force plate technology. As there is a wide range of balance assessment tests and a variety of commercial force plate systems to choose from, there is room for further improvement of the test details and evaluation variables of the balance assessment. The recommendations presented in this article are the foundation and key part of the postural balance assessment; these recommendations focus on the type of force plate, the subject's foot posture, and the choice of assessment variables, which further enriches the content of posturography. In order to promote a more reasonable balance assessment method based on force plates, further methodological research and a stronger consensus are still needed.

The Design and Simulation of a 16-Sensors Plantar Pressure Insole Layout for Different Applications: From Sports to Clinics, a Pilot Study

The quantification of plantar pressure distribution is widely done in the diagnosis of lower limbs deformities, gait analysis, footwear design, and sport applications. To date, a number of pressure insole layouts have been proposed, with different configurations according to their applications. The goal of this study is to assess the validity of a 16-sensors (1.5 × 1.5 cm) pressure insole to detect plantar pressure distribution during different tasks in the clinic and sport domains. The data of 39 healthy adults, acquired with a Pedar-X® system (Novel GmbH, Munich, Germany) during walking, weight lifting, and drop landing, were used to simulate the insole. The sensors were distributed by considering the location of the peak pressure on all trials: 4 on the hindfoot, 3 on the midfoot, and 9 on the forefoot. The following variables were computed with both systems and compared by estimating the Root Mean Square Error (RMSE): Peak/Mean Pressure, Ground Reaction Force (GRF), Center of Pressure (COP), the distance between COP and the origin, the Contact Area. The lowest (0.61%) and highest (82.4%) RMSE values were detected during gait on the medial-lateral COP and the GRF, respectively. This approach could be used for testing different layouts on various applications prior to production.

Plantar Pressure Evaluation during the Season in Five Basketball Movements

Sports activity is extremely important in the health context, with a clear motivation for its practice. One of the sports that involve more athletes is basketball, where the human body undergoes rapid reactions, emphasizing the contact of the foot with the ground. The main goal of the present study is to evaluate the distribution of plantar pressure in five different basketball movements. Supported by a group of nine volunteer female athletes from a senior basketball team, a data acquisition protocol was defined to identify the changes that occur throughout the sports season. In this study, the maximum values of plantar pressure were evaluated for both feet. The five movements that were defined and studied are all movements that might be performed during the basketball practice period. To guarantee the necessary conditions of data reliability and repeatability, at least seven repetitions were performed for each movement, which occurred at two different moments of the sports season: at the beginning of the competition in November, and at season peak, four months later, in March. Overall, the results obtained did not present statistically significant changes between the two seasons in this study. However, a slight decrease was observed throughout the sporting season for all movements, except for the rebound, where there was a contrary evaluation. Additionally, athletes with a higher level of experience show higher values of plantar pressure than less experienced athletes.

Reprodutibilidade e concordância entre diferentes protocolos de baropodometria dinâmica durante a marcha: um estudo preliminar

RESUMO A identificação da pressão plantar durante a marcha é utilizada por clínicos e investigadores para verificar sobrecarga na estrutura podal. Neste particular, diferentes protocolos têm sido empregados para essa finalidade. O objetivo do estudo foi verificar a reprodutibilidade e a concordância de protocolos abreviados de marcha para identificar a pressão plantar dinâmica em jovens assintomáticos. Quinze voluntários foram submetidos aos protocolos abreviados one-step e three-step e ao protocolo padrão midgait em três momentos: inicial, dia seguinte e após sete dias. Para cada uma das oito máscaras podais, foram consideradas as medidas de pico de pressão plantar e integral pressão/tempo. A reprodutibilidade foi analisada mediante Anova one-way e coeficiente de correlação intraclasse, enquanto a concordância entre os protocolos foi verificada através de teste t pareado, correlação momento-produto de Pearson e plotagem de Bland-Altman. Os resultados apontaram que o protocolo three-step apresentou mais elevada reprodutibilidade em ambas as medidas de pressão plantar dinâmica. Quanto à concordância entre os protocolos, apesar de os abreviados demonstrarem tendência em subestimar as medidas produzidas pelo protocolo padrão midgait, na maioria das máscaras podais não foram identificadas diferenças estatísticas entre os escores médios. Ainda, por intermédio da técnica de Bland-Altman, constatou-se substancial capacidade de concordância entre as medidas identificadas pelos protocolos one-step, three-step e midgait. Concluindo, os protocolos abreviados devem ser selecionados de acordo com a medida de interesse da pressão plantar e a máscara podal a ser analisada, surgindo evidências de reprodutibilidade e concordância mais favoráveis para o uso do protocolo three-step.

