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Objetivo do estudo é analisar o índice de arco plantar e distribuição de pressões plantares em sujeitos submetidos a procedimento cirúrgico, a fim de compreender o comportamento dos parâmetros plantares nestas duas patologias, como forma de ser utilizada como uma avaliação complementar no tratamento cirúrgico de reconstrução do ligamento cruzado anterior e artroplastia total de joelho. Participaram destes estudos 29 adultos e idosos de ambos os sexos que seriam submetidos a cirurgia de reconstrução de ligamento cruzado anterior (LCA) e artroplastia total de joelho (ATJ), foi utilizado uma plataforma de pressão plantar para realizar a análise de distribuição de pressões plantares (Superfície de contato do pé, pressão máxima, pressão média, distribuição de pressão plantar do retropé, distribuição de pressão plantar do antepé) e índice de arco plantar (IAP). Para a superfície de contato do pé (direito e esquerdo) tanto o Grupo_LCA e Grupo_ATJ apresentaram um comportamento parecido entre o pé direito e o pé esquerdo. Já para a Pressão Máxima o Grupo_ATJ apresentam valores maiores tanto no pé direito quanto no pé esquerdo quando comparados com o Grupo_LCA (p = 0.03). A distribuição plantar na área do retropé no pé esquerdo e no pé direito no Grupo_ATJ foi maior que no Grupo_LCA (p=0.03). E na área do antepé o Grupo_ATJ apresentou menores distribuições de pressões plantares no pé direito e pé esquerdo quando comparado com o Grupo_LCA (p = 0.03). Podemos concluir que a região plantar apresenta diferentes adaptações conforme os dois tipos de lesões de joelho, sendo assim sendo assim solicita as diferentes áreas do pé para executar o desempenho de ficar em pé parado em sua base de apoio.

Introduction: This study aimed to compare plantar pressure distribution and vertical ground reaction force between middle-aged adults with Leg Length Discrepancy (LLD) and healthy subjects. Materials and Methods: This quasi-experimental study was conducted on 21 middle-aged adults with leg length discrepancy (1.5 to 3 cm), and 10 healthy subjects participated. The plantar pressure distribution of subjects was measured using five steps with an emed platform. The data were analyzed with paired t-test, 1-way ANOVA, and symmetry index (P≤0.05). Results: While the symmetry index did not show much asymmetry in healthy subjects, in LLD subjects, it showed lower contact time in the heel region of short limb, lower pressure, and force of the middle region of short limb, the higher pressure of forefoot region of short limb and higher pressure and force of long limb. Conclusion: It seems that the primary contact time and weight acceptance of short limb reduced that results in higher pressure of forefoot region of the foot before push-off phase. Therefore, to dispel this problem, the LLD subjects could use orthotics to make reasonable height to the heel region and thus increase the contact time.

Background and Objectives: Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unknown pathogenesis. Gait analysis can objectively assess the functional behavior of the foot, thus revealing essential aspects and influencing factors of gait abnormalities. The aim of this study was to evaluate the differences in spatiotemporal parameters, static and dynamic plantar pressure parameters, and symmetry indices between patients with ONFH and healthy subjects. Materials and Methods: The study population consisted of 31 ONFH patients and 31 healthy volunteers. Gait parameters were obtained from the plantar pressure analysis system for both the ONFH and healthy groups. The symmetry index was calculated according to a formula, including spatiotemporal parameters, static and dynamic plantar pressure distribution, percentage of regional impulse, and percentage of the restricted contact area. Results: Compared with healthy controls, patients with ONFH had slower walking speed, shorter step length and stride length, and increased stride time, stance time, and percentage of stance. patients with ONFH had lower plantar static pressure on the affected side and higher contralateral plantar static pressure during stance than controls. During walking, the peak pressures in all regions on the affected side and the peak pressure in the toe 1 and metatarsal 3 regions on the healthy side were lower in ONFH patients than in controls. The percentage of contact area and regional impulse in the heel of both limbs were higher in ONFH patients than in the control group. The symmetry indexes of stride time, stance time, step length, maximum force, impulse and contacted area were significantly increased in ONFH patients compared to controls, with decreased symmetry. Conclusions: Osteonecrosis of the femoral head leads to characteristic changes in plantar pressure distribution. These changes may be interpreted as an attempt by patients with ONFH to reduce the load on the affected limb. Plantar pressure analysis may assist in the diagnosis of ONFH and can provide an objective quantitative indicator for the assessment of subsequent treatment outcomes.

