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No description available.

Background: Despite a lack of consensus on its utility, clinicians have traditionally relied on plantar pressure (PP) to predict ulcer risk and prescribe interventions in individuals with diabetic peripheral neuropathy (DPN). Joint kinematics and kinetics have the potential to contribute to DPN assessment and treatment, however previous studies have not accounted for walking speed nor integrated a full-body analysis with a detailed foot model. Purpose: To assess PP and gait alterations in DPN by controlling walking speed and incorporating a multisegment foot model into a full-body gait analysis. We hypothesize that hip and ankle kinetics will be altered consistent with distal muscle weakness. Methods: Ten subjects with DPN (height: 178.79 ± 8.55 cm, weight: 108.78 ± 16.67 kg, age: 61.5 ± 13.53 years), and 10 healthy matched controls (height: 180 ± 6.37 cm, weight: 92.87 ± 14.5 kg, age: 59.4 ± 7.5 years) participated in this cross-sectional study. Fifty-six reflective markers were attached to each subject according to a full-body model, including a multisegment foot. Subjects walked at a controlled speed (1 m/s) while plantar pressure, kinematic and kinetic data were collected. Functional data analysis was used to compare kinematic and kinetic data between groups, while independent t-tests and a Benjamini-Hochburg procedure was used to compare plantar pressure and joint work metrics. Results: Individuals with DPN presented with a delayed transition from hip extension to hip flexion moment and a decrease in peak hip flexion moment. There were no major changes found at the knee. There was an increase in peak dorsiflexion angle and delayed power generation in both the ankle and midtarsal joints. DPN subjects also showed a decreased midtarsal positive work. The only significant PP metric found was a decrease in peak PP under the lateral toes. Conclusion: Findings demonstrated that individuals with DPN use a hip compensation mechanism to overcome distal muscle weakness. Ankle and midfoot alterations are consistent with muscle weakness, requiring proximal compensations. Joint mechanics were more informative than PP measurements and may provide additional insight into DPN assessment and treatment.

Hallux valgus and hallux limitus are two common foot pathologies that may require surgical intervention. While the modified Austin bunionectomy and the Youngswick osteotomy/cheilectomy respectively, are often used to correct these conditions, insufficient research has been published regarding the effects of these procedures on plantar pressure distribution of the foot. This thesis involves a series of six studies investigating topics relating to radiographic measurements and plantar pressure distribution over a two-year period, in normal feet and in hallux valgus and hallux limitus feet before and after corrective surgery.A review of the literature is presented relating to the development of plantar pressure measurement technology, the aetiology and surgical management of hallux valgus and hallux limitus, the reliability of the EMED system used in the studies, and the related clinical uses of plantar pressure measurement.An initial study was designed to investigate the reliability measurements using a simplified two-step method of data collection as compared to the traditional mid-gait technique of ten normal asymptomatic subjects. Intra-class correlation coefficients were calculated and compared for the pressure variables of contact area, contact time, maximum force and peak pressure of ten regions of the foot.A study to determine normal reference range values for the EMED-SF system was then conducted using thirty healthy subjects and the two-step method of data collection. Descriptive statistical reporting of peak pressure, mean pressure and pressure-time- integrals were presented for ten regions of the foot.Three related studies on radiographic and plantar pressure measurement differences, and their relationships were made using thirty normal, hallux valgus and hallux limitus feet. Various angular and linear radiographic measurements were tested for intra-rater ++ / reliability of measurement and pressure variables of peak pressure, mean pressure and pressure-time-integral of 10 regions of the foot were recorded and one way analysis of variance employed to assess any significant differences.Finally, two independent two-year prospective studies were designed to investigate the effects of the modified Austin bunionectomy for hallux valgus and the Youngswick osteotomy/cheilectomy for hallux limitus on plantar pressure distribution of the forefoot. In addition, fundamental radiographic measurement changes of the forefoot of hallux valgus subjects and range of motion changes of the first metatarsophalangeal joint of hallux limitus subjects were conducted. Thirty-six healthy volunteers acted as control subjects, 31 subjects (44 feet) with hallux valgus and 17 subjects (23 feet) with hallux limitus were included in the study. Using an EMED-SF system, plantar pressure variables of peak pressure, pressure-time-integral, contact time, maximum force and force-time-integral were recorded at six regions of the forefoot, pre-operation and repeated at three, six, 12, 18 and 24-months post-operation for surgical subjects. Control subjects were tested at zero and 24-months. Descriptive statistics, multivariate and univariate analysis of variance with contrasts, t-tests of significance and correlations between certain measurement parameters were used in the analysis of the results.The findings of these studies suggest that the two-step method of data collection of plantar pressure measurements is more reliable that the traditional mid-gait technique for most pressure variables. Consequently, the two-step method was employed as the preferred method of data collection in this series of studies.With respect to radiographic differences between normal, hallux valgus and hallux limitus, it appears that hallux valgus feet have significant increases in ++ / metatarsus primus varus and first metatarsal protrusion distance, while hallux limitus feet have increased hallux abductus interphalangeal angles. Comparison of pressure variables between each group demonstrate hallux valgus feet have a medial localisation of peak pressure beneath the first, second and third metatarsal heads, suggesting that hyperpronation of the foot is associated with the development of hallux valgus. Hallux limitus feet on the other hand, show increased pressure beneath the hallux, third and fourth metatarsals and lesser toes, indicating a more lateral locus of pressure loading, suggestive -of the foot functioning in a more supinated position. No significant relationship was found between any radiographic parameter and pressure variable tested in either group of subjects.Plantar pressure measurement changes show the greatest variation during the initial three to six months following surgical treatment of hallux valgus and hallux limitus. The Youngswick osteotomy/cheilectomy for the treatment of hallux limitus produces near-normal range of motion of the first metatarsophalangeal joint. Pressures of the first metatarsal head remain relatively constant over the period of measurement, while a significant reduction of the hallux and lateral metatarsals were noted, related to increased dorsiflexion of the hallux. Pressures of the second metatarsal head remained significantly above pre-operation levels. The modified Austin bunionectomy for the treatment of hallux valgus produced 24-month radiographic changes consistent with accepted values. Pressure variables of the hallux reduced to normal values, with the first metatarsal head demonstrating an initial significant decrease and subsequent increase by twelve months post-operation to remain with the second metatarsal head at relatively similar values to pre-operation measurements.The research demonstrates ++ / the two-step method of data collection is a viable means of obtaining reliable plantar pressure measurement data in the clinical situation. The investigations into radiographic and plantar pressure distribution indicate that structural radiographic and functional differences exist between normal, hallux valgus and hallux limitus feet. However, no relationship could be found between any of the radiographic parameters and pressure variables tested.The modified Austin bunionectomy for hallux valgus significantly reduced fundamental radiographic measurements to accepted post-operative values, while the Youngswick procedure for hallux limitus significantly increased the amount of post-operative dorsiflexion of the hallux to normal values. The research demonstrates that immediate and longer-term functional changes to the forefoot occur following the surgical treatment of hallux valgus and hallux limitus, however plantar pressure measurements do not return to normal values. No correlation was found between plantar pressure measurements and post- operative radiographic measurements in the hallux valgus group. However, the increased amount of dorsiflexion of the hallux post-operatively in the hallux limitus group was correlated with reduced lateral loading of the forefoot. Post-operation changes of plantar pressure distribution indicate that the rehabilitative period required to achieve stable foot function is between twelve to eighteen months. Furthermore, plantar pressure measurement technology offers the clinician a useful tool to monitor foot function prior to and following therapeutic intervention.

