Thesis (doctoral)--University of Copenhagen.

No description available.

It has been shown that maximal, bilateral efforts result in both a force and EMG deficit when compared to maximal, unilateral activation of the same musculature. It is unclear whether this deficit is the result of interactions of central or peripheral origin. The first aim study investigated the bilateral performance index (BPI (%) = [100 x bilateral force/(right unilateral + left unilateral forces)] - 100) for maximal, isometric, extensor torques about the knee joint in three groups of subjects: untrained (never lifted weights), cyclists (leg musculature trained reciprocally), and weightlifters (legs trained bilaterally). The BPI for the weightlifters (+7.0 ± 5.0%) was significantly (p < 0.05) greater than the BPI of the cyclists (-4.0 ± 6.3%) or the untrained subjects (-9.7 ± 5.2%). These results indicate that the inhibitory mechanisms previously proposed to act during bilateral efforts are inadequate, and that excitatory factors must be present to achieve a BPI > 0. The second aim study showed that the BPI can be altered as a result of three weeks of bilateral isometric strength training. The BPI's for the control and unilateral training groups were not significantly different pre- to posttraining. However, the BPI of the bilateral training group increased significantly (p < 0.05) from -3.7 ± 6.9% prior to training, to +4.2 ± 4.4% after training. These findings indicate that bilateral strength training can alter the relationship between unilateral and bilateral force output. The third aim study demonstrated that subjects with a positive BPI (+6.8 ± 4.3%) responded differently to an afferent perturbation (electrical stimulation) than subjects with a negative BPI (-10.0 ± 5.2%). The negative BPI group showed a 5.7 ± 3.4% facilitation in force during contralateral electrical stimulation. This was significantly (p < 0.05) less than the 16.5 ± 7.5% facilitation shown by the positive BPI group. These results indicate that afferent feedback can alter the force output in the contralateral limb, and may thereby play a role in unilateral-bilateral force differences.

