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The patterning and determinants of craniofacial robusticity in extant Homo sapiensMiller, Steven Frederick 01 December 2010 (has links)
Skeletal superstructure characteristics such as thick cranial vaults and well-developed supraorbital, infraorbital, zygomatic, temporal, and nuchal regions in hominins are collectively referred to as aspects of craniofacial robusticity. A better understanding of craniofacial robusticity is important because these features are regularly employed as individual traits in circumscribing fossil hominins as a means to separate other taxonomic groups from modern Homo sapiens even though the developmental and functional underpinnings of such traits are incompletely understood. The work of some researchers suggests that these features may be tied to a broader "robusticity complex", in which the expression of all the classically "robust" characteristics of the hominin cranium are intercorrelated and intrinsically linked. If true, then previous studies that have focused on characteristics of craniofacial robusticity as individual characters could be flawed.
This study tests for the presence of an intercorrelated craniofacial robusticity complex in a geographically diverse sample of recent Homo sapiens using a morphological integration framework. Within this framework, significant levels of correlation between features of craniofacial robusticity are demonstrative of integration and thus a "robusticity complex", while non-significant levels of correlation provide evidence for modularity and therefore an independent expression of these traits. Craniofacial robusticity is examined among four anatomical areas of the human cranium including the frontal, zygomaxillary, temporal, and occipital regions. The expression of robusticity among these anatomical regions is quantified using three-dimensional coordinate landmark data in addition to classical discrete measures and is analyzed via two-block partial least squares regression analysis.
The results show that levels of interaction between these major anatomical units are characterized by a range of correlation values with most obtaining statistical significance. These results frequently provide evidence for integration between subunits demonstrating at least partial evidence for a "robusticity complex" in the craniofacial skeleton of extant humans.
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The femoral shaft waist, an alternative robusticity measure: its distribution, relation to midshaft, and applicability to behavioral reconstructionsJanuary 2013 (has links)
Midshaft is the most commonly used site for behavioral and robusticity inferences in cross-sectional studies of the femur. This work tries to revive an alternative location because the midshaft, as much as it is easy to locate, does not necessarily reflect the same adaptive remodeling in every individual. Femoral waist which is defined as the shaft’s mechanically weakest point is reintroduced as an alternative. The aim of this work is to describe waist’s general patterns of distribution along the shaft, to test which morphological characteristics influence its position, to compare its inferential potential with the midshaft, and to evaluate applicability of the concept under the mechanical predictions about stress and strain distribution along the femur. A total of 251 individuals representing four temporal samples spanning the Eneolithics to 19th century were analyzed using CT-derived cross-sectional properties. The results showed that the femoral waist tends to center around the midshaft but with a rather large amount of variation and that the samples do not seem to differ in this respect. General levels of mechanical loading and robusticity may influence its distribution as evidenced from the Early Middle Ages males who were the most robust group (in body size adjusted parameters) and had their waists positioned more proximally. Variables that influence waist’s location are primarily related to strain distribution but not its magnitude. Thus, neck-shaft angle, anteversion angle, femoral inclination, crural index, and femoral curvature proved to be significant predictors (their importance varies between sexes), while body size measures were insignificant. Behavioral and robusticity inferences made from the femoral waist and midshaft are rather incompatible. In closely related populations, results from the two locations would probably lead to different interpretations while in rather distant units (species or genera), this would not be as problematic. Whenever possible, true cross-sectional properties should be used to locate the femoral waist. External methods using subperiosteal contour are more acceptable than methods estimating cross-sectional properties only from external dimensions. Lastly, the femoral waist position can potentially be used for taxonomic purposes in earlier hominins as well as for the reconstruction of other femoral characteristics (e.g., femoral length). / acase@tulane.edu
