|
|
Gait analysis of female basketball players
Deličová, Tereza ; Vilímek, Miloslav (advisor) ; Horák, Zdeněk (referee)
Title: Gait analysis of female basketball players Objectives: The main objective of this thesis is to perform gait analysis using Qualisys and Kistler systems in long time female basketball players and population that does not engage in any regular sports activity on competitive level. Selected spatiotemporal, kinematic and kinetic gait parameters are compared between measured groups. Methods: 20 female probands participated in this experimental study. Tested group consists of 10 long time female basketball players between ages of 21 and 29 (mean age of 24,5). Control group consists of 10 female probands between ages of 24 and 25 (mean age of 24,5) that do not engage in any competitive sport on regular basis. Qualisys Motion Capture system was used to gather 3D kinematic gait data. Ground reaction forces were measured by using Kistler force plates. Data was obtained by both systems at the same time. Evaluated gait parameters were walking speed, step length, pelvic and shoulder rotation range of motion in transversal plane, CG of foot range of motion and all ground reaction forces components. Two-sample t-test and Mann-Whitney U test with significance level of 0,05 were used for statistical analysis of obtained data. Results: Results of this study demonstrate that long time engagement in...
|
|
|
An investigation of friction and lubrication of coated hip joint replacement
Balcárek, Ondřej ; Horák, Zdeněk (referee) ; Nečas, David (advisor)
The thesis focused on studying the effects of a new hydrogel coating and material combinations on the coefficient of friction and formation of lubricating film in the conformal contact of hip joint replacement. Experiments were conducted using a ball-on-cup configuration with a hip pendulum simulator. The formation of the lubricating film was observed using fluorescence microscopy. The results showed that the application of the coating did not have a clear impact on the coefficient of friction. However, for pairs with a coated cup, there was a reduction in CoF by approximately 20%. Generally, lower friction was observed when using a ceramic joint head. Surprisingly, even more interesting results were obtained in the lubrication analysis, where the use of metal heads led to a reduction in the thickness of the lubricating layer. Ceramic pairs exhibited very stable behavior. In addition to friction and lubrication, the topography of the implants was further evaluated, and their wettability was analysed. Although the polymer coating was expected to be highly hydrophilic, the surface properties were only slightly influenced, which partly explains why there was no significant improvement in the tribological behavior of the replacement. As the coating applied is already patented and its effectiveness in reducing wear has been clearly demonstrated, it is appropriate to investigate this issue further, with more attention being paid to long-term experiments. Based on the obtained data, it appears that the short-term benefits of the coating are practically negligible. However, it is important to highlight that, except for minor exceptions, the application of the coating did not lead to a deterioration of properties, which is a significant outcome of this work.
|
|
|
Design of a simulator for studying eye friction and lubrication
Snopek, Lukáš ; Horák, Zdeněk (referee) ; Vrbka, Martin (advisor)
This work deals with the design of a tribometer, which simulates the interaction between the human eye and the eyelid, and simultaneously measures the friction between them and the thickness of the tear film. The tribometer will be used for research and development of artificial tears based on hyaluronic acid. The aim of the work was to design experimental conditions, conceptual and design solutions, as well as to ensure the production, assembly, and validation of the device. The experimental conditions were determined based on critical research. Four different conceptual solutions were proposed, of which two were selected for further development in the design solution. Based on the engineering documentation, the production of non-standardized components and assembly were ensured. Validation experiments demonstrated that the simulator enables the measurement of friction and tear film thickness at the contact area under the desired conditions, with both conforming and non-conforming types of contact. The contribution of this work lies in the construction of a new device that allows for measuring the coefficient of friction and film thickness during conforming contact, offering new opportunities in the study of human eye biotribology.