by Sze, Lung Yam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 106-112). / Abstract --- p.i / Acknowledgements --- p.iv / Contents --- p.v / Chapter Chapter 1 --- General Introduction / Chapter 1.1. --- Morphology of the Mammalian Somite and Limb --- p.1 / Chapter 1.1.1. --- The Somite --- p.1 / Chapter 1.1.2. --- The Limb --- p.3 / Chapter 1.2. --- Somite-Limb Relationship --- p.5 / Chapter 1.2.1. --- Somite Contribution to the Appendicular Musculature --- p.5 / Chapter 1.2.2. --- Somite Contribution to Limb Morphogenesis --- p.6 / Chapter 1.3. --- Control of Directionality of Somitic Cell Migration in Appendicular Environment --- p.8 / Chapter 1.4. --- Reasons and Objective of the Present Study --- p.10 / Chapter Chapter 2 --- The Origin of the Mammalian Limb Skeletal Muscles / Chapter 2.1. --- Introduction --- p.16 / Chapter 2.2. --- Materials and Methods --- p.19 / Chapter 2.2.1. --- Embryo Collection --- p.19 / Chapter 2.2.2. --- Isolation of Somites --- p.20 / Chapter 2.2.3. --- DiI-labelling of Rat Donor Somites --- p.21 / Chapter 2.2.4. --- Somite Transplantation --- p.21 / Chapter 2.2.5. --- Embryo Culture --- p.22 / Chapter 2.2.6. --- Analysis of Cultured Embryos --- p.22 / Chapter 2.2.7. --- Cryosection --- p.23 / Chapter 2.2.8. --- Limb Explant Cultures --- p.23 / Chapter 2.2.9. --- Immunohistochemistry --- p.24 / Chapter 2.2.10. --- X-gal Staining --- p.25 / Chapter 2.2.11. --- Histology --- p.25 / Chapter 2.3. --- Results --- p.27 / Chapter 2.3.1. --- Gross Morphology of Cultured Embryos --- p.27 / Chapter 2.3.2. --- Distribution of DiI Labelled Somitic Cells in Rat Embryos --- p.27 / Chapter 2.3.3. --- Histogenetic Potential of Labelled Somitic Cells in the Limbs --- p.29 / Chapter 2.3.4. --- Chimeaic Limb Culture --- p.30 / Chapter 2.4. --- Discussion --- p.32 / Chapter 2.4.1. --- Relationship Between the Somites and the Limb Musculature in Rat Embryos --- p.33 / Chapter 2.4.2. --- Myogenic Potential of Somitic Cells in the Mouse Limb Bud --- p.36 / Chapter 2.4.3. --- The Regulatory Potentials of Mammalian Somites --- p.37 / Chapter Chapter 3 --- The Migration of Somitic Cells into the Mammalian Fore- limb Bud / Chapter 3.1. --- Introduction --- p.52 / Chapter 3.2. --- Materials and Methods --- p.57 / Chapter 3.2.1. --- Embryo Collection --- p.57 / Chapter 3.2.2. --- Embryo Culture and Analysis of Cultured Embryos --- p.58 / Chapter 3.2.3. --- Experimental Series I --- p.58 / Chapter A. --- Micro-injection of DiI --- p.58 / Chapter B. --- Explant Cultures of Rat Fore-limb Bud --- p.59 / Chapter C. --- Histology and Immunohistochemistry --- p.60 / Chapter 3.2.4. --- Experimental Series II --- p.61 / Chapter A. --- Preparation of Conditioned and Unconditioned Medium --- p.61 / Chapter B. --- Coating of Nucleopore Membrane with Fibronectin --- p.62 / Chapter C. --- Preparation of Somitic Cells --- p.62 / Chapter D. --- Analysis of Chemotatic Effect --- p.63 / Chapter 3.2.5. --- Experiment Series III --- p.64 / Chapter A. --- Micro-injection of Latex Beads --- p.64 / Chapter B. --- Isolation of Somatopleure and Transplantation --- p.64 / Chapter C. --- "Somite Isolation, Labelling, and Transplantation" --- p.65 / Chapter D. --- Histology --- p.65 / Chapter 3.3. --- Results --- p.66 / Chapter 3.3.1. --- Development of Embryos In vitro --- p.66 / Chapter 3.3.2. --- Experimental Series I --- p.66 / Chapter A. --- Distribution of Somitic Cells in DiI Injected Embryos --- p.66 / Chapter B. --- Histogenetic Potential of Limb Explants Cultured Under the Kidney Capsule --- p.68 / Chapter C. --- Histogenetic Potential of Limb Explants Cultured In vitro --- p.69 / Chapter 3.3.3. --- Experimental Series II --- p.70 / Chapter A. --- Chemotatic Behaviour of Somitic Cells --- p.70 / Chapter 3.3.4. --- Experimental Series III --- p.71 / Chapter A. --- Ability of Latex Beads to Invade the Limb Bud --- p.71 / Chapter B. --- Distribution Pattern of Somatopleural and Somitic Cells --- p.71 / Chapter 3.4. --- Discussion --- p.75 / Chapter 3.4.1. --- Experimental Series I --- p.75 / Chapter A. --- Distribution of Somitic Cells in DiI-Injected Rat Embryos --- p.75 / Chapter B. --- Histogenetic Potential of Rat Fore-limb Bud --- p.77 / Chapter 3.4.2. --- Experimental Series II --- p.80 / Chapter A. --- Chemotatic Behaviour of Somitic Cells --- p.80 / Chapter 3.4.3. --- Experimental Series III --- p.80 / Chapter A. --- Ability of Latex Beads to Invade the Limb Bud --- p.80 / Chapter B. --- Ability of Somatopleure and Somite to Invade Limb Bud --- p.83 / Chapter 3.4.4. --- Conclusion --- p.83 / References --- p.106 / Appendix --- p.113

by Tang Mei Kuen. / "May 1999." / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 134-179). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