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Scaling Patterns and Ecological Correlates of Postcranial Skeletal Robusticity in Canis and Ursus: Implications for Human EvolutionDoyle, Sara Kathleen January 2009 (has links)
<p>There has been a trend toward decreasing skeletal robusticity in the genus Homo throughout the Pleistocene, culminating in the gracile postcrania of living modern humans. This change is typically attributed to changing tool technologies and subsistence patterns among human groups. However, other mammalian groups also experience a similar change in their postcranial strength over the same time period. It is proposed in this dissertation that ecological variables are correlated with measures of postcranial strength and may be a better explanation for Holocene skeletal gracilization in humans, as well as in other mammalian genera. This hypothesis is investigated through a close examination of the scaling patterns in two extant genera, Canis and Ursus, and a comparison of scaling patterns and relative strength of different species of Canis, including a fossil species that provides information about temporal change. Measurements of limb length, joint surface area, bone diameter, and strength measurements derived from radiographic images of long bone midshafts of North American specimens of Canis, (including the fossil Canis dirus) and Ursus were collected. Scaling patterns of the cross-sectional variables on limb length and joint surfaces were analyzed for the interspecific and intraspecific samples. </p><p>The first hypothesis tested was that Canis scales with geometric similarity of cross-sectional variables on bone length and body mass, and the Ursus scales with elastic similarity. Larger Canis have relatively stronger postcrania than smaller Canis. The primary way in which this strength is achieved in larger individuals is through a relatively shortening of the bone length. The second hypothesis tested was that postcranial strength is correlated with ecological variables. To investigate this hypothesis, scaling patterns of different species of Canis were compared, including the fossil dire wolf. The results show that the dire wolf is relatively stronger than its living congenerics. There is also a strong relationship between the ratio of prey body mass to predator body mass and relative strength for these species. Carnivores that are hunting animals much larger than themselves must have postcranial skeletons that are strong enough to withstand the loading of the skeleton that occurs during hunting, taking down, and processing large herbivores.</p> / Dissertation
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Os sepultados de Jabuticabeira II, SC - insights e inferências sobre padrões fenotípicos, análise de modo de vida e organização social através de marcadores de estresse músculo-esqueletal / The buried people of Jabuticabeira II, SC - insights and inferences about phenotypic patterns, way of life analysis and social organization by musculo-skeletal markersAbbas, Adam Reiad 17 April 2013 (has links)
Os marcadores de estresse músculo-esqueletal (MSMs), assim denominados, surgem pela primeira vez em 1995 no trabalho pioneiro de Hawkey e Merbs. De lá pra cá, diversos estudos se prestaram a aprimorar o método desenvolvido pelos pesquisadores e, ainda, associar de maneira mais concreta os graus de desenvolvimento de enteses a atividades desenvolvidas ao longo da vida de um indivíduo. Sob tais circunstâncias, buscamos neste trabalho a verificação da implementação de uma metodologia de análise revisada, testada e aprimorada dos marcadores de estresse músculo-esqueletal e a possibilidade de correlação entre os graus de desenvolvimento das enteses estudadas com as possíveis atividades desenvolvidas pelos indivíduos analisados, provenientes do sambaqui costeiro catarinense Jabuticabeira II (JAB-II). A escolha pela análise dos remanescentes ósseos deste sítio decorreu da vasta informação disponível em relação aos mesmos e ao sítio em si, provindos de outros trabalhos desenvolvidos previamente. Assim, estudos de paleopatologia e arqueologia possibilitaram melhores interpretações dos resultados obtidos pelas análises de MSMs. Neste trabalho procuramos adaptar a metodologia desenvolvida por Mariotti (2004,2007) para amostras antigas (mais de 2000 anos atrás) e de baixa conservação. Além disso, realizamos inferências sobre as atividades desenvolvidas pelos indivíduos sepultados em JAB-II, a divisão de tais atividades baseada em sexo e faixa etária, a avaliação dos graus de entesopatias (lesões na região entesal que vão além do desenvolvimento saudável de uma entese) e sua frequência na população estudada, a correlação do grau de desenvolvimento de entese com outro marcador muito comum em estudos de paleopatologia, a osteoartrose e, por fim, estabelecer, ainda que de forma tímida, o perfil físico típico do indivíduo de JAB-II, baseado na avaliação de todas as enteses disponíveis para estudo (1067 enteses disponíveis entre homens e mulheres adultos). A metodologia de