Search Results (46)

Diabetic foot ulcers (DFUs) represent a critical global health issue, necessitating the development of advanced smart, flexible, and wearable sensors for continuous monitoring that are reimbursable within foot orthotics. This study presents the design and characterization of a pressure sensor implemented into a shoe insole to monitor diabetic wound pressures, emphasizing the need for a high sensitivity, durability under cyclic mechanical loading, and a rapid response time. This investigation focuses on the electrical and mechanical properties of carbon nanotube (CNT) composites utilizing Ecoflex and polydimethylsiloxane (PDMS). Morphological characterization was conducted using Transmission Electron Microscopy (TEM), Laser Confocal Microscopy, and Scanning Electron Microscopy (SEM). The electrical and mechanical properties of the CNT/Ecoflex- and the CNT/PDMS-based sensor composites were then investigated. CNT/Ecoflex was then further evaluated due to its lower variability performance between cycles at the same pressure, as well as its consistently higher capacitance values across all trials in comparison to CNT/PDMS. The CNT/Ecoflex composite sensor showed a high sensitivity (2.38 to 3.40 kPa⁻¹) over a pressure sensing range of 0 to 68.95 kPa. The sensor’s stability was further assessed under applied pressures simulating human weight. A custom insole prototype, incorporating 12 CNT/Ecoflex elastomeric matrix-based sensors (as an example) distributed across the metatarsal heads, midfoot, and heel regions, was developed and characterized. Capacitance measurements, ranging from 0.25 pF to 60 pF, were obtained across N = 3 feasibility trials, demonstrating the sensor’s response to varying pressure conditions linked to different body weights. These results highlight the potential of this flexible insole prototype for precise and real-time plantar surface monitoring, offering an approachable avenue for a challenging diabetic orthotics application. Full article

The first ray plays a fundamental role in foot biomechanics, particularly in stabilizing the medial longitudinal arch and enabling efficient weight transfer during the mid-stance and propulsion phases of gait. When dorsiflexed—a condition known as metatarsus primus elevatus—especially in its flexible form, this structure disrupts load distribution, impairs propulsion, and contributes to various clinical symptoms. Despite its clinical importance, the biomechanical impact of orthotic elements placed beneath the first ray remains underexplored. This study aimed to quantify the variations in medio-lateral (Fx), antero-posterior (Fy), and vertical (Fz) force vectors generated during gait in response to different orthotic elements positioned under the first ray. A quasi-experimental, post-test design was conducted involving 22 participants (10 men and 12 women) diagnosed with flexible metatarsus primus elevatus. Each participant was evaluated using custom-made insoles incorporating various orthotic elements, while gait data were collected using a dynamometric platform during the mid-stance and propulsion phases. Significant gait-phase-dependent force alterations were observed. A cut-out (E) reduced medio-lateral forces during propulsion (p < 0.05), while a kinetic wedge (F) was correlated with late-stance stability (r = −0.526). The foot posture index (FPI)/body mass index (BMI) mediated the vertical forces. The effect sizes reached 0.45–0.42 for antero-posterior force modulation. Phase-targeted orthoses (a cut-out for propulsion, a kinetic wedge for late stance) and patient factors (FPI/BMI) appear to promote biomechanical efficacy in metatarsus primus elevatus, enabling personalized therapeutic strategies. Full article

Background and Objectives: Weight-bearing activities exacerbate pain and fatigue in functional flat foot, with uphill walking presenting additional challenges due to increased external loads. The current study investigates whether 3D-printed customized arch-support insoles can enhance gait variables and ankle alignment during uphill walking. Materials and Methods: Twenty healthy young adults, divided into two groups (normal foot condition (control, n = 10), functional flat foot (FF, n = 10)), walked on a treadmill at a 10% incline under two conditions: wearing shoes alone (shoe) or wearing shoes with 3D-printed customized arch-support insoles (SI). Gait pattern, center of force (COF), and ankle joint angles were analyzed by OptoGait, Tekscan, and Kinovea, respectively. Results: The foot flat phase of the gait pattern was prolonged in individuals with FF compared to the control under both shoe and SI conditions, whereas the propulsive phase was shortened with the SI. Medial deviation of the COF during the propulsive phase, observed in individuals with FF under the shoe condition, was corrected to a more lateral alignment with the SI, resembling the COF alignment of the control. Additionally, individuals with FF under the shoe condition exhibited increased ankle pronation compared to the control, whereas the SI moderated pronation, achieving alignment closer to that of the control. Conclusions: These findings indicate that the 3D-printed customized arch-support insoles can improve gait mechanics and ankle alignment in individuals with FF, particularly under challenging conditions such as uphill walking. Full article