This study applies the Washington State Ergonomics Tool to waste industry jobs in Texas. Exposure data were collected by on-site observation of fourteen different multi-task jobs in a major national solid waste management company employing more than 26,000 employees. This company has nationwide operations, and these jobs represent the majority of workers involved in the collection and processing of solid waste. The WSET uses observational checklist methodology to evaluate generic risk factors in the following six major categories: awkward posture, highly repetitive motion, high hand force, repeated impact, lifting, and hand-arm vibration. The assessment tool incorporates these risk factors and combinations of risk factors into checklists for identifying three levels of potential exposure: safe, -caution zone" and -hazard zone" jobs. The tool was developed for employers to use in determining whether a job was likely to increase the risk of workplace musculoskeletal disorders (WMSDs) to their employees. OSHA 200 logs were used as the main source of morbidity data. If there was one recorded WMSD, the job was classified as -positive. "If there was no recorded WMSD, the job was classified as -negative. "-Safe"jobs were those predicted not to expose workers to increased risk of WMSDs. Those that possessed one or more -caution zone"criteria but still fell below the -hazard zone" threshold required the employer to provide -awareness education" for employees and to further analyze the job for the presence of -hazard zone" risk factors. If hazard zone risk factors were not present, no further action was required. Jobs that upon further analysis possessed one or more of the -hazard zone"criteria were labeled -hazardous" jobs. If the further analysis shows the presence of risk factors established in the hazard zone criteria (Appendix B), the employer would be required to take corrective action to reduce exposures to below the hazardous level. Of the three jobs predicted to be -safe"by -caution zone" criteria, two did not have injuries and one did. Of the eleven jobs predicted by -caution zone"criteria to increase the risk of WMSDs, six resulted in injuries and five did not. Of the four jobs predicted by -hazard zone"criteria to be -problem"jobs, two jobs did result in injury and two did not. This study found that the WSET -caution zone"criteria were more effective at predicting which jobs were likely to increase the risk of WMSDs than was the -hazard zone"checklist. The caution zone had high sensitivity and low specificity. The hazard zone criteria reflect a low sensitivity and a low specificity. Further analysis revealed the WSET was helpful in predicting back injuries associated with lifting but not effective at predicting jobs with the potential for upper extremity injuries.

This study applies the Washington State Ergonomics Tool to waste industry jobs in Texas. Exposure data were collected by on-site observation of fourteen different multi-task jobs in a major national solid waste management company employing more than 26,000 employees. This company has nationwide operations, and these jobs represent the majority of workers involved in the collection and processing of solid waste. The WSET uses observational checklist methodology to evaluate generic risk factors in the following six major categories: awkward posture, highly repetitive motion, high hand force, repeated impact, lifting, and hand-arm vibration. The assessment tool incorporates these risk factors and combinations of risk factors into checklists for identifying three levels of potential exposure: safe, -caution zone" and -hazard zone" jobs. The tool was developed for employers to use in determining whether a job was likely to increase the risk of workplace musculoskeletal disorders (WMSDs) to their employees. OSHA 200 logs were used as the main source of morbidity data. If there was one recorded WMSD, the job was classified as -positive. "If there was no recorded WMSD, the job was classified as -negative. "-Safe"jobs were those predicted not to expose workers to increased risk of WMSDs. Those that possessed one or more -caution zone"criteria but still fell below the -hazard zone" threshold required the employer to provide -awareness education" for employees and to further analyze the job for the presence of -hazard zone" risk factors. If hazard zone risk factors were not present, no further action was required. Jobs that upon further analysis possessed one or more of the -hazard zone"criteria were labeled -hazardous" jobs. If the further analysis shows the presence of risk factors established in the hazard zone criteria (Appendix B), the employer would be required to take corrective action to reduce exposures to below the hazardous level. Of the three jobs predicted to be -safe"by -caution zone" criteria, two did not have injuries and one did. Of the eleven jobs predicted by -caution zone"criteria to increase the risk of WMSDs, six resulted in injuries and five did not. Of the four jobs predicted by -hazard zone"criteria to be -problem"jobs, two jobs did result in injury and two did not. This study found that the WSET -caution zone"criteria were more effective at predicting which jobs were likely to increase the risk of WMSDs than was the -hazard zone"checklist. The caution zone had high sensitivity and low specificity. The hazard zone criteria reflect a low sensitivity and a low specificity. Further analysis revealed the WSET was helpful in predicting back injuries associated with lifting but not effective at predicting jobs with the potential for upper extremity injuries.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Biomedical Engineering." Includes bibliographical references (p. 95-99).

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xv, 239 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2004. / Vita. Bibliography: 127-146.