estudo se mostrou eficaz, feitas às devidas adaptações metodológicas, com aprovação da proponente do método original. O erro intra-observacional, valor de erro de concordância calculado entre duas análises para o mesmo conjunto de enteses, com intervalo de tempo longo (3 meses), pelo mesmo avaliador, ficou dentro dos padrões aceitáveis pela comunidade científica (20%). Verificou-se, ainda, grande prevalência de alta robustez para a totalidade de enteses avaliadas. Quando analisados os complexos funcionais (conjunto de músculos e articulações envolvidas na realização de um movimento) verificou-se também alta prevalência de robustez elevada, com destaque para os complexos dos membros inferiores, antes tidos como pouco requisitados devido à baixa prevalência de osteoartrose nos mesmos. A avaliação de complexos funcionais é mais efetiva para a correlação dos graus de robustez com atividades realizadas no dia-a-dia já que várias destas envolvem a ação de mais de um músculo para a sua realização. Homens e mulheres apresentaram diferenças estatisticamente significantes com relação ao desenvolvimento de suas enteses, sendo os homens mais robustos que as mulheres. O mesmo verificou-se em relação às faixas etárias, sendo os indivíduos mais velhos mais robustos. Com relação às entesopatias, não verificamos diferenças na prevalência de entesofitóses tanto quanto a sexo quanto a faixas etárias. Com relação às lesões líticas (outra entesopatia analisada) verificaram-se diferenças estatisticamente significantes entre os sexos, com maior prevalência de tal marcador na parcela masculina. Já em relação às faixas etárias, não se verificaram diferenças estatisticamente relevantes. Por fim, por ser um traço esqueletal associado à atividade física, procuramos relacionar as osteoartroses previamente estudadas na amostra com os graus de desenvolvimento de entese avaliados neste trabalho. Não foram encontradas correlações de qualquer natureza entre os dois marcadores mas, devemos chamar atenção ao elevado número de enteses nas quais se verificaram alta robustez com baixo nível de osteoartrose. Tal observação poderia indicar possíveis relações de proteção da articulação devido à atividade física intensa, inferida indiretamente pelo grau de desenvolvimento da entese. Podemos assim supor que o indivíduo sepultado em JAB-II, independentemente de sexo e idade, seria um indivíduo robusto, de musculatura avantajada, compatível com o grau de atividade física desempenhada possivelmente em seu dia a dia e com seus possíveis hábitos alimentares / The so called Musculo-Skeletal Stress markers (MSM) enriched the wealth of possibilities to infer past life styles since 1995 with the Hawkey and Merbs work on Inuit populations. Since then, many studies tried to improve the method developed by these two researchers and associate the development of the entheses to certain physical activities . Under these circumstances, in this work we tested, modified and adapted this method to analyze MSM, and the possibility to correlate the degrees of development of the entheses with the possible activities performed by the individuals of individuals excavated from the costal Shellmound of Santa Catarina (BR) called Jabuticabeira II (JAB-II). We choose to analyze the osteological collection from this site due to extensive previous information available on its burials and on the site itself, because palaeopathology and archaeology studies render better interpretations of the results obtained by the MSM analyses. In this work, we adapt the methodology developed by Mariotti (2004,2007) to ancient samples (more than 2000 years old), with low state of preservation. We also used MSM to infer about the daily activities performed by the people buried at JAB-II, the division of labour based on sex and age, the evaluation of the severity of enthesopaties (pathological lesions on the enthesis) and it´s frequency in the population studied, the correlation between the enthesis´ severity and osteoarthrosis, and, finally, establish, even if in a very cautious way, the typical body type profile of the JAB-II population, based on the evaluation of the 1067 entheses available for analysis. The method adopted was effective as long as adapted to our sample, with the acceptance of the method developer (Mariotti). The intra-observer error, concordance error value between two analyses, three months apart, of the same set of enthesis, performed by the same observer is acceptable by the scientific community (20%). Were observed a high prevalence of increased robusticiy for all entheses evaluated individually and grouped into functional complexes (set of muscles and joints involved in the performance of a given movement). However, contrary to earlier interpretations based on osteoarthritis, the lower limbs must have been more requested than the upper ones. The evaluation of functional complexes is more effective for the correlation between robusticity and daily activities, given the requirement of more than one muscleusually used to perform one single movement. We