The use of computational modeling is an increasingly commonplace technique for the investigation of biomechanics in intact and pathological musculoskeletal systems. Moreover, given the robust and repeatable nature of computer simulation and the prevalence of software techniques for accurate 3-D reconstructions of tissues, the predictive power of these models has increased dramatically. However, there are no patient-specific kinematic models whose function is dictated solely by physiologic soft-tissue constraints, articular shape and contact, and without idealized joint approximations. Moreover, very few models have attempted to predict surgical effects combined with postoperative validation of those predictions. Given this, it is not surprising that the area of foot/ankle modeling has been especially underserved. Thus, we chose to investigate the pre- and postoperative kinematics of Adult Acquired Flatfoot Deformity (AAFD) across a cohort of clinically diagnosed sufferers. AAFD was chosen as it is a chronic and degenerative disease wherein degradation of soft-tissue supporters of the medial arch eventually cause gross malalignment in the mid- and hindfoot, along with significant pain and dysfunction. Also, while planar radiographs are still used to diagnose and stage the disease, it is widely acknowledged that these 2-D measures fail to fully describe the 3-D nature of AAFD. Thus, a population of six patient-specific rigid-body computational models was developed using the commercially available software packages Mimics® and SolidWorks® in order to investigate foot function in patients with diagnosed Stage IIb AAFD. Each model was created from patient-specific sub-millimeter MRI scans, loaded with body weight, individualized muscle forces, and ligament forces, in single leg stance. The predicted model kinematics were validated pre- and postoperatively using clinically utilized radiographic angle distance measures as well as plantar force distributions. The models were then further exploited to predict additional biomechanical parameters such as articular contact force and soft-tissue strain, as well as the effect of hypothetical surgical interventions. Subsequently, kinematic simulations demonstrated that the models were able to accurately predict foot/ankle motion in agreement with their respective patients. Additionally, changes in joint contact force and ligament strain observed across surgical states further elucidate the complex biomechanical underpinnings of foot and ankle function.

Computational joint models provide insight into the biomechanical function of human joints. Through both deformable and rigid body modeling, the structure-function relationship governing joint behavior is better understood, and subsequently, knowledge regarding normal, diseased, and/or injured function is garnered. Given the utility of these computational models, it is imperative to supply them with appropriate inputs such that model function is representative of true joint function. In these models, Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT) scans and literature inform the bony anatomy and mechanical properties of muscle and ligamentous tissues, respectively. In the case of the latter, literature reports a wide range of values or average values with large standard deviations due to the inability to measure the mechanical properties of soft tissues in vivo. This makes it difficult to determine which values within the published literature to assign to computational models, especially patient-specific models. Therefore, while the use of published literature serves as a reasonable first approach to set up a computational model, a means of improving the supplied input data was sought. This work details the application of artificial neural networks (ANNs), specifically feedforward and radial basis function networks, to the optimization of ligament stiffnesses for the improved performance of pre- and post-operative, patient-specific foot/ankle computational models. ANNs are mathematical models that utilize learning rules to determine relationships between known sets of inputs and outputs. Using knowledge gained from these training data, the ANN may then predict outputs for similar, never‑before-seen inputs. Here, an optimal network of each ANN type was found, per mean square error and correlation data, and then both networks were used to predict optimal ligament stiffnesses corresponding to a single patient’s radiographic measurements. Both sets of predictions were ultimately supplied to the patient-specific computational models, and the resulting kinematics illustrated an improvement over the existing models that utilized literature-assigned stiffnesses. This research demonstrated that neural networks are a viable means to hone in on ligament stiffnesses for the overall objective of improving the predictive ability of a patient-specific computational model.

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: Use of orthopaedic insoles in childhood Supervisor: PhDr. Tereza Nováková, PhD. Problem definition: The importance of the longitudinal arch is one of the most discussed topics in orthopaedics. Similarly important is the indication of orthopaedic insoles for flat feet especially in children. Experts have different opinions about what age insoles should be prescribed, and if their use is beneficial. So far, a clearly defined boundary has not been established between real pathology and a flexible flat foot formed on the basis of hypermobility which is to some extent physiological in childhood. Aim: To compare the plantograms of groups of six-year-old children with diagnosed pes planus/planovalgus before and after six month (or more) use of, individually prepared, insoles. To compare the results with a group of children that did not have insoles prescribed and on this basis to judge whether there was change (improvement) that can be proven with the use of a plantogram. Method: Two groups of six-year-old subjects were formed. The experimental group: subjects with prescribed orthopaedic insoles, and the control group: subjects that were not prescribed orthopaedic insoles. Plantograms were evaluated with the help of the Chippaux-Šmiřák index method. Conclusion: The results indicate a partial...

