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Energy consumption of manual wheat grinding
Mařík, Vojtěch ; Hora, Martin (advisor) ; Sládek, Vladimír (referee)
In this thesis, the energy consumption during manual wheat grinding was investigated using two historically widespread and important technologies for grain grinding, namely the saddle quern and the rotary quern. This energy consumption was also compared to some anthropometric parameters of the grinding human. The method of indirect calorimetry using Cosmed K5 was used to measure energy expenditure. Bioimpedance scale InBody270 and basic anthropometric tools such as anthropometer and pelvimeter were used to determine selected body parameters.. The energy expenditure of grinding by the rotary quern was also measured by different movement patterns, namely unimanual clockwise and counter-clockwise rotation and bimanual counter-clockwise rotation. Energy expenditure was sampled on 30 women. It was found that although grinding on a saddle quern is an energetically less demanding activity compared to grinding on a rotary quern, significantly more energy is required to grind the same amount of cereal grains (297 kcal/kg grain vs. 109 kcal/kg grain). Clockwise milling was found to be the most energy-efficient variant of milling, while counter-clockwise milling was more energy demanding (clockwise milling 5.48 1.13 kcal/min vs. counter-clockwise milling 6.21 0.87 kcal/min). Anthropometric parameters...
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Influence of high level of stress on the adaptative mechanisms of the bones
Suková, Jaroslava ; Sládek, Vladimír (advisor) ; Struška, Michal (referee)
The main purpose of this paper is to describe the mechanism of the effect of high load on bone tissue and its ability to adapt to the given load. In the first part of this paper I am going to focus on the description of the mechanism of the load effect on bone tissue according to the mechanostat theory of Harold Frost and Jullius Wolff. In the second part I am going to describe how high load affects the bone tissue and how the adaptation mechanisms of the bone will react to the load. In this part I am also going to focus on pathological high load and the occurrence of cracks and fractures on bones due to this load being higher than the bone can sustain. In the last part of the paper I am going to focus on the bone repair mechanisms needed when fractures and cracks disrupt the integrity of the bone. Keywords Adaptability of the bone, physiological mechanisms of the bone, pathological overload, Frost's mechanostat, reparational mechanisms of the bone, bone damage
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The effect of the growth and development of the endosteal surface on the estimation of cross-sectional properties
Königová, Viktória ; Sládek, Vladimír (advisor) ; Friedl, Lukáš (referee)
Past studies concerning deriving periosteal and endosteal contours from micro-CT scans of non-adult long bones found the greatest error to stem from the automatic processing of the endosteal contours. Furthermore, with increasing age, a decrease in the estimation error of the cross-sectional properties was observed. This study aims to identify the specific source of the estimation error and to optimize the use of the automatic method of deriving endosteal contours. Four parameters (circularity, solidity, roundness, and aspect ratio) were used to quantify the shape properties of the endosteal contour. These parameters were tested on 91 individuals from birth to early adulthood. As for the ontogenic changes in the endosteal contour, a continuous decrease in the jaggedness of the endosteal contour had been observed, mainly based on the changes in the circularity. Circularity was chosen as the parameter upon which the criteria of use of the automatic method of deriving the endosteal contour was based. The criterium is based on the prediction of whether the customary threshold of 5 % percent prediction error would be surpassed while using the automatic method at a certain level of circularity. Applying the criteria of the minimum threshold of circularity (0,83 for MA, 0,71 for CA, and 0,7 for ZP) will...
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Evolutionary aspects of bipedalism in hominins
Pinterová, Nikola ; Sládek, Vladimír (advisor) ; Brůžek, Jaroslav (referee)
The work deals with the human bipedality, the previous locomotor behavior and possible reasons for its occurrence. For help finding Ardipithecus ramidus, who is dating close to the split of chimpanzees and humans, is studied prebipedal pattern of locomotor behavior. Emphasis is also placed on the way the movement of A. ramidus itself. On the basis of literary sources are in this thesis for an overview summarized the locomotor patterns of representatives Catarrhini and listed important adaptations to bipedality of the human skeleton. The adaptations then are the criterion for the evaluation of bipedalism in fossil bones of A. ramidus. Furthermore, we deal with evolutionary hypotheses about the origin of bipedalism. Key words Bipedalism, locomotion, human, chimpanzee, Ardipithecus ramidus ramidus, hominins, evolution
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Kinesiological aspects of lower limb bilateral asymmetry
Vondrášek, David ; Hora, Martin (advisor) ; Sládek, Vladimír (referee)
Lower limbs are under the influence of relatively symmetrical loading of gait, and even so there has been evidence of bilateral asymmetry of lower limb bones in skeletal remains. The goal of this study was to search literature for possible causes of bilateral asymmetry found in dimensions of lower limb bones. This bachelor's thesis views bilateral asymmetry of lower limbs of living human from a perspective of bilateral activities, such as walking, squats and jumps and from a perspective of unilateral activities, for example kicking in football and in Taekwondo. 59 scientific articles were used in total to write this bachelor's thesis. Results of scientific articles show, that one possible cause of bilateral asymmetry of lower limb bones is preference of the lower limbs for unilateral activities. According to kinesiological articles, the unilateral kicking activity creates great mechanical loading in hip, knee and ankle joints of the kicking lower limb.
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The influence of physiologically controlled motor activity on biomechanical cross-section properties of long bones.