Is bodyweight affecting plantar pressure distribution in children?: An observational study

The aim of this study is twofold: firstly, to investigate the plantar pressure distribution differences in children coming from 4 different weight categories and secondly to analyze the presence of sex-related plantar pressure distribution differences.Overall, 416 children, aged 7 to 12 years old were randomly selected from 6 different local schools, and voluntarily participated in the study. Two hundred twenty six of them were men, while 190 were women (mean age: 9.93 ± 1.02 years; height: 1.39 ± 0.8 m; body mass: 37.76 ± 10.34 kg; BMI: 19.24 ± 4.02 kg/m). Based on the body mass index (BMI) the sample was grouped in the following categories: underweight (UW); normal weight (NW); overweight (OW), and obese (OB). Besides, the plantar load distribution parameters (total plantar load distribution and load distribution in forefoot and rearfoot) were assessed employing freeMed Maxi; Sensor Medica device. Shapiro-Wilk test was used to test the data distribution. Between-groups comparisons were conducted using Mann-Whitney U test, or using Kruskal-Wallis test associated with pairwise comparisons.There were significant differences in load distribution between weight categories, with (OW) and (NW) being significantly different with (O), P = .03 and P = .04, respectively. No significant differences were found on load distribution on the rearfoot and forefoot between categories. The sex effect, particularly among boys, revealed a different pattern of load distribution among (O) compared with other categories. This effect was not detected among women. Different profile of load distribution on the rearfoot and forefoot between boys and girls was found, with girls bearing significantly more weight in the right rearfoot compared with boys (P = .001).It can be concluded that the weight status of the children can affect the plantar load distribution, with obese category being different from (NW) and (OW). Additionally, the sex plays a role when it comes to the load distribution in different regions of the foot. Moreover, since the young age, due to growth and development process, is accompanied with anatomical foot changes which might be affected from numerous factors, assessing plantar pressure distribution in young children results to be a quite complicated matter.

A Deep-Learning Approach for Foot-Type Classification Using Heterogeneous Pressure Data

The human foot is easily deformed owing to the innate form of the foot or an incorrect walking posture. Foot deformations not only pose a threat to foot health but also cause fatigue and pain when walking; therefore, accurate diagnoses of foot deformations are required. However, the measurement of foot deformities requires specialized personnel, and the objectivity of the diagnosis may be insufficient for professional medical personnel to assess foot deformations. Thus, it is necessary to develop an objective foot deformation classification model. In this study, a model for classifying foot types is developed using image and numerical foot pressure data. Such heterogeneous data are used to generate a fine-tuned visual geometry group-16 (VGG16) and K−nearest neighbor (k-NN) models, respectively, and a stacking ensemble model is finally generated to improve accuracy and robustness by combining the two models. Through k-fold cross-validation, the accuracy and robustness of the proposed method have been verified by the mean and standard deviation of the f1 scores (0.9255 and 0.0042), which has superior performance compared to single models generated using only numerical or image data. Thus, the proposed model provides the objectivity of diagnosis for foot deformation, and can be used for analysis and design of foot healthcare products.

Plantar pressure sensors indicate women to have a significantly higher peak pressure on the hallux, toes, forefoot, and medial of the foot compared to men

BACKGROUND

Sex-related differences of plantar pressure distribution during activities should be thoroughly inspected as it can help establish treatment and prevention strategies for foot and ankle problems. In-shoe measurement systems are preferable without space and activity restrictions; however, previously reported systems are still heavy and bulky and induce unnatural movement. Therefore, a slim and light plantar pressure sensor was newly developed to detect the effect of sex difference on plantar pressure during standing and walking.

METHODS

One-hundred healthy adult volunteers (50 women and 50 men) were recruited. Ten plantar pressure sensors were implanted in a 1-mm thick insole, with a total weight of 29 g. Plantar pressure was recorded with 200 Hz during 3 s of standing and while walking 10 steps. The maximum loads during standing and walking were analyzed in each sensor, and the results were compared between different areas of the foot in the antero-posterior direction and the medio-lateral direction and between different time points. The movement of the center of pressure (COP) during walking was also evaluated. Analyses were adjusted for body mass index and gait speed.

RESULTS

The movement of COP was constant for both sexes. In all cases, the maximum load was observed on the medial of the foot. Women had a significantly higher peak pressure on the hallux, toes, forefoot, and medial aspect of the foot compared to men while standing and walking (p < .05).

