This thesis investigated whether different textured