Purpose. the aim of the study was (a) to investigate the differences in plantar pressure distribution between athletes (A) and sedentary (S) women; (b) to examine the differences, if any, in plantar pressure between sports within the A group. Methods. the study involved 173 females; 98 were S (age: 24.23 ± 6.11 years; height: 161.11 ± 6.44 cm; weight: 56.70 ± 8.19 kg; bMI: 21.81 ± 2.52 kg/m 2 ; body surface area [bSA]: 1.59 ± 0.13; shoe size: 37.83 ± 1.53), 75 were A (age: 22.47 ± 4.89 years; height: 159.98 ± 5.95 cm; weight: 55.49 ± 7.61 kg; bMI: 21.62 ± 2.18 kg/m 2 ; bSA: 1.57 ± 0.12; shoe size: 38.05 ± 1.55). For plantar support analysis, the FreeMed posturography system was used, including the FreeMed baropodometric platform and FreeStep v. 1.0.3 software. Results. No significant differences were found between groups regarding anthropometric data, in the total surface, fore-foot, rear-foot, total left or total right foot surface. Significant differences between S and A were observed in fore-foot (S: 50.39 ± 3.60%; A: 52.36 ± 3.76%) and rear-foot load distribution (p= 0.0006; p= 0.0006). Also the maximal peak pressure (S: 518.06 ± 111. 50 g /c m 2 ; A: 445.38 ± 88.47 g/cm 2 ) and the mean pressure showed significant differences between groups. there were significant differences between sports in total surface and fore-/rear-foot and total left/right surfaces ratios. Conclusions. Women practising sport differ from sedentary ones in the fore-/rear-foot pressure ratio. In addition, we detected plantar surface and fore-/rear-foot pressure ratio differences within the athletes group.

The evolution of low power electronics and the availability of new smart materials are opening new frontiers to develop wearable systems for medical applications, lifestyle monitoring, and performance detection. This paper presents the development and realization of a novel smart insole for monitoring the plantar pressure distribution and gait parameters, indeed, it includes a piezoresistive sensing matrix based on a Velostat layer for transducing applied pressure into an electric signal. At first, an accurate and complete characterization of Velostat-based pressure sensors is reported as a function of sizes, support material, and pressure trend. The realization and testing of a low-cost and reliable piezoresistive sensing matrix based on a sandwich structure are discussed. This last is interfaced with a low power conditioning and processing section based on an Arduino Lilypad board and an analog multiplexer for acquiring the pressure data. The insole includes a 3-axis capacitive accelerometer for detecting the gait parameters (swing time and stance phase time) featuring the walking. A Bluetooth Low Energy (BLE) 5.0 module is included for transmitting in real-time the acquired data toward a PC, tablet or smartphone, for displaying and processing them using a custom Processing® application. Moreover, the smart insole is equipped with a piezoelectric harvesting section for scavenging energy from walking. The onfield tests indicate that for a walking speed higher than 1 ms−1, the device’s power requirements (i.e., ) was fulfilled. However, more than 9 days of autonomy are guaranteed by the integrated 380-mAh Lipo battery in the total absence of energy contributions from the harvesting section.

Introduction. Many studies have compared different backpack designs and their influence on the carrier; however, no data referring to school students aged 7-8 years are currently available. Therefore, the aim of the research was to assess the influence of backpack design on centre of pressure (COP) displacement and plantar force distribution in children during an upright stance. Material and methods. Nineteen school students (9 males and 10 females) volunteered for the study. Two Polish backpacks intended for school use were evaluated: backpack A, which had two main compartments, and backpack B, which had one main compartment. The backpack load was composed of books, binders, and regular school equipment. During the measurements, the subjects were asked to look ahead with the head straight and arms at the sides in a comfortable position and to stand barefoot on the F-Scan® sensors (Tekscan, F-Scan®) attached to the force platform (Kistler), carrying a load corresponding to 10% of their body mass. Results. The study found insignificant differences between the two backpack designs. Moreover, COP parameters increased significantly during an upright stance while carrying backpack B in comparison to the empty backpack condition. Additionally, we observed significantly higher values of plantar force distribution in the heel region for the condition without load and insignificantly higher ones for carrying backpack A. Conclusions. The results of the current study suggest that the differences between the two backpack designs are too marginal to be detected through COP displacement. Disturbances in plantar force distribution suggest a lack of posture control and a lower stability of the standing position with a backpack, but these disturbances were significant only when the backpack with one main compartment was used.