found statistically significant differences between the male and female samples for the development of the entheses, with the male portion presenting more entheses with high robusticity than females. The same was observed within age classes, where older adults present higher enthesis robusticiy. We did not find significant statistical differences in the prevalence of enthesophytic formations between sexes and age classes. For the osteolytic formations we found significant statistical differences between the sexes, with higher prevalence among males, whereas no differences were observed between the age classes. Finally, for being an skeletal marker associated to physical activity, we tried to correlate osteoarthrosis (previously studied in this sample) with the developmental degrees of the entheses. No correlations of any nature were found between the two markers. Nevertheless,the elevated number of entheses with high robusticity and low levels of osteoarthrosis suggest that frequent and/or intense physical activity may protect the joints from osteoarthritis
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Comparative and Experimental Investigations of Cranial Robusticity in Mid-Pleistocene HomininsJanuary 2012 (has links)
abstract: Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but potential mechanisms underlying this seemingly unique trait have not been rigorously investigated. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. Identifying factors that affect CVT would be exceedingly valuable in teasing apart potential contributors to thick vaults in the Pleistocene. Four hypotheses were tested using CT scans of skulls of more than 1100 human and non-human primates. Data on total frontal, parietal, and occipital bone thickness and bone composition were collected to test the hypotheses: H1. CVT is an allometric consequence of brain or body size. H2. Thick cranial vaults are a response to long, low cranial vault shape. H3. High masticatory stress causes localized thickening of cranial vaults. H4. Activity-mediated systemic hormone levels affect CVT. Traditional comparative methods were used to identify features that covary with CVT across primates to establish behavior patterns that might correlate with thick cranial vaults. Secondly, novel experimental manipulation of a model organism, Mus musculus, was used to evaluate the relative plasticity of CVT. Finally, measures of CVT in fossil hominins were described and discussed in light of the extant comparative and experimental results. This dissertation reveals previously unknown variation among extant primates and humans and illustrates that Homo erectus is not entirely unique among primates in its CVT. The research suggests that it is very difficult to make a mouse grow a thick head, although it can be genetically programmed to have one. The project also identifies a possible hominin synapomorphy: high diploë ratios compared to non-human primates. It also found that extant humans differ from non-human primates in overall pattern of which cranial vault bones are thickest. What this project was unable to do was definitively provide an explanation for why and how Homo erectus grew thick skulls. Caution is required when using CVT as a diagnostic trait for Homo erectus, as the results presented here underscore the complexity inherent in its evolution and development. / Dissertation/Thesis / Ph.D. Anthropology 2012
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Srovnání změn somatotypu mezi hráči ledního hokeje, reprezentace 1976 a reprezentačním výběrem U19 v sezóně 2017-2018 / Comparison of somatotype profiles in ice hockey players of national team 1976 and national team U19 season 2017-2018Rybársky, Matej January 2018 (has links)
Title: Comparison of somatotype profiles in ice hockey players of national team 1976 and national team U19 season 2017-2018. Objectives: The main aim of this thesis is to compare the level of somatotype profile changes between national team of Czechoslovakia from 1976 and Czech republic national team U19 playing in season 2017-2018. Methods: For purpose of study the observation research method was used. Research samples were made of 41 ice hockey players, specifically players of Czechoslovak national team from 1976 (n=24) and players of Czech national team U19 in season 2017-2018 (n=17). The somatotype was determined using Heath and Carter method (1990). To determine the degree of differences between the given parameters, the effect size of Cohen d was used, d ≥ 0,5 a d ≥ 0,8 depending on the hypothesis formulated. Results: Results showed, that the endomorphy of U19 players was significantly greater compared to ČSSR 1976 players (Cohen d = 0,65). The biggest difference was revealed at supraspinale skinfold (Cohen d = 1,06). On the other hand, we found significantly lower mesomporhy in U19 players (Cohen d = 1,63). The cause of this lower mesomoprhy was mainly due to significantly lower bone robusticity of the humerus (Cohen d = 0,81) and femur (Cohen d = 1,19). Keywords: somatotype, ice hockey,...