No description available.

Adult Acquired Flatfoot Deformity (AAFD) is a progressive disease characterized by mechanical degeneration of the soft tissue structure in the arch of the foot that leads to changes in joint alignment. Surgical intervention commonly via tendon transfer and bony osteotomy is used to restore arch architecture, however there is a lack of quantitative assessments that measure the success of the surgical correction in vivo. Using plantar pressures via Tekscan® HR Mat and surveys (SF-36, FAOS), pre-operative and post-operative measures for six participants were defined, analyzed and compared. A paired t-test showed significant lateral shift for percent body weight during walking postoperativelyin the forefoot and midfoot regions. However, arch index measurement showed no significant change. The FAOS survey score also improved statistically postoperatively. The surgical correction was successful as deemed by some of these quantitative and qualitative measures.

1 Abstract: The aim of this study quantify and compare the differences in the dynamics of foot movement compared with static in adulthood and old age, focusing on the midstance phase. A secondary objective is to outline the relationship with the angular distribution of pressure on the sole. For measurements two measuring methods were used. The kinematic analysis named Qualysis was used as a main method and system of plantar pressure insoles Pedar X as a complementary method. The difference in measured distance of 1-MP calcaneus, 5MP - calcaneus and pronate angle of calcaneus was prooved using the statistical calculation, which confirmed the hypothesis of half clear a significant degree. Subsequently, the changes were further specified using the results of the distribution of maximum force and contact time of the soles.

Title: Quantification of plantar pressure distribution and geometry of forefoot according to the character of shoes Objectives: The main purpose of this thesis is to describe and verify the changes in the sole of the foot according to the style of shoe which are manifested by changes in the values of the maximum pressure, contact area, contact time and changes in pressure time integral. The next object is to verify the changes in forefoot geometry according to the style of shoes. Methodology: The sample consisted of 6 healthy women of average age 25 ± 1 year. All study participants reported wearing high-heeled shoes occasionally which means not more than twice per week. The measurement was realized with the Pedar-X in-shoe pressure measurement system (Novel) and motion capture system Qualisys. Results were analysed statistically using Wilcoxon test. Statistical significance was set at p < 0,05. Results: From the received data we could find out the changes that footwear causes in healthy people. The findings of this study indicate that the use of different style of shoes affect all measured parameters such as maximum pressure, contact area, contact time and pressure time integral.From the experiment evaluation, it is clear that the style of shoes may also affect the geometry of forefoot. Keywords:...