Kinetic models of human motion rely on boundary conditions which are defined by the interaction of the body with its environment. In the simplest case, this interaction is limited to the foot contact with the ground and is given by the so called ground reaction force (GRF). A major challenge in the reconstruction of GRF from kinematic data is the double support phase, referring to the state with multiple ground contacts. In this case, the GRF prediction is not well defined. In this work we present an approach to reconstruct and distribute vertical GRF (vGRF) to each foot separately, using only kinematic data. We propose the biomechanically inspired force shadow method (FSM) to obtain a unique solution for any contact phase, including double support, of an arbitrary motion. We create a kinematic based function, model an anatomical foot shape and mimic the effect of hip muscle activations. We compare our estimations with the measurements of a Zebris pressure plate and obtain correlations of 0.39&le, r&le, 0.94 for double support motions and 0.83&le, 0.87 for a walking motion. The presented data is based on inertial human motion capture, showing the applicability for scenarios outside the laboratory. The proposed approach has low computational complexity and allows for online vGRF estimation.

Objective: The aim of this study was to determine the alterations of walking energy expenditure and plantar pressure distribution in young adults with patellofemoral pain syndrome (PFPS). Methods: Thirty five individuals (mean age: 21.31 ± 1.76) with PFPS constituted the patient group and forty healthy participants (mean age: 21.40 ± 2.11) the control group. Preferred walking speeds (PWS) were determined on the over ground. Individuals walked on a treadmill for 7 min at their PWS and 30% above PWS and oxygen consumption was recorded via a metabolic analyzer. Net oxygen consumption was calculated for each walking trial. Borg scale was applied to assess perceived exertion during walking trial. Plantar pressure distributions were measured by a pedobarography device. Plantar area was subdivided into six zones to evaluate the dynamic plantar pressure data. Results: The mean PWS of PFPS and control groups were 4.69 ± 0.51 and 4.52 ± 0.60 km/h, respectively (p > .09). No significant difference was observed in energy expenditure during walking at PWS between 2 groups while oxygen consumption during 30% above PWS was higher in patient group (18.72 ± 3.75 and 16.64 ± 3.27) (p = .007). Net oxygen consumption was also found to be higher in PFPS group (15.12 ± 3.62 and 13.04 ± 3.24) (p = .005). The mean Borg scores were significantly higher in PFPS group at each walking trials (p .05). Conclusion: Although, rate of perceived exertion and energy expenditure during walking at 30% above PWS are affected negatively in young adults with PFPS, we may speculate that energy consumption and plantar pressure distribution can be compensated by a physiologic adaptation mechanism during walking at PWS. Level of evidence: Level III, Therapeutic Study. Keywords: Energy consumption, Patellofemoral pain syndrome, Plantar pressure distribution, Young, Walking

Purpose: The aim of the present study was to investigate the difference indynamic plantar pressure distribution changes in patients with degenerativeknee arthrosis before and eight months after total knee arthroplasty (TKA)surgery. Materials andMethods: Patients with end stage gonarthrosisadmitted to our clinic for TKA constituted the study group. An EMED SF-4pressure sensitive platform was used to quantify the barefoot plantar pressuresof the participants’ feet. Stance phase duration (ms), total plantar pressure(N/cm2) and centre of pressure (CoP) patterns during gait were recordedpreoperatively and at 8th months postoperatively.Results: Fifteen knees of 13 patients who underwent primary TKA wereincluded in the study. Stance phase durations in the pre- and postoperativeperiods were 987 ms and 801.5 ms, respectively. Total plantar pressures in thepre- and postoperative periods were 1257.75 N/cm2 and 1436.0 N/cm2,respectively. The difference in mediolateral plantar area was 0.69% in favor oflateral side of feet in the preoperative period and changed to 5.17% in favorof medial.Conclusion: Forthe surgical realignment of the knee, the kinematic chain of the lower extremitymust be considered, and gait analysis will be helpful in deciding the type ofsurgical treatment., Amaç: Bu çalışmada dejeneratif diz artriti olan hastaların total dizprotezi (TDP) ameliyatı öncesi ve ameliyattan sekiz ay sonra ölçülen plantarbasınç ölçümlerini karşılaştırmayı amaçladık. Gereç veYöntem: Bu amaçla kliniğimizde gonartroz nedeniyleTDP uyguladığımız 13 hastanın 15 dizine, ameliyat öncesi ve sonrası, en azsekiz ay sonra, EMED-SF plantar basınç dağılımı ölçüm sistemi kullanarakdinamik ayak tabanı basınç ölçümleri uyguladık. Tüm hastaların duruş fazısüreleri, toplam basınç değerleri ve COP (yürüme çizgisi) kullanılarak duruşfazında ayak basınçlarının mediale ve laterale yer değiştirmesi hesaplandı.Bulgular: Ameliyat öncesi 1257.75 N/cm2 olan toplam duruş fazı plantarbasınç, ameliyat sonrası 1436.0 N/cm2 ‘ye yükseldi. Bu fark istatistikselolarak düşük derecede anlamı olarak tespit edildi. Ameliyat öncesi 987ms olantoplam duruş fazı süresi ameliyat sonrasında 801.5ms’ye düşmüştür.Mediyolateral alan farkı ameliyat öncesi lateral lehine %0,69 iken ameliyatsonrası ölçümlerde bunun medial lehine %5.17 olarak değiştiği tespit edildi.Sonuç: Dejeneratif artritte ve TDP ameliyatlarında yürümeanalizi kullanılarak yapılan cerrahinin etkinliği ölçülebilmekte ve ileriçalışmalarla TDP uygulamalarının, hastaya özel planlanmasında, yararlıolacağına inanmaktayız.