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Os sepultados de Jabuticabeira II, SC - insights e inferências sobre padrões fenotípicos, análise de modo de vida e organização social através de marcadores de estresse músculo-esqueletal / The buried people of Jabuticabeira II, SC - insights and inferences about phenotypic patterns, way of life analysis and social organization by musculo-skeletal markersAdam Reiad Abbas 17 April 2013 (has links)
Os marcadores de estresse músculo-esqueletal (MSMs), assim denominados, surgem pela primeira vez em 1995 no trabalho pioneiro de Hawkey e Merbs. De lá pra cá, diversos estudos se prestaram a aprimorar o método desenvolvido pelos pesquisadores e, ainda, associar de maneira mais concreta os graus de desenvolvimento de enteses a atividades desenvolvidas ao longo da vida de um indivíduo. Sob tais circunstâncias, buscamos neste trabalho a verificação da implementação de uma metodologia de análise revisada, testada e aprimorada dos marcadores de estresse músculo-esqueletal e a possibilidade de correlação entre os graus de desenvolvimento das enteses estudadas com as possíveis atividades desenvolvidas pelos indivíduos analisados, provenientes do sambaqui costeiro catarinense Jabuticabeira II (JAB-II). A escolha pela análise dos remanescentes ósseos deste sítio decorreu da vasta informação disponível em relação aos mesmos e ao sítio em si, provindos de outros trabalhos desenvolvidos previamente. Assim, estudos de paleopatologia e arqueologia possibilitaram melhores interpretações dos resultados obtidos pelas análises de MSMs. Neste trabalho procuramos adaptar a metodologia desenvolvida por Mariotti (2004,2007) para amostras antigas (mais de 2000 anos atrás) e de baixa conservação. Além disso, realizamos inferências sobre as atividades desenvolvidas pelos indivíduos sepultados em JAB-II, a divisão de tais atividades baseada em sexo e faixa etária, a avaliação dos graus de entesopatias (lesões na região entesal que vão além do desenvolvimento saudável de uma entese) e sua frequência na população estudada, a correlação do grau de desenvolvimento de entese com outro marcador muito comum em estudos de paleopatologia, a osteoartrose e, por fim, estabelecer, ainda que de forma tímida, o perfil físico típico do indivíduo de JAB-II, baseado na avaliação de todas as enteses disponíveis para estudo (1067 enteses disponíveis entre homens e mulheres adultos). A metodologia de estudo se mostrou eficaz, feitas às devidas adaptações metodológicas, com aprovação da proponente do método original. O erro intra-observacional, valor de erro de concordância calculado entre duas análises para o mesmo conjunto de enteses, com intervalo de tempo longo (3 meses), pelo mesmo avaliador, ficou dentro dos padrões aceitáveis pela comunidade científica (20%). Verificou-se, ainda, grande prevalência de alta robustez para a totalidade de enteses avaliadas. Quando analisados os complexos funcionais (conjunto de músculos e articulações envolvidas na realização de um movimento) verificou-se também alta prevalência de robustez elevada, com destaque para os complexos dos membros inferiores, antes tidos como pouco requisitados devido à baixa prevalência de osteoartrose nos mesmos. A avaliação de complexos funcionais é mais efetiva para a correlação dos graus de robustez com atividades realizadas no dia-a-dia já que várias destas envolvem a ação de mais de um músculo para a sua realização. Homens e mulheres apresentaram diferenças estatisticamente significantes com relação ao desenvolvimento de suas enteses, sendo os homens mais robustos que as mulheres. O mesmo verificou-se em relação às faixas etárias, sendo os indivíduos mais velhos mais robustos. Com relação às entesopatias, não verificamos diferenças na prevalência de entesofitóses tanto quanto a sexo quanto a faixas etárias. Com relação às lesões líticas (outra entesopatia analisada) verificaram-se diferenças estatisticamente significantes entre os sexos, com maior prevalência de tal marcador na parcela masculina. Já em relação às faixas etárias, não se verificaram diferenças estatisticamente relevantes. Por fim, por ser um traço esqueletal associado à atividade física, procuramos relacionar as osteoartroses previamente estudadas na amostra com os graus de desenvolvimento de entese avaliados neste trabalho. Não foram encontradas correlações de qualquer natureza entre os dois marcadores mas, devemos chamar atenção ao elevado número de enteses nas quais se verificaram alta robustez com baixo nível de osteoartrose. Tal observação poderia indicar possíveis relações de proteção da articulação devido à atividade física intensa, inferida indiretamente pelo grau de desenvolvimento da entese. Podemos assim supor que o indivíduo sepultado em JAB-II, independentemente de sexo e idade, seria um indivíduo robusto, de musculatura avantajada, compatível com o grau de atividade física desempenhada possivelmente em seu dia a dia e com seus possíveis hábitos alimentares / The so called Musculo-Skeletal Stress markers (MSM) enriched the wealth of possibilities to infer past life styles since 