This study investigates the benefits of innovative full-contact insoles, crafted using polyester fabric sheets of thermoplastic extruded materials, for individuals with hallux valgus-induced plantar pain. Thirty-five individuals with hallux valgus-induced foot pain were randomly allocated to either the experimental group, wearing innovative full-contact insoles 6 h daily, or the control group, using regular foot insoles, over a period of 12 weeks. Data collection occurred at baseline, and at 1 week, 2 months, and 3 months after the initial fitting. Results indicated that the innovative full-contact insoles significantly reduced anteroposterior displacement by an average of 0.9 cm (p = 0.025) and displacement area by 0.79 cm² (p = 0.012). Gait improvements included an increase in the swing phase (36.46%, p = 0.008) and a reduction in stance phase duration (63.54%, p = 0.019). Pressure peaks at critical foot regions like the second metatarsal and medial heel were reduced by up to 39.45 kPa (p = 0.016) and 104.07 kPa (p = 0.031), while contact areas in the midfoot increased by 6.17 cm² (p = 0.039). Foot pain decreased by an average score of 1.28 points on a 10-point scale across various measures (p = 0.041). These findings suggest that the innovative full-contact insoles effectively enhance pressure distribution and gait dynamics in patients with hallux valgus, providing a viable option for managing foot discomfort. Full article

Background: Flatfoot deformity is a common condition in children and teenagers that may increase the risk of knee, hip, and back pain. Most of the insoles suggested to treat flatfoot symptoms are not designed to adapt to foot temperature during walking, and they are either too soft to provide support or hard enough to be uncomfortable. Purpose: This study aims to develop an advanced solution to diagnose and treat flexible flatfoot (FFT) using infrared thermography measurements and a hybrid insole reinforced by nitinol (NiTiCu) smart-memory-alloy wires (SMAWs), this super-elastic alloy can return back to its pre-deformed shape when heated, which helps to reduce the local high-temperature points caused by the uneven pressure of FFT. This approach achieves a more uniform thermal distribution across the foot, which makes the hybrid insole more comfortable. Methods: The study involved 16 subjects, divided into two groups of eight flat-footed and eight normal. The procedure includes two parts, namely, designing a prototype insole with SMAW properties based on thermography measurement by using SolidWorks, and evaluating this design using Ansys. Second, a hybrid insole reinforced with SMAWs is customized for flatfoot subjects. The thermography measurement differences between the medial and lateral sides of the metatarsophalangeal line are compared for the normal and flatfoot groups before and after wearing the suggested design. Results: The results show that our approach safely diagnosed FFT and significantly improved the thermal distribution in FFT subjects by more than 80% after wearing the suggested design. A paired t-test reported significant (p-value > 0.001) thermal decreases in the high-temperature points after using the SMAW insole, which was closely approximated to the normal subjects. Conclusions: the SMAW-reinforced insole is comfortable and suitable for treating FFT deformity, and infrared thermography is an effective tool to evaluate FFT deformity. Full article

