Oldenburg, Universiẗat, Diss., 2004. / Dateien in unterschiedlichen Formaten.

Thesis (M Dent (Orthodontics)) -- University of Limpopo, 2011 / Introduction: Flexion of the cranial base plays a very crucial role in the study of the craniofacial complex, particularly with the development of skeletal jaw relationships. An understanding of growth of the cranial base has come to assume great importance in orthodontics, and successful treatment of skeletal jaw malrelationships depends largely on the growth and flexion of the patients' cranial base. The aim of this study was to determine the relationship between cranial base flexion and skeletal jaw relationships in a sample of Black South Africans. Materials and method: The sample comprised of 300 pre-treatment lateral cephalograms of Black South Africans which was equally divided into Class I, Class . II and Class III skeletal jaw relationships according to the cephalometric tracing and analysis, and each class of skeletal jaw relationship had an equal number of male and female subjects. A digital cephalometric analysis software program (Orthview<ID, Netherlands) was used to trace and analyse the selected lateral cephalograms. The sample was first analysed to determine if gender differences existed for the mean cranial base flexion value in all three classes of skeletal jaw relationships. , , Comparisons among Class I, II and III mean cranial base flexton values using an independent t-test were made. The averag~ cranial base 'flexion value of the Black South Africans in this study was also compared with the average cranial base flexion value of Black and Caucasian South Africans from the previous studies for significance using an independent t-test. Results: Age distribution showed no statistically significant differences in all the three classes of skeletal jaw relationship (p > 0.05). There were no statistically significant differences between the mean cranial base flexion values of the male and female subjects in all the three classes of skeletal jaw relationships (p > 0.05). The results of this study demonstrated a significantly larger mean cranial base flexion value in the Class II skeletal jaw relationship sample when it was compared with the mean cranial base flexion values of Class I and Class III skeletal jaw relationship samples respectively (p < 0.05). There was no statistically significant difference between Class I and Class III skeletal jaw relationship samples with regards to the cranial base flexion (p> 0.05). The results of this study also showed no statistically . significant difference between the average cranial base flexion values of Black South Africans of the present study as well as Black and Caucasian South Africans of the previous study (p > 0.05). Conclusion: It was concluded that, in this sample, a larger cranial base flexion value is a feature of Class II skeletal jaw relationship and a smaller cranial base flexion value is a feature of both Class I and Class 11\ skeletal jaw relationships. Keywords: cranial base flexion, skeletal classification, skeletal jaw malrelationship

Reproduction de : Thèse de docteur-ingénieur : Mécanique : Metz : 1971. / Titre provenant de l'écran-titre. Notes bibliogr.

Universiẗat, Staatsexamensarbeit, 2007--Köln.

Universiẗat, Diss., 2001--Jena.

Among several work-related injuries, low back disorders (LBDs) are the leading cause of lost workdays, and with annual treatment costs in excess of $10 billion in the US. Epidemiological evidence has indicated that prolonged and/or repetitive non-neutral postures, such as trunk flexion, are commonly associated with an increased risk of LBDs. Trunk flexion can result in viscoelastic deformations of soft tissues and subsequent mechanical and neuromuscular alterations of the trunk, and may thereby increase LBD risk. While viscoelastic behaviors of isolated spinal motion segments and muscles have been extensively investigated, in vivo viscoelastic responses of the trunk have not, particularly in response to flexion exposures. Further, most biomechanical efforts at understanding occupational LBDS have not considered the influence of flexion exposures on spine loads. Four studies were completed to characterize viscoelastic deformation of the trunk in response several flexion exposures and to develop and evaluate a computational model of the human trunk that accounts for time-dependent characteristics of soft tissues. Participants were exposed to prolonged flexion at different trunk angles and external moments, and repetitive trunk flexion with different external moments and flexion rates. Viscoelastic properties were quantified using laboratory experiments and viscoelastic models. A multi-segment model of the upper body was developed and evaluated, and then used to estimate muscle forces and spine loads during simulated lifting tasks before and after prolonged trunk flexion at a constant angle and constant external moment. Material properties from the earlier experiments were used to evaluate/calibrate the model. Experimental results indicated important effects of flexion angle, external moment, and flexion rate on trunk viscoelastic behaviors. Material properties from fitted Kelvin-solid models differed with flexion angle and external moment. Nonlinear viscoelastic behavior of the trunk tissues was evident, and predictive performance was enhanced using Kelvin-solid models with ≥2 iii retardation/relaxation time constants. Predictions using the multi-segment model suggested increases in spine loads following prolonged flexion exposures, primarily as a consequence of additional muscle activity. As a whole, these results help to characterize the effects of trunk flexion exposures on trunk biomechanics, contribute to more effective estimates of load distribution among passive and active components, enhance our understanding of LBD etiology, and may facilitate future controls/interventions. / Ph. D.

Diss.--Germanistik--Freie Universität Berlin, 1992. / Bibliogr. p. 424-439. Index.