CONCLUSIONS

A newly introduced in-shoe plantar pressure sensor demonstrated a typical loading transition pattern of the foot. Furthermore, higher plantar pressure in the forefoot was detected in healthy women as compared to men during standing and walking activities.

Smartphone Use and Postural Balance in Healthy Young Adults

Maintaining an upright posture while talking or texting on the phone is a frequent dual-task demand. Using a within-subjects design, the aim of the present study was to assess the impact of a smartphone conversation or message texting on standing plantar pressure and postural balance performance in healthy young adults. Thirty-five subjects (mean age 21.37 ± 1.11 years) were included in this study. Simultaneous foot plantar pressure and stabilometric analysis were performed using the PoData system, under three conditions: no phone (control), talking on a smartphone (talk) and texting and sending a text message via a smartphone (text). Stabilometric parameters (center of pressure (CoP) path length, 90% confidence area and maximum CoP speed) were significantly affected by the use of different smartphone functions (p < 0.0001). The CoP path length and maximum CoP speed were significantly higher under the talk and text conditions when compared to the control. CoP path length, 90% confidence area and maximum CoP speed were significantly increased in talk compared to text and control. Talking on the phone also influenced the weight distribution on the left foot first metatarsal head and heel as compared with message texting. Postural stability in healthy young adults was significantly affected by talking and texting on a smartphone. Talking on the phone proved to be more challenging.

Static plantar pressure and functional capacity in children with femoral shaft fractures treated by titanium elastic nailing

Background

Femoral shaft fractures represent common fractures of the lower limb in the paediatric population. The objectives of our study were to analyse the static plantar pressure and functional capacity in children with surgically treated unilateral femoral shaft fractures, 1 month after the metallic implant removal.

Methods

Our study included 24 children with unilateral femoral shaft fracture (fracture site contralateral to the dominant leg) treated by titanium elastic nailing (TEN) implants, with the removal of the implant 6 months after initial surgery. The patients were divided into two groups: Group 1 (12 patients without inpatient rehabilitation) and Group 2 (12 patients who attended inpatient rehabilitation). The patients and 12 gender and age-matched healthy controls performed plantar pressure analysis and functional capacity testing (6-min walk test: 6MWT). For patients in Group 1 and 2 the assessments were performed 1 month after the TEN implant removal. Paired t-tests were used to compare the intragroup data. A one-way ANOVA test for independent measures was performed to assess the differences for plantar pressure, and 6MWT among study groups and controls.

Results

All study patients had left femoral shaft fractures (affected limb). The patients and controls were all right leg dominant. In both Group 1 and Group 2 total foot loading was significantly higher on the non-affected limb compared with the affected limb. When compared to the non-affected limb, the loadings on the affected limb were significantly increased on the first and fifth metatarsal in Group 1, and on the fifth metatarsal in Group 2, with a significantly smaller heel loading. When compared with the controls we found significant differences for all pressure parameters, except for the right foot load for the rehabilitation group. Although the functional capacity values were higher in the rehabilitation group the two patients groups had significantly lower 6MWT values.

Conclusions

When compared to healthy controls children with surgically treated unilateral femoral shaft fractures, although assessed after 7 months, had a different weight distribution on the feet and a decreased functional capacity. A rehabilitation programme included in the management of these patients is important for regaining their functional level.

Distribution of the Highest Plantar Pressure Regions in Patients with Diabetes and Its Association with Peripheral Neuropathy, Gender, Age, and BMI: One Centre Study

The abnormal plantar pressure distribution and value play a key role in the formation of plantar calluses and diabetic foot ulcer. The prevalence of the highest pressure different distribution and its association with various factors among patients with diabetes is not well known. The study purpose was to evaluate the prevalence of different regions for the highest pressure on the sole and its association with selected factors among patients with diabetes. Medical records of nonulcer patients were retrospectively analysed. The relationship between pressure patterns on the sole obtained during a pedobarographic test as a semiquantitative assessment with colourful print analysis and neuropathy, gender, age, and BMI was searched. The most common location of the highest pressure was the central part of the forefoot. No association was found between the different highest pressure regions and age, sensory neuropathy, calluses, and foot deformities. The highest pressure on the lateral part of the foot and midfoot was observed more often in females and in patients with a BMI ≥ 35. The prevalence of the highest pressure on the forefoot was more common in patients with a BMI < 35. Conclusions. The most frequent regions of the highest pressure on the sole in patients with diabetes were the central part of the forefoot (2-3 metatarsal heads) with no simple relationship to the assessed variables other than BMI < 35. Female gender and higher BMI seem to be responsible for shifting the place of the highest pressure to other places of the foot.