Background: Lacing techniques are often viewed as a functional necessity, but recent research has highlighted their role as a customization tool for foot health and comfort. This review synthesizes findings from studies examining the biomechanical effects of different lacing patterns on pressure distribution, tendon loading, and foot mechanics. Methods: We analyzed studies that investigated various lacing techniques, including tightness and patterns. Objective measurements, such as pressure insoles and cadaveric models, were used to quantify the effects. Diverse study populations, including individuals with foot health concerns and athletes, were considered. This study was conducted as a scoping review following the JBI methodology, adhering to the PRISMA-ScR guidelines. Results: The studies collectively reveal that lacing patterns significantly influence dorsal pressure distribution during activities like running. Customized lacing can optimize foot biomechanics, reducing the risk of injuries related to abnormal pressure distribution. A total of 27 records were identified from the initial search. After removing duplicates and screening, four articles were included in the final review. Additionally, certain lacing configurations were found to reduce peak Achilles tendon tension, a crucial finding for injury-prone individuals. Conclusions: Proper lacing techniques are not just a functional aspect but a means to enhance foot health and prevent injuries. Healthcare professionals can provide personalized lacing recommendations to patients, with implications for those with specific foot conditions, athletes, and individuals at risk of injuries. The importance of patient education on the significance of lacing techniques cannot be overstated, emphasizing the need for informed choices when lacing shoes. These findings underscore the multifaceted role of lacing techniques in promoting foot health and well-being. Full article

The aim of this study was to evaluate the validity of an orthotic deformation test on insole arches and the impact of researcher expertise on the test’s reproducibility. Three researchers with different levels of experience evaluated orthotic deformation by applying a vertical force with their thumb on the dorsal surface of 48 polypropylene orthoses. An electromechanical test machine was used to evaluate the stiffness of the orthoses, and the results were compared with those of the orthotic deformation tests. Fleiss’ kappa and weighted kappa and Mann–Whitney U tests were used to evaluate the interobserver reliability and the validity, respectively. There was no consensus among the three researchers (Kappa = 0.080; p-value = 0.334), although the two researchers with higher levels of experience exhibited moderate consensus (Kappa = 0.52; p-value < 0.001). Orthoses characterised by a positive test suffered from more pronounced deformation when a constant vertical force was applied by the electromechanical test machine (5.62 [4.64–7.38] vs. 4.56 [3.59–5.28] mm; p-value = 0.003). The orthotic deformation test is valid for interpreting the degree of deformation of polypropylene custom orthoses when it is compared with an axial force from a compression-device test. However, considering the high dispersion of the results, it suggests that clinical experience is required to properly interpret the tests. Full article

This paper proposes a scheme for predicting ground reaction force (GRF) and center of pressure (CoP) using low-cost FSR sensors. GRF and CoP data are commonly collected from smart insoles to analyze the wearer’s gait and diagnose balance issues. This approach can be utilized to improve a user’s rehabilitation process and enable customized treatment plans for patients with specific diseases, making it a useful technology in many fields. However, the conventional measuring equipment for directly monitoring GRF and CoP values, such as F-Scan, is expensive, posing a challenge to commercialization in the industry. To solve this problem, this paper proposes a technology to predict relevant indicators using only low-cost Force Sensing Resistor (FSR) sensors instead of expensive equipment. In this study, data were collected from subjects simultaneously wearing a low-cost FSR Sensor and an F-Scan device, and the relationship between the collected data sets was analyzed using supervised learning techniques. Using the proposed technique, an artificial neural network was constructed that can derive a predicted value close to the actual F-Scan values using only the data from the FSR Sensor. In this process, GRF and CoP were calculated using six virtual forces instead of the pressure value of the entire sole. It was verified through various simulations that it is possible to achieve an improved prediction accuracy of more than 30% when using the proposed technique compared to conventional prediction techniques. Full article

The study of the phenomena occurring in the plantar region is remarkably intriguing, especially when performing a normal gait cycle where the foot is under loading conditions. The effects presented in the foot while walking provide relevant indicators regarding clinical means for enhancing regular performance or rehabilitation therapies. Nevertheless, more than traditional methods are needed to biomechanically evaluate foot structural conditions, leading to an incomplete database for determining the patient’s needs so that advanced methodologies provide detailed medical assessment. Therefore, it is necessary to employ technological engineering tools to optimize biomechanical plantar pressure evaluations to reach suitable personalized treatments. This research initially evaluated numerically the pressure points in the foot sole region in each one of the five stance phases in a normal gait cycle. Medical imaging techniques were utilized to construct an anatomically accurate biomodel of the soft tissues of the right foot. The Finite Element Method was employed to predict peak plantar pressure in barefoot conditions for all stance phases; results from this case study presented a close alignment with gait experimental testing implemented to analyze the feasibility and validation of all mechanical considerations for the numerical analyses. Hence, having a solid foundation in the biomechanical behavior from the first case study close estimates, a 3D-printable patient-specific insole was designed and numerically analyzed to observe the mechanical response in the plantar critical zones utilizing a personalized orthotic device. Results from the second case study notably demonstrated a crucial decrement in excessive pressure values. Employing morphological customization orthopedics modeling combined with 3D-printable materials is revolutionizing assistive device design and fabrication techniques. The fundamental contribution of this research relies on deepening the knowledge of foot biomechanics from an interdisciplinary approach by numerically analyzing pressure distribution in critical regions for all five stances phases; thus, based on the methods employed, the results obtained contribute to the advances of patient-specific foot orthopedics. Full article