Jindrová, Alena ; Sládek, Vladimír (advisor) ; Špoutil, František (referee)
The mechanical loading affects the long bone cross-section geometry (CSG). The aim of this thesis was to examine experimentally the relationship between the locomotory parameters and cross-sectional properties of long bones, and to test some partial knowledge of the bone mechanical adaptation. Two groups of B6CBA mice were examined: (a) Lurcher type (model of olivocerebellar degeneration; n = 10) and (b) control (normal mice; n = 10). We analyzed the motor characteristics and the bone cross-sectional geometric properties. The motor tests included the test of spontaneous motor activity (Open field), strength properties (horizontal bar) and motor coordination (rotarod). Cross-sections were taken in 50 % of the left tibia biomechanical length and further processed for fluorescence confocal microscopy. We analyzed the biomechanical properties of cortical bone cross-sections (software ImageJ). There were nonsignificant differences in CSG parameters (TA, CA, Imax, Imin, J, Imax/Imin) between Lurcher and control mice. The results did not support our assumption about the effect of motor disorder on CSG properties. We did not demonstrate the effect of local factors on the bone biomechanical adaptation. The results of this thesis may be useful to find new testing possibilities of cortical bone in...
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Development of human postcranial skeleton depending on terrain
Turková, Eliška ; Sládek, Vladimír (advisor) ; Hora, Martin (referee)
A human bone is a dynamic structure that changes tissue arrangement according to inner and outer stimuli. The outer stimuli include among others the mechanical, environmental, and climatic ones. The impact of mechanical stimuli on the bones shows already with natural activities such as walking and running through change in the shape of a transverse bone cross section. The changes in the bone cross section can be observed on bone findings of ancient populations. The cross section shape of the long bones of lower extremities changes from the Palaeolithic to Neolithic population in such a way that the circulation of transverse cross-section increases. The explanation of this trend lies in the change of subsistence strategies from the Palaeolithic to the Neolithic era. The subsistence economy of the Palaeolithic population demanded more movement in comparison to the Neolithic population that lived a more sedentary lifestyle. This trend might be challenged by few bone findings of the Neolithic population from the mountain regions (e.g. Liguria, Italy) whose transverse bone cross section are more of a elliptic shape. Those excavations are mostly situated in the mountain regions with a demanding terrain. The outcomes presented in this study suggest that terrain is one of the factors that affect the...
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Femoral and tibial cortical tissue distribution: the error ranges of cross-sectional parameters
Schuplerová, Eliška ; Sládek, Vladimír (advisor) ; Velemínská, Jana (referee)
In biomechanical analyses, the position of long bone cross-section under study is defined relatively to biomechanical length (BML) of the bone. In damaged bones where BML can not be measured, the position of the cross-section has to be estimated. Sládek et al. (2010) studied the effect of inaccurately located femoral and tibial midshafts on the cross-sectional parameters in a pooled-sex sample from a single period. In the present study we aim to test whether the effect of inaccurately located femoral and tibial midshafts on the cross-sectional parameters is sample-specific and/or sex-specific. We used femora of 29 females and 25 males and tibiae of 24 females and 36 males from two different periods (Late Eneolithic and Early Bronze Age; early modern period). 29 cross-section CT scans per bone obtained at each 1% interval from 40% to 60% of BML and at each 5% interval from 20-40% and 60-80% of BML were available to us. We digitized the cross-section scans and computed the error ranges of the cross-sectional parameters. We compared the mean percentage difference (MD%) and mean accuracy range (MAR) between samples and sexes. Our results are in concordance with the results of Sladek et al. (2010): the cross-sectional parameters most sensitive to positioning error are tibial second moments of area (MAR...
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Sexual Dimorphism in the Skeleton of La Tène Population in Bohemia and Moravia
Jandová, Petra ; Brůžek, Jaroslav (advisor) ; Sládek, Vladimír (referee)
The purpose of the thesis is the evaluation of sexual dimorphism of La Tène population of Bohemia and Moravia, compare it subsequently with other European populations from the same period and comment on potential homogeneity or heterogeneity of the population. The level of sexual dimorphism was determined and compared by stature estimation of the studied population. For approximation to the sex represented by the largest number of individuals we chose the principle of primary and secondary sex diagnosis. Based on this principle, we created a discriminant functions for sex determination using the long bones dimension (humerus, femur and tibia). From the results we learn that statistically significant differences between the sexes of La Tène population of Bohemia and Moravia in all measured dimensions of long bones and body height itself were detected. The average stature of a male is 168 cm and 160,8 cm of a female. Comparison of our data with the study from Italy indicates that there is significant difference in body height, but not in the degree of sexual dimorphism of stature and long bones. Based on our data we couldn't make sufficient comment on potential homogeneity or heterogeneity. The obstacle in the response of this question is the very nature of La Tène skeletal material, which is in very...
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Throwing ability in human evolution
Struška, Michal ; Sládek, Vladimír (advisor) ; Hora, Martin (referee)
The aim of this thesis is to describe the origin of bone markers that characterize individuals who throw habitually and the usability of these markers in research of past populations. The thesis also summarizes knowledge of the origin and development of projectile weapons in Pleistocene. The effectiveness (accuracy and speed) of throw is probably related to differences in morphology of pectoral girdle, torso and hand. Therefore, a part of the text summarizes the morphology of pectoral girdle, torso and hand in the species H. erectus, which was probably the first group of hominins able to throw with effectiveness close to the one of anatomically modern humans. The development of projectile technology, which came after the adoption of effective throwing ability, is usually inferred from archaeological findings of spears and arrows. Various interpretations of archaeologically found weapons bring different conclusions regarding the usage of these weapons. The usage may be inferred from bone characteristics originating as consequences of moves that individual executes when manipulating weapons.
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