1995 with the Hawkey and Merbs work on Inuit populations. Since then, many studies tried to improve the method developed by these two researchers and associate the development of the entheses to certain physical activities . Under these circumstances, in this work we tested, modified and adapted this method to analyze MSM, and the possibility to correlate the degrees of development of the entheses with the possible activities performed by the individuals of individuals excavated from the costal Shellmound of Santa Catarina (BR) called Jabuticabeira II (JAB-II). We choose to analyze the osteological collection from this site due to extensive previous information available on its burials and on the site itself, because palaeopathology and archaeology studies render better interpretations of the results obtained by the MSM analyses. In this work, we adapt the methodology developed by Mariotti (2004,2007) to ancient samples (more than 2000 years old), with low state of preservation. We also used MSM to infer about the daily activities performed by the people buried at JAB-II, the division of labour based on sex and age, the evaluation of the severity of enthesopaties (pathological lesions on the enthesis) and it´s frequency in the population studied, the correlation between the enthesis´ severity and osteoarthrosis, and, finally, establish, even if in a very cautious way, the typical body type profile of the JAB-II population, based on the evaluation of the 1067 entheses available for analysis. The method adopted was effective as long as adapted to our sample, with the acceptance of the method developer (Mariotti). The intra-observer error, concordance error value between two analyses, three months apart, of the same set of enthesis, performed by the same observer is acceptable by the scientific community (20%). Were observed a high prevalence of increased robusticiy for all entheses evaluated individually and grouped into functional complexes (set of muscles and joints involved in the performance of a given movement). However, contrary to earlier interpretations based on osteoarthritis, the lower limbs must have been more requested than the upper ones. The evaluation of functional complexes is more effective for the correlation between robusticity and daily activities, given the requirement of more than one muscleusually used to perform one single movement. We found statistically significant differences between the male and female samples for the development of the entheses, with the male portion presenting more entheses with high robusticity than females. The same was observed within age classes, where older adults present higher enthesis robusticiy. We did not find significant statistical differences in the prevalence of enthesophytic formations between sexes and age classes. For the osteolytic formations we found significant statistical differences between the sexes, with higher prevalence among males, whereas no differences were observed between the age classes. Finally, for being an skeletal marker associated to physical activity, we tried to correlate osteoarthrosis (previously studied in this sample) with the developmental degrees of the entheses. No correlations of any nature were found between the two markers. Nevertheless,the elevated number of entheses with high robusticity and low levels of osteoarthrosis suggest that frequent and/or intense physical activity may protect the joints from osteoarthritis
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Differentiation of Labor-Related Activity by Means of Musculoskeletal MarkersDoying, Annette 23 March 2010 (has links)
This study tests whether musculoskeletal markers are attributable to occupational categories. It is hypothesized that individuals over the age of 30 years with a lifetime occupation as a laborer will demonstrate a significantly different pattern of activity markers from individuals in the white collar classifications. A sample of n=69 from the Maxwell Museum's Documented Skeletal Collection are investigated.
Upper and lower extremities were scored for MSM type (robusticity, stress lesions, and ossification exostoses) and severity (grades 0 - 3) following Hawkey and Merbs (1995) visual reference system. To evaluate methodological approaches to MSM scoring, ossification exostoses and stress lesions were also scored using the Mariotti et al. (2004) proposed methods. Upper limb muscle insertion sites on the humerus, radius, and ulna and lower limb insertion sites on the femur, fibula, patella, calcaneus, and tibia were studied.
The Kruskal Wallis test was used to predict occupational class according to an individual's aggregate MSM z-score. The Mann-Whitney test was used for comparison of aggregate MSM z-scores between the two occupational categories and for comparison of aggregate MSM z-scores between males and females. The Spearman correlation was used for non-parametric correlation analysis of aggregate MSM z-scores and the occupational categories of white collar and labor. The data were analyzed using the statistical software program SPSS (version 17.0).