Introduction: Spinocerebellar ataxia (SCA) is currently defined as a group of diseases with progressive cerebellar syndrome, which manifests distinctively by ataxic stance and gait. In patients with SCA, deterioration of postural control occurs due to changes of pathophysiological degenerative nervous system. Control of postural stability is significantly influenced by somatosensory afferentation of soft tissue of foot. The work objective is to determine the effect of deep foot massage on postural stability in the group of patients and to compare obtained results with experiments without deep foot massage. Methods: Seven patients of the Clinic Rehabilitation at the Faculty Hospital, Prague Motol (average age 51.9 ± 13.9 years, 5 men, and 2 women) with SCA and clinical signs of cerebellar ataxia were participated in this study. All patients were examined using posturography before and after application of deep foot massage. Measurements were conducted on a firm surface, foam pad with open and closed eyes. Length of COP trajectory, COP area and COP velocity were measured. Results: Significantly lower values of the length and COP velocity were found on the foam pad with closed eyes, when the deep foot massage was applied. Experiments without applications of the deep foot massage did not show any...

Title Comparison of selected parameters of function and shape of the foot in volleyball and beach volleyball women players Objectives The goal of this thesis is to find out if there are differences in chosen parameters for competitively playing volleyball and beach volleyball women players. Compare the influence of the sports footwear and hard surface court on the shape and function of the foot with the bare foot on the sand in technically similar sports. Methods The research involved 10 women playing volleyball and 10 women playing beach volleyball. All the players were 19 - 34 years old and all were regularly playing at competitive level. Selected monitored parameters were the quality of perception of sensation in the foot, foot arch shape evaluated by using plantogram and examination postural stability by using the Véle test. The test results were evaluated in both sports separately and then compared with each other. Results The results of this thesis show better readings in all investigated tests in both lower limbs at beach volleyball women players. Only in the case of the shape of the foot arch test on the left foot was the result statistically significant. Other selected parameters in shape and function of beach volleyball women players feet did not show plausible statistical difference....

Title: Evaluation plantogram and range of motion of the joints of the lower extremity with hallux valgus deformity. Objectives: The aim of my thesis, "Evaluation plantogram and range of motion of the joints of the lower extremity with hallux valgus deformity" is a statistical comparison of the aspects of the lower limbs in healthy subjects and people affected by hallux valgus deformity. It will be a comparison of the measured values, such as the degree of hallux valgus angle, range of motion of the hip joint to spin, Q - angle of the lower limb, position of hocks and strained soles. Methods: Plantographic evaluation of the strain on the soles on Podoscope, goniometry, photography, plantographic diagnostic method - Chippaux - a Šmírák and Sztriter - Godunov. Results: During this research, I observed twenty seven individuals. Five individuals had hallux valgus deformity, fourteen individuals had valgus position of the thumb and seven individuals had no deformity. In the course of evaluating plantogram and range of motion of the joints of the lower limb with hallux valgus deformity I observed degree of flat. This statement was confirmed at a significant level of p = 0.01 for both legs. Unfortunately in case of individuals with mild hallux valgus deformity, the proximo-distal, or disto-proximal...