Highlights ► Foot kinematics were compared between children with and without juvenile idiopathic arthritis. ► Gait measurements and ultrasound features were explored as measures of structure and function. ► Magnitude and timing parameters for foot kinetics and pressure distribution were similar. ► Foot function did not differ despite moderate foot impairments and disability levels., Purpose The objective of this study was to compare disease activity, impairments, disability, foot function and gait characteristics between a well described cohort of juvenile idiopathic arthritis (JIA) patients and normal healthy controls using a 7-segment foot model and three-dimensional gait analysis. Methods Fourteen patients with JIA (mean (standard deviation) age of 12.4 years (3.2)) and a history of foot disease and 10 healthy children (mean (standard deviation) age of 12.5 years (3.4)) underwent three-dimensional gait analysis and plantar pressure analysis to measure biomechanical foot function. Localised disease impact and foot-specific disease activity were determined using the juvenile arthritis foot disability index, rear- and forefoot deformity scores, and clinical and musculoskeletal ultrasound examinations respectively. Mean differences between groups with associated 95% confidence intervals were calculated using the t distribution. Results Mild-to-moderate foot impairments and disability but low levels of disease activity were detected in the JIA group. In comparison with healthy subjects, minor trends towards increased midfoot dorsiflexion and reduced lateral forefoot abduction within a 3–5° range were observed in patients with JIA. The magnitude and timing of remaining kinematic, kinetic and plantar pressure distribution variables during the stance phase were similar for both groups. Conclusion In children and adolescents with JIA, foot function as determined by a multi-segment foot model did not differ from that of normal age- and gender-matched subjects despite moderate foot impairments and disability scores. These findings may indicate that tight control of active foot disease may prevent joint destruction and associated structural and functional impairments.

Cutting movements in football (soccer) induce high loads on the anterior cruciate ligament in the knee. The injury risk is affected by the shoe-surface interaction. For the evaluation of different influencing factors of this interaction the TrakTester, a custom-made device, was used. To obtain significant results from testing ACL loading a realistic plantar pressure distribution in the shoe is required. Using the TrakTester several cutting movements were carried out using two different foot models with the resultant plantar pressure analysed with three different systems: The original foot model with Parotec insoles (24 integrated sensors; Paromed GmbH, Markt Neubeuern, Germany), the modified version of this foot model with Pedar-X insoles (99 sensors; novel GmbH, Munich, Germany) and the inflexible model was surveyed with the OpenGo science system (13 sensors, Moticon, Munich, Germany). For the inflexible model distinct angles between the lower leg and the surface were adjusted and the obtained plantar pressure distributions were analyzed. As the first version showed high pressures in the arch region, it was modified to reduce the load in this area. A second inflexible model induced the pressure in the heel and forefoot region. For various angles similar plantar pressure distributions were obtained. Highest pressures were applied on the medial side of the heel and forefoot with minor load in the arch region. This corresponds to literature data investigating cutting movements with subjects. Tests with the inflexible foot model achieved similar and realistic patterns of the plantar pressure distribution for different angles. This is an important precondition to obtain reproducible data for ACL loading during cutting movements.

Objective: Verify the variables of plantar pressure distribution of patients submitted to surgical procedure for calcaneal fracture, and correlate them with two different surgical approaches. Method: The authors studied 15 patients between 20 and 53 years of age (average 40.06 yrs.) who had intra-joint calcaneal fractures, submitted to surgical treatment by means of two different approaches: the lateral and the sinus tarsi. The authors checked the plantar pressure distribution by correlating these variables with the two different surgical approaches. The plantar pressure distribution was assessed using the Pedar System (Novel, Gmbh, Munich, Germany), by checking the maximum peak of the hindfoot and forefoot pressure on the affected and the normal sides. Results: the mean maximum pressure of the hindfoot plantigram in both approaches showed no statistical difference (t=0.11; p=0.91), as well as the mean maximum pressure of the forefoot plantigram (t=-0,48; p=0,64). Conclusion: The authors have concluded that there were no significant statistical differences between the average maximum peak of the hindfoot and forefoot pressure on the affected side as compared to the normal side, and these variables have showed no differences when compared to the surgical approach used.