Introduction: Diabetic foot ulcers (DFU) are a devastating complication of diabetes. There are numerous challenges with preventing diabetic foot complications and barriers to achieving the care processes suggested in established foot care guidelines. Multi-faceted digital health solutions, which combine multimodal sensing, patient-facing biofeedback, and remote patient monitoring (RPM), show promise in improving our ability to understand, prevent, and manage DFUs. Methods: Patients with a history of diabetic plantar foot ulcers were enrolled in a prospective cohort study and equipped with custom sensory insoles to track plantar pressure, plantar temperature, step count, and adherence data. Sensory insole data enabled patient-facing biofeedback to cue active plantar offloading in response to sustained high plantar pressures, and RPM assessments in response to data trends of concern in plantar pressure, plantar temperature, or sensory insole adherence. Three non-consecutive case participants that ultimately presented with pre-ulcerative lesions (a callus and/or erythematous area on the plantar surface of the foot) during the study were selected for this case series. Results: Across three illustrative patients, continuous plantar pressure monitoring demonstrated promise for empowering both the patient and provider with information for data-driven management of pressure offloading treatments. Conclusion: Multi-faceted digital health solutions can naturally enable and reinforce the integrative foot care guidelines. Multi-modal sensing across multiple physiologic domains supports the monitoring of foot health at various stages along the DFU pathogenesis pathway. Furthermore, digital health solutions equipped with remote patient monitoring unlock new opportunities for personalizing treatments, providing periodic self-care reinforcement, and encouraging patient engagement—key tools for improving patient adherence to their diabetic foot care plan. Full article

The number of people with diabetes is rising day-by-day, which also raises the incidence of diabetic ulcers, sensation loss in the foot’s plantar area, and in extreme instances, amputations. Using customized shoes, unloading orthoses, insoles, and other strategies may help control these issues to some degree. In this work, a novel modular diabetic insole was designed and fabricated to effectively offload the abnormal or peak plantar pressures in diabetic patients. The pressure values in the plantar region were quantified using an in-house-developed plantar pressure-measuring insole consisting of force sensitive resistor (FSR) sensors. The effectiveness of the modular diabetic insole was tested qualitatively and quantitatively. The qualitative performance of the insole was reported using Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) in terms of subjective parameters like comfort, ease of use, effectiveness, etc. and calculated as 4.7 ± 0.18. Thereafter, the wearable pressure-measuring insole was used to investigate the feasibility of modular insole for the plantar pressure offloading during standing and walking conditions. It was observed that the maximum average zonal pressure (AZP) was reduced by up to 99% from 121.30 ± 3.72 kPa to 0.22 ± 0.18 kPa for the standing condition whereas it was reduced to 6.76 ± 2.03 kPa from 197.71 ± 3.21 kPa with a percentage value of 96% for the walking condition. In conclusion, the findings of this work validate the effectiveness of the modular diabetic insole as an intervention tool for diabetic foot ulcer prevention. Full article