|
|
|
Influence of viscosupplementation on cartilage lubrication
Ondra, Martin ; Horák, Zdeněk (referee) ; Ranuša, Matúš (advisor)
This work deal with the determination of the effect of viscosupplementation on the lubrication of articular cartilage in the beginning phase of osteoarthritis. This effect was evaluated based on the development of CoF measured by a tribometer in configuration pin-on-plate. The tribological model of incipient osteoarthritis was simulated by using two articular cartilages lubricated with osteoarthritic synovial fluid to which viscosupplementation agents were added. These preparations differed mainly in cross-linking and molecular weight of hyaluronic acid (HA). Measurements have shown that viscosupplementation may be effective in the beginning phase of osteoarthritis. The efficacy of viscosupplementation preparations with cross-linking HA was significantly higher compared to the efficacy of viscosupplementation preparations without cross-linking. These results support the use of viscosupplementation to delay the advanced stage of osteoarthritis.
|
|
|
Analysis of muscle activity during steering wheel movement
Dostálová, Veronika ; Vilímek, Miloslav (advisor) ; Horák, Zdeněk (referee)
❆❜str❛❝t ❚✐t❧❡✿ ❆♥❛❧②s✐s ♦❢ ♠✉s❝❧❡ ❛❝t✐✈✐t② ❞✉r✐♥❣ st❡❡r✐♥❣ ✇❤❡❡❧ ♠♦✈❡♠❡♥t ❖❜❥❡❝t✐✈❡s✿ ❚❤❡ ❛✐♠ ♦❢ t❤✐s t❤❡s✐s ✐s t♦ ♣r♦❝❡ss ❛♥ ❛✉t♦♠♦t✐✈❡ ❡r❣♦♥♦♠② ✐ss✉❡✳ ❋✉t❤❡r♠♦r❡✱ t♦ ❛♥❛❧②s❡ ✉♣♣❡r ❡①tr❡♠✐t② ♠♦✈❡♠❡♥t ❛♥❞ ❡❧❡❝tr✐❝❛❧ ❛❝t✐✈✐t② ♦❢ s♣❡✲ ❝✐✜❡❞ s❤♦✉❧❞❡r ♠✉s❝❧❡s ❞✉r✐♥❣ st❡❡r✐♥❣ ✇❤❡❡❧ ♠♦✈❡♠❡♥t ✇✐t❤ ❛ ❞✐✛❡r❡♥t ❤❛♥❞ ♣❧❛❝❡♠❡♥t✳ ❆♥♦t❤❡r ❛✐♠ ✐s t♦ ❝♦♠♣❛r❡ ♠❡❛s✉rr❡❞ ❡❧❡❝tr♦♠②♦❣r❛♣❤✐❝ ❞❛t❛ ✇✐t❤ ❛♥ ♦♣t✐♠❛❧ r❛♥❣❡ ♦❢ ♠✉s❝❧❡ ❛❝t✐✈✐t② ❞✉r✐♥❣ r❡♣❡t✐t✐✈❡ t❛s❦s✳ ▼❡t❤♦❞s✿ ❚❤❡ t❤❡s✐s ❤❛s ❛ ❝❤❛r❛❝t❡r ♦❢ ❛ ♣✐❧♦t st✉❞②✳ ❚❡♦r❡t✐❝❛❧ ❜❛s✐s ❤❛s ❜❡❡♥ ♦❜t❛✐♥❡❞ ❜② ❛ r❡✈✐❡✇ ♦❢ ❧✐t❡r❛t✉r❡ ❞❡❛❧ ✇✐t❤ s✐♠✐❧❛r q✉❡st✐♦♥s✳ ❊①♣❡r✐♠❡♥t❛❧ ♣❛rt ❤❛s ❜❡❡♥ ❝♦♥❝❡r♥❡❞ ✇✐t❤ ❡❧❡❝tr✐❝❛❧ ❛❝t✐✈✐t② ♦❢ s♣❡❝✐✜❡❞ s❤♦✉❧❞❡r ♠✉s❝❧❡s ❛♥❞ ♠♦t✐✲ ♦♥ ❛♥❛❧②s✐s ♦❢ ✉♣♣❡r ❡①tr❡♠✐t② ❞✉r✐♥❣ ❝♦♥tr❛❧❛t❡r❛❧ ❛♥❞ ✐♣s✐❧❛t❡r❛❧ st❡❡r✐♥❣ ✇❤❡❡❧ ♠♦✈❡♠❡♥t ✇✐t❤ ❛ ❞✐✛❡r❡♥t ❤❛♥❞ ♣❧❛❝❡♠❡♥t✳ ❖♥❧② t✇♦ s✉❜❥❡❝ts ❤❛s ❜❡❡♥ ❝❤♦s❡♥ ❞✉❡ t♦ ❛ t❡❝❤♥✐❝❛❧ ❞✐✣❝✉❧t② ♦❢ ❡①♣❡r✐♠❡♥t✳ ❚❤❡ ❡❧❡❝tr✐❝❛❧ ❛❝t✐✈✐t② ♦❢ ♠✉s❝❧❡s ❤❛s ❜❡❡♥ ❛♥❛❧②s❡❞ ✇✐t❤ s✉r❢❛❝❡ ❡❧❡❝tr♦♠②♦❣r❛♣❤②✳ ❚❤❡r❡ ❤❛s ❜❡❡♥ ♠❡❛s✉r❡❞ ❢♦❧❧♦✇✐♥❣ ♠✉s❝❧❡s✿ ♠✳ ❞❡❧t♦✐❞❡✉s ♣❛rs ❛♥t❡r✐♦r✱ ♠✳ ❞❡❧t♦✐❞❡✉s ♣❛rs ♠❡❞✐❛❧✐s✱ ♠✳ ♣❡❝t♦r❛❧✐s ♠❛❥♦r ♣❛rs ❝❧❛✈✐❝✉❧❛r✐s ❛ ♠✳ tr✐❝❡♣s ❜r❛❝❤✐✐ ❝❛♣✉t ❧♦♥❣✉♠✱ ♠✳ ♣❡❝t♦r❛❧✐s ♠❛❥♦r ♣❛rs st❡r♥♦❝♦st❛❧✐s✱ ♠✳ ❜✐❝❡♣s ❜r❛❝❤✐✐✱ ♠✳ ❞❡❧t♦✐❞❡✉s ♣❛rs ♣♦st❡r✐♦r✱ ♠✳ ✐♥❢r❛s♣✐✲ ♥❛t✉s ❛ ♠✳ tr✐❝❡♣s ❜r❛❝❤✐✐ ❝❛♣✉t ❧❛t❡r❛❧❡✳ ❚❤❡ ❡❧❡❝tr✐❝❛❧ ❛❝t✐✈✐t② ♦❢...
|
|
|
Human locomotion after total hip replacement
Horáková, Alena ; Vilímek, Miloslav (advisor) ; Horák, Zdeněk (referee)
Title: Human locomotion after total hip replacement Objectives: The aim of this thesis is to perform a gait analysis of patients after total hip replacement and to find out, how chosen temporo-spatial, kinetic and kinematic parameters change during the first half a year after the surgery. The deviations found in gait stereotypes of individual patients are further compared with results of international studies. Methods: The thesis is theoretical-empirical, with small number of patients. 3D kinematic gait analysis was performed by Qualisys system and ground reaction forces by two Kistler force plates. The following parameters are being monitored: length of step, stance phase duration, cadence, walking speed, lateral shift of the pelvis and trunk in standing phase, contralateral pelvic drop in standing phase of the leg, maximum range of motion of the hip joint in sagital plain, maximum of vertical and medio-lateral component of the ground reaction forces in the standing phase. Results: The highest side deviations between legs were found in 3 months after the surgery and remained until 6,5 months after the surgery. In this time period a lower value of the length of step, stance phase duration, maximum range of motion of the hip joint in sagital plain and also a higher lateral shift of the pelvis was...