Results of this study show that musculoskeletal markers cannot statistically predict, nor can they be used to distinguish between, occupational categories of white collar and labor. Comparison of MSM shows no significant difference in the overall patterns of enthesopathies between individuals who report an occupation of white collar or those who report an occupation of laborer as defined by the U.S. Office of Personnel. Comparison of MSM in this population shows no significant difference between males and females, regardless of occupational category, a finding which runs counter to many earlier studies.
Using dichotomous data it is revealed that laborers develop MSM symmetrically, evidence of whole-body activity. Further, white collar MSM can be associated with sitting and elevating the arm. Laborer's MSM are associated with lifting, twisting, pushing, squatting, walking, running and standing.
Recommendations on methodology are provided.
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Direkcionální asymetrie aktivity svalů horní končetiny a zad při nátahu luku; implikace pro bioarcheologii / Directional asymmetry of upper limb and back muscle activity during bow draw; implications for bioarcheologyVéle, Dominik January 2020 (has links)
This theses explores muscle activity during bow draw. The goal of his study is to evaluate whether muscle activity corresponds with increase in mechanical robusticity of the left humerus found in mezolithic osteological material. Muscle activity is measured by the means of surface electromyography. We measure activity of arm and back muscles. Activity was measured on m. deltoideus, m. infraspinatus, m. biceps brachii, m. triceps brachii and m. latissimus dorsi. Muscle activity was measured on 20 male archers, during bow draw of three wooden long-bows. Results of this study support the idea that change in robusticity of the left humerus could be caused by frequent bow use in post-glacial Europe.
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Humeral torsion and activity-related change in the human upper limb and pectoral girdle : a biomechanical investigation and social implicationsRhodes, Jill Anne January 2004 (has links)
This project investigas humeral torsion and activity-related change in the human upper limb. Increased humeral torsion angles have been identified in the professional throwing athlete and may be associated with strenuous activity. The nature of humeral torsion as an osteogenic response to the strain environment is investigated to identify its role in the behavioural morphology of the upper limb. These physical manifestations of strenuous physical activity provide an insight into the make-up of medieval armies prior to the establishment of standing armies. Populations analysed include two blade-injured samples, Towton and a subsample of blade-injured men from the Priory of St. Andrew, Fishergate, York. The men from the Mary Rose, a Tudor warship are also investigated. Other samples analysed include the rural sites of Wharram Percy and Hickleton, the urban cemeteries from the Priory of St. Andrew, Fishergate,York and the leprosarium of Sts. James and Mary Magdalene, Chichester, the modern cadaver-based Terry collection and non-human primates, Gorilla sp., Pan sp., Pongo sp., and Macaca sp.. Measurement of the humeral torsion angle and external measurements and indices of architecture, articulations and robusticity are employed. Cross-sectional geometric properties are investigated using CT imaging of the paired humeri from a sub-sample of blade-injured individuals and a comparative sample of those who were not. Bilateral asymmetry is investigated to identify the role of plasticity within the humerus and to reveal aspects of limb dominance. The results are compared with non-human primate species to obtain insight into inter-species differences. Results indicate the humeral torsion is not ontogenetically constrained, but is highly variable between and within populations, individuals and even between sides. Biomechanical analyses indicate that in the Towton population, humeral torsion may serve as part of a two-stage adaptation, in which the architecture is modified to enable greater biomechanical efficiency in distributing strain, reducing the need of increased cortical thickness. Changes in humeral torsion related to strenuous activity have been identified, although in the blade-injured samples it is decreased torsion angles, w hile in the comparative sample it is increased torsion angles that significantly correlate with limb hypertrophy. Humeral torsion appears to be influenced by other measurementd of humeral architecture, specifically, the amount of anterior bowing and anterior curvature to the distal humeral shaft. This work demonstrates the need for individual rather than population-based analyses, as the heterogeneity within population samples obscures individual variation in activity patterns. This analysis provides baseline data for typical populations of the Middle Ages. From this, it is then possible to investigate the individual within this baseline, to identify those who stand out from their samples through habitual, strenuous activity patterns. Movement patterns identified related to warfare include those consistent with the use of the longbow in the Towton sample and the use of a sword in the Fishergate blade-injured sample. These men, and those of the Mary Rose, appear to have either been selected for combat based on size, or benefited from a more nutritious diet during growth.
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