Master of Science / Department of Clinical Sciences / Warren L. Beard / The flexion test is routinely used in lameness and pre-purchase examinations. There is no accepted standard for duration of flexion or evidence that interpretation of results would differ with different durations of flexion. We hypothesized there would be no difference in interpretation of full hindlimb flexion for 5 or 60 seconds. Video recordings of lameness examinations of 34 client owned horses were performed that included: baseline lameness, upper hindlimb flexion for 60 seconds, and flexion of the same leg for 5 seconds. Videos were edited to blind reviewers to the hypothesis being tested. The baseline lameness video from each horse was paired with each flexion to make 2 pairs of videos for each case. Twenty video pairs were repeated to assess intra-observer repeatability. Fifteen experienced clinicians reviewed the videos and graded the response to flexion as either positive or negative. Potential associations between the duration of flexion and the likelihood of a positive flexion test were evaluated using generalized linear mixed models. A kappa value was calculated to assess the degree of intra-observer agreement on the repeated videos. Full hindlimb flexion of 60 seconds was more likely to be called positive than flexion of 5 seconds (p<0.0001), with the likelihood of the same interpretation 74% of the time. The first flexion performed was more likely to be called positive than subsequent flexions (p=0.029). Intra-assessor agreement averaged 75% with κ=0.49. Full hindlimb flexion of a horse for 5 seconds did not yield the same result as 60 seconds.

Objetivo: Avaliar a função da coluna cervical, utilizando testes clínicos cervicais em indivíduos com e sem Disfunção Temporomandibular (DTM) associados ou não ao relato de dor de cabeça. Métodos: Estudo Transversal. Foram avaliadas 57 mulheres com idade de 18 a 60 anos, divididas em dois grupos: DTM (n=40), e controle (n=17). Dada a alta frequência de relato de dor de cabeça a amostra de DTM foi estratificada em DTM com cefaleia (n=25) e DTM sem cefaleia (n=15). A incapacidade cervical foi avaliada pelo Índice de Incapacidade Cervical (NDI) e a dor na ATM pela Escala Visual Analógica de dor (EVA). A avaliação funcional da coluna cervical foi conduzida uma única avaliação por um examinador fisioterapeuta experiente e foi constituída pelos testes clínicos: análise da Amplitude de Movimento Ativa da Coluna Cervical (ADM); realização do Flexion-Rotation Test (FRT) e Cranio-Cervical Flexion Test (CCFT). Os sujeitos com DTM que relataram a presença de dores de cabeça foram instruídos a responder um questionário sobre as principais características da cefaleia referida. Para comparações entre os grupos foram aplicados ANOVA one way seguida por teste Post Hoc de Tukey ou por Teste Kruskall Wallis quando necessário. Para a análise de associação entre as variáveis categóricas foram aplicados Teste chi-quadrado ou Teste Exato de Fisher quando apropriado e para a análise de associação entre variáveis ordinais/contínua foram aplicados Testes de Correlação de Spearman. Resultados: Os indivíduos com DTM independente do relato de dor de cabeça apresentaram menor mobilidade no plano sagital, menores valores no FRT e apresentaram pior performance dos flexores profundos cervicais comparados aos controles (p<0.05). Além disso, os dados de ADM, FRT e CCFT foram associados com a intensidade de dor na ATM e a incapacidade cervical (p<0.01). Conclusão: Pacientes com DTM independente do relato de cefaleia apresentaram limitação na amplitude de flexão/extensão e do segmento C1-C2 da coluna cervical, além do menor desempenho dos músculos flexores profundos. Adicionalmente, a incapacidade cervical e a dor na ATM apresentaram correlação moderada com os testes funcionais cervicais nos indivíduos com DTM. / Objective: To evaluate the function of the cervical spine, using cervical clinical tests in individuals with and without Temporomandibular Disorders (TMD)associated or not to the report of headache. Methods: Were analyzed 57 women with age between 18 and 60 years, divided in two groups: TMD (n=40) and control (n=17). Given the high frequency of headache report, the TMD sample was stratified into TMD with headache (n=25) and TMD without headache (n=15). Cervical disability was assessed by the Neck Disability Index (NDI) and TMJ pain by the Visual Analogue Scale of pain (VAS). The functional evaluation of the cervical spine was conducted by a physiotherapeutic examiner with 10 years of experience and was constituted by the clinical tests: Analysis of the Cervical Range of Motion (CROM); Flexion-Rotation Test (FRT) and Craniocervical Flexion Test (CCFT). Subjects with TMD who reported the presence of headaches were instructed to answer 11 questions that contained the main characteristics of referred headache. For comparisons between control groups, TMD with Headache and TMD without Headache, ANOVA was applied one way followed by Tukey\'s Post Hoc test or by Kruskall Wallis test when necessary. For the analysis of association between the categorical variables, chi-square test or Fisher\'s exact test were applied when appropriate and for analysis of association between ordinal / continuous variables, Spearman\'s Correlation Tests were applied. Results: Individuals with TMD independent of headache report showed less mobility in the sagittal plane, lower values in FRT and showed worse performance of the deep cervical flexors compared to Controls (p<0.05). In addition, CROM, FRT and CCFT were associated with an intensity of TMJ pain and cervical disability (p <0.01). Conclusion: Patients with TMD independently of the headache report showed limited flexion / extension range and C1-C2 segment of the cervical spine, as well as deficits in the performance of the deep flexor muscles. In addition, a cervical disability and TMJ pain report showed a moderate correlation with the functional tests of FRT and CCFT in individuals with TMD.

Thèse doctorat : Génie des Matériaux : Villeurbanne, INSA : 1997. / Titre provenant de l'écran-titre. Bibliogr. p. 144-151.