|
|
| |
|
|
Polyethylene wear particles around joint replacements - their properties, distribution and possible mechanism of their adverse biological effects
Zolotarevová, Eva ; Gallo, Jiří (advisor) ; Rauch, Pavel (referee) ; Horák, Zdeněk (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF SCIENCE DEPARTMENT OF BIOCHEMISTRY PRAGUE 2010 Supervisor: Doc. MUDr. Jiří Gallo, PhD. Supervisor-consultant: Prof. RNDr. Gustav Entlicher, CSc. Eva Zolotarevová Summary of PhD Thesis POLYETHYLENE WEAR PARTICLES AROUND TOTAL JOINT REPLACEMENTS - THEIR PROPERTIES, DISTRIBUTION AND POSSIBLE MECHANISM OF THEIR ADVERSE BIOLOGICAL EFFECTS PRAGUE 2010 The research project was supported by the Grant project of National research program II. (no. 2B06096) of the Czech Ministry of Education, Youth and Sports named "Observation and minimization of UHMWPE wear in joint replacements". Front-page picture: Polyethylene wear particle isolated from granuloma tissue surrounding total hip replacement; Electron microscope microphotograph; particle size app. 90 x 80 µm; retouched Eva Zolotarevová Introduction Introduction For many people all over the world a replacement with an implant of irreversibly damaged joint is often the only way how to come back to normal life without pain and mobility limitation. Nowadays, greater and greater requirements are asked of quality of all replacement components, especially in terms of quality of used materials. Biomechanical properties of hip and knee replacements have been already solved. The most often used materials for manufacturing joint...
|
|
|
Treatment of humeral diaphyseal fractures using Hackethals retrograde elastic nailing - a clinical and experimental verification of this method in contemporary traumatology
Obruba, Petr ; Džupa, Valér (advisor) ; Horák, Zdeněk (referee) ; Paša, Libor (referee)
Hackethal's bundle nailing of diaphyseal humeral fractures was historically reliable and cheap method, used for stabilization of simple humeral shaft fractures. After arrival of solid nails, this technique was successively abandoned, initially in Germany, followed by countries of Central Europe. Several cliniques are at present still using this technique successfully. Goal of this work was to establish, whether the declared stability of this technique is comparable to those of more evolved methods, whether this technique does not cause higher amount of complications, and to describe how the stability of nails bundle depends on number and diameter of used implants. The cost efficiency of different modern osteosynthetic methods used for stabilization of humeral shaft fractures was also analyzed. For verification of determined hypotheses, two clinical and one experimental studies were developed. First clinical study was focused on success rate of osteosynthesis and it's complications. In studied population of 50 patients, 4 of them (8%) developed a non-union, which was in all cases caused by wrong indication or technical error during implantation. Superficial infection was observed once, no deep infection had developed. Nine patients (18%) have healed in rotational or axial malalingement that had no...
|
|
|
Development of the coefficient of friction and lubrication film in a total knee replacement during a gait cycle
Odehnal, Lukáš ; Horák, Zdeněk (referee) ; Ranuša, Matúš (advisor)
This master´s thesis deals with the experimental analysis of the coefficient of friction and lubrication film in total knee replacement. The experiments are performed on a knee joint simulator, with an implemented module for measuring friction. To observe film formation, fluorescent microscopy is used. The experiments are mainly focused on a detailed description of the influence of parameters occurring during the gait cycle. This approach should significantly help in describing the tribological processes that occur in the total knee replacement. The results confirm previous investigations in terms of axial load, where the coefficient of friction decreases with the increasing load. In the case of lubrication film, no significant changes are observed. On the contrary, while investigating the influence of SRR, noticeable changes in film formation are observed while the coefficient of friction being unaffected. While describing the whole gait cycle, precise results are obtained only in the first half of the cycle as the second half is accompanied by the occurrence of large deviations from a rapid decrease of load. This work provides a better understanding of the field of lubrication film in total knee replacements. Moreover, thanks to the simultaneous measurement of the coefficient of friction and the observation of the contact area, it is possible to draw better conclusions than if the experiments had been carried out separately.
|
guest ::