The aim of this thesis was to determine the biomechanical adaptations made by active unilateral trans-tibial amputees when they used a prosthesis incorporating a hydraulically-damped, articulating ankle-foot device compared to non-hydraulically attached devices. Kinematic and kinetic data were recorded while participants ambulated over a flat and level surface at their customary walking speeds and at speeds they perceived to be faster and slower using the hydraulic device and their habitual foot. Use of the hydraulic device resulted in increases in self-selected walking speeds with a simultaneous reduction in intact-limb work per meter travelled. Use of the device also attenuated inappropriate fluctuations in the centre-of-pressure trajectory beneath the prosthetic foot and facilitated increased residual-knee loading-response flexion and prosthetic-limb load bearing during stance. These changes occurred despite the hydraulic device absorbing more, and returning less, energy than the participants’ habitual ankle-foot devices. The changes were present across all walking speeds but were greatest at customary walking speeds. The findings suggest that a hydraulic ankle-foot device has mechanical benefits, during overground gait, for active unilateral trans-tibial amputees compared to other attachment methods. The findings also highlight that prosthetic ankle-foot device ‘performance’ can be evaluated using surrogate measures and without modelling an ‘ankle joint’ on the prosthetic limb.

Background: Hallux valgus (HV) is one of the most common foot deformities. Considering the fact that 23% of adults develop such condition during their lifetime, understanding HV is badly needed. Plantar pressure technologies are used widely for determination of biomechanical changes in foot during walking. There are already published claims relating to the pressure distribution of HV condition. Association of HV to sole pressure widely presented as a means of identifying such condition. Methods: plantar pressure patterns can be linked to the deformity progression or existence, extracting some patterns out of force measurements can be beneficial in recognizing the patients with and without deformity. The dynamic changes of the forces that applied to the fore-foot in volunteers with and without HV when they walked at self-selected and fast speeds were examined. Furthermore, Markovian chain transfer matrices were used to obtain the transfer coefficient of the force among five metatarsals. Another method was to measure the lateral flexibility of the 1st metatarsal joint as an indication of HV deformity by Motion Capture cameras. Finally, two 3D feet models of HV and non-HV volunteers were made in Mimics software and then in FEA (finite element analysis) the stress distribution under the foot was validated with the experiments. Results: The higher forces were observed under the 2nd, 3rd and 1st metatarsal heads in both speeds but the results obtained were significantly different among groups and in fast speed and under 3rd and 1st metatarsals in self-selected speed. In this study the use of Markovian transfer matrices as a means of characterising the gait pattern is new and novel. It was intended that highest coefficients of the matrix would indicate the existence of HV, however studies showed that the biggest difference between HV and non HV patients was the scatter of the coefficients which shown to give very strong indication of the existence of HV. It was shown by kinematic studies and also it was found that the 1st metatarsal joint was significantly more flexible in HV patients compared to non–HV individuals. Finally FEA studies has shown that in the 3D feet models of both volunteers (with and without HV), the highest stress was under the heal area and then transfers towards fore-foot area. In patient with HV the higher force were seen under the 1st to 3rd metatarsal heads compare to non-HV individual and each model was validated its related experiments. Conclusion: it was observed that there was a significant variability of pressure distribution of the same individual from one trial to another indicating that getting consistent pressure pattern is an important hurdle to overcome in our studies, raised loading is observed on Metatarsal 2, 3 and 1 in HV patients and it was possible to give statistical significance to these findings. In this thesis, it was intended to obtain early diagnostics of HV condition and much work was put in this, however outcome was not conclusive. However it was possible to distinguish HV form non-HV volunteers from the scatter characteristics of the transfer pattern. Investigation of the 1st metatarsal joint laxity of non-HV and HV patients revealed that HV individuals were significantly higher compared to non–HV volunteers and this can be used as an indication of HV existence. Finally, the 3D models show that FEA is a reliable tool as the FEA study showed good correlation with the experimental results.

Löpning är en av de största fysiska aktiviteterna runt om i världen. Det räknas med att 37-56 % av alla som löper någon gång drabbas av en skada i samband med löpningen. Studiens syfte är att undersöka effekten av olika dämpningsmaterial, drop samt motion-kontroll av löparskor på skadefrekvens i samband med pronation och supination under löpning. Studien gjordes som en litteraturstudie där 11 vetenskapliga artiklar ingick i studien. Resultatet visar att motion-kontroll skor rekommenderas till pronerande löpare och neutrala skor till supinerande eller neutrala löpare. Minskat drop leder till minskad skaderisk. Framfotslöpning är att föredra jämfört med häl till tå löpning. En mjuk sula är bättre vid kortdistans och en hårdare sula vid långdistans. EVA material visade på en bättre återhämtningseffekt än TPU.