Plantar pressure distribution is a thoroughly recognized parameter for evaluating foot structure and biomechanical behavior, as it is utilized to determine musculoskeletal conditions and diagnose foot abnormalities. Experimental testing is currently being utilized to investigate static foot conditions using invasive and noninvasive techniques. These methods are usually expensive and laborious, and they lack valuable data since they only evaluate compressive forces, missing the complex stress combinations the foot undergoes while standing. The present investigation applied medical and engineering methods to predict pressure points in a healthy foot soft tissue during normal standing conditions. Thus, a well-defined three-dimensional foot biomodel was constructed to be numerically analyzed through medical imaging. Two study cases were developed through a structural finite element analysis. The first study was developed to evaluate barefoot behavior deformation and stresses occurring in the plantar region. The results from this analysis were validated through baropodometric testing. Subsequently, a customized 3D model total-contact foot orthosis was designed to redistribute peak pressures appropriately, relieving the plantar region from excessive stress. The results in the first study case successfully demonstrated the prediction of the foot sole regions more prone to suffer a pressure concentration since the values are in good agreement with experimental testing. Employing a customized insole proved to be highly advantageous in fulfilling its primary function, reducing peak pressure points substantially. The main aim of this paper was to provide more precise insights into the biomechanical behavior of foot pressure points through engineering methods oriented towards innovative assessment for absolute customization for orthotic devices. Full article

Subjects with Parkinson’s Disease (PD) display different motor and non-motor symptoms. Different therapies have been shown to be effective, such as plantar foot stimulation, which has proved to be effective for motor symptoms. Different stimulation methods were proposed and tested through specific devices, or insoles. Our aim was to assess the effect of a newly designed custom-made insole called PRO-STEP compared with a flat sham insole on subjects with PD. Subjects were randomized 1:1 into two arms and were asked to wear PRO-STEP or sham insoles for at least 6 h per day for 10 weeks. Participants were evaluated at four timepoints. Forty-two subjects were randomly assigned to the PRO-STEP (EG) or sham group (SG). The comparison of the EG and SG without and with insoles (T0–T1) did not show significant differences in the TUG time and in the 10MWT gait parameters. At T1, T2, and T3 TUG time, BBS, SF12-MC, and SF12-PC did not show significant differences. The satisfaction level with the PRO-STEP or sham insoles was high in both groups. PD patients were satisfied with PRO-STEP insoles; however, plantar foot stimulation is not effective from a functional perspective. Future studies should consider possible modifications to the proposed stimulation to improve its effectiveness in patients with PD. Full article

Nowadays there are various prosthetic arm designs in the literature, the market, and CAD design websites, with different shapes, sizes, and degrees of freedom. Only limited options are available for controlling such prostheses. Prosthetic arm users reported muscle fatigue and unreliability when using the market-dominated myoelectric sensors. This work presents the “Infinity Foot Controller” as a new approach to control a five-finger below-the-elbow prosthetic arm with wrist rotation and bending capabilities. This foot control system receives user input from a custom insole and a sensor-controller unit placed alongside the user’s shoe to perform various hand grips, gestures, and/or rotations. To demonstrate the new foot controller, a design of a 3D-printed below-the-elbow prosthetic arm, called the “Infinity Arm”, is presented. This arm is suitable for gripping relatively lightweight objects and making hand gestures. It includes a wrist actuation system that permits 120° wrist rotation and 70° wrist extension and flexion. It also includes a haptic feedback system that utilizes fingertip force sensors to relay a vibratory response in an armband placed on the user’s arm, giving the user a sense of touch. A proof-of-concept model was built to demonstrate the system and a testing procedure was proposed. Full article

The management of tibial pilon fractures is challenging and often leads to complications and limitations in ankle function. The study aims to investigate myotonometric parameters and muscle strength of ankle muscles, as well as gait pattern and balance among patients following surgical treatment of pilon fractures. The randomized controlled study will analyze the differences between the patients who will follow a 3-month physical exercise program and will wear customized foot orthoses (i.e., customized orthotic arch support insoles) versus patients who will attend only the physical exercise program. For each group, at least 21 patients will be required. The assessment involves four different testing procedures: myotonometry (anterior tibialis, medial and lateral gastrocnemius, and longus peroneus assessed using MyotonPRO), muscle strength testing (ankle dorsiflexors, plantar flexors, and peroneal muscles assessed using MicroFET2 dynamometer), analysis of gait parameters (using Scheinworks treadmill), and double-leg and single-leg balance tests (using K-Force plate). After 3 months, the assessments will record which of the two treatments (physical exercise program with or without wearing customized foot orthoses) has better outcomes in regaining ankle muscle properties and tone, as well as the restoration of gait and balance. Full article