Diabetic foot ulceration (DFU) is a known major complication of diabetes mellitus which contributes to lower extremities amputation. This study aimed to investigate the use of interventional devices either as a preventative or therapeutic strategy to improve clinical management of this pathology, as well as investigating the impaired function of endothelial progenitor cells in the diabetic condition. The first element targeted plantar callus formation among diabetic neuropathic (NRP) patients through the use of a SurroSenseRxTM biofeedback device. Reducing foot pressure with improved walking strategy in the 6 months study in diabetic neuropathy patients (n=20) appeared to minimise the size of non-ulcerative plantar callus (p < 0.05), potentially reducing future ulcer recurrence. The 2nd study focused on the use of a GekoTM electrical stimulation device to enhance DFU healing in 24 patients. Wounds were characterised as being neuroischaemic (NRI) or neuropathic (NRP) based on standard parameters adopted in the Manchester diabetes clinic. The device was worn by 11 intervention subjects and compared to 13 controls without any electrical stimulus. Results suggested healing and wound closure have potentially increased in participants with electrical stimulation. In addition, Neuropathy Disability Score (NDS) was improved among intervention patients compared to control (p < 0.0001). The 3rd, in vitro and mechanistic study focuses on the outgrowth of endothelial cells (OECs), abnormal angiogenic responses and inflammatory microenvironment which could contribute to impaired wound healing in diabetic patients. OECs were isolated from diabetic patients and healthy controls (HCs), characterised by immunohistochemistry and Polymerase Chain Reaction (PCR). The functions of the three OEC groups from NRI, NRP diabetic patients and healthy controls respectively were compared using in vitro proliferation, transwell migration and wound healing scratch assays, together with matrigel tube formation assays. Scratch assays showed 100% closure in HCs over 24 hours, while 86.6% closure was apparent in NRI vs 38.1% in NRP. Seahorse mitochondrial stress test was conducted and demonstrated mitochondrial dysfunction in NRP vs NRI vs HCs (p < 0.05). Western blot analysis showed a lack of ERK phosphorylation by NRP OECs and an up-regulation of plasma inflammatory cytokines (TNFa and IL-6) in diabetic samples vs HC (p < 0.0001), while the angiogenic factors ang-2, FGF-2, VEGF-D, HGF and IL-8, and nitric oxide bioavailability were all significantly reduced in diabetic samples vs HC (p < 0.05). The functional defects of the diabetic OECs were partially restored through glycomimetic (synthesis compounds for endothelial damage protection) treatment (p < 0.05). In summary, this study has highlighted areas worthy of future development both in terms of preventative and therapeutic strategies. With improvements in digital technology and the need to empower patients to take responsibility of their health and well-being as well as greater understanding of the cellular and molecular biological repair processes that may be exploited, there may be potentials to reduce the risk of future ulceration among patients using these novel approaches in the future.

Este trabalho desenvolve uma metodologia de otimização de solado de calçados utilizando simulações estáticas de elementos finitos. Diversas medições foram realizadas em laboratório para obter dados que caracterizem a pisada humana. As medições realizadas foram das seguintes grandezas: força de reação, pressão na interface pé-solado e medição de ângulo relativo entre pé e perna. Os resultados dessa medição foram utilizados para definir e verificar um modelo 3D de elementos finitos. A geometria utilizada para gerar a malha de elementos foi construída a partir de imagens de tomografia computadorizada que passaram pelo processo de reconstrução 3D e suavização do contorno. As propriedades dos materiais utilizadas na simulação foram obtidas na literatura para a parte óssea e tecidos moles do pé. As propriedades do solado do calçado foram obtidas através de ensaios e ajuste de curvas de modelos hiperelásticos. A simulação apresentou resultados coerentes com a medição, validando o modelo para ser utilizado na otimização do solado. O solado foi otimizado para um parâmetro de geometria e um do material, objetivando a redução de picos de pressão plantar nas regiões do calcanhar e abaixo dos metatarsos em dois instantes de tempo mais representativos da pisada. A metodologia proposta é uma solução atraente para eliminação de fatores subjetivos na avaliação de um calçado e redução de custo de fabricação de protótipos, bem como para melhorar aspectos relacionados à conforto e desempenho. / This paperwork develops a optimization methodology for shoe sole using finite element static simulation. Several experimental measurements were done to characterize human gait. The measured variables were: reaction force, plantar pressure and foot-leg angle. The results of experimental measurement were used to define and verify a 3D finite element model. Computerized tomography images were used to create the geometry that served as base for finite element mesher. The images were first used in 3D reconstruction and therefore boundary suavization. Bone and soft tissues properties were defined from literature. Sole material properties were defined with rubber experiment and hyperelastic model fit. Finite element model proved to be valid due to results similar to experimental tests. Sole design were optimized for one geometry parameter and one material parameter. The main goal were peek pressure reduction in heel and metatarsal head region using two representative time step. Te proposed methodology is attractive due to elimination of subjective factors in comfort evaluation and reduction of prototypes manufacturing.