This study aimed to use the plantar pressure insole for estimating the three-dimensional ground reaction force (GRF) as well as the frictional torque (T-F) during walking. Eleven subjects, six healthy and five patients with ankle disease participated in the study while wearing pressure insoles during several walking trials on a force-plate. The plantar pressure distribution was analyzed and 10 principal components of 24 regional pressure values with the stance time percentage (STP) were considered for GRF and T-F estimation. Both linear and non-linear approximators were used for estimating the GRF and T-F based on two learning strategies using intra-subject and inter-subjects data. The RMS error and the correlation coefficient between the approximators and the actual patterns obtained from force-plate were calculated. Our results showed better performance for non-linear approximation especially when the STP was considered as input. The least errors were observed for vertical force (4%) and anterior-posterior force (7.3%), while the medial-lateral force (11.3%) and frictional torque (14.7%) had higher errors. The result obtained for the patients showed higher error; nevertheless, when the data of the same patient were used for learning, the results were improved and in general slight differences with healthy subjects were observed. In conclusion, this study showed that ambulatory pressure insole with data normalization, an optimal choice of inputs and a well-trained nonlinear mapping function can estimate efficiently the three-dimensional ground reaction force and frictional torque in consecutive gait cycle without requiring a force-plate. (C) 2010 Elsevier B.V. All rights reserved.

Objective The purpose of our study was to compare plantar pressure asymmetry and step-to-step reproducibility in both able-bodied persons and two groups of hemiplegics. The relevance of the research was to determine the efficiency of asymmetry and reproducibility as indexes for diagnosis and rehabilitation processes. Material and method This study comprised 31 healthy young subjects and 20 young subjects suffering from cerebral palsy hemiplegia assigned to two groups of 10 subjects according to the severity of their musculoskeletal disorders. The peaks of plantar pressure and the time to peak pressure were recorded with an in-shoe measurement system. The intra-individual coefficient of variability was calculated to indicate the consistency of plantar pressure during walking and to define gait stability. The effect size was computed to quantify the asymmetry and measurements were conducted at eight footprint locations. Results Results indicated few differences in step-to-step reproducibility between the healthy group and the less spastic group while the most affected group showed a more asymmetrical and unstable gait. Conclusion From the concept of self-optimisation and depending on the neuromotor disorders the organism could make priorities based on pain, mobility, stability or energy expenditure to develop the best gait auto-optimisation.

This paper introduces the design and development of a novel pressure-sensitive foot insole for real-time monitoring of plantar pressure distribution during walking. The device consists of a flexible insole with 64 pressure-sensitive elements and an integrated electronic board for high-frequency data acquisition, pre-filtering, and wireless transmission to a remote data computing/storing unit. The pressure-sensitive technology is based on an optoelectronic technology developed at Scuola Superiore Sant’Anna. The insole is a low-cost and low-power battery-powered device. The design and development of the device is presented along with its experimental characterization and validation with healthy subjects performing a task of walking at different speeds, and benchmarked against an instrumented force platform.

WalkinSense is a new device designed to monitor walking. The aim of this study was to measure the accuracy and repeatability of the gait analysis performed by the WalkinSense system. Descriptions of values recorded by WalkinSense depicting typical gait in adults are also presented. A bench experiment using the Trublu calibration device was conducted to statically test the WalkinSense. Following this, a dynamic test was carried out overlapping the WalkinSense and the Pedar insoles in 40 healthy participants during walking. Pressure peak, pressure peak time, pressure-time integral, and mean pressure at eight-foot regions were calculated. In the bench experiments, the repeatability (i) among the WalkinSense sensors (within), (ii) between two WalkinSense devices, and (iii) between the WalkinSense and the Trublu devices was excellent. In the dynamic tests, the repeatability of the WalkinSense (i) between stances in the same trial (within-trial) and (ii) between trials was also excellent (ICC > 0.90). When the eight-foot regions were analyzed separately, the within-trial and between-trials repeatability was good-to-excellent in 88% (ICC > 0.80) of the data and fair in 11%. In short, the data suggest that the WalkinSense has good-to-excellent levels of accuracy and repeatability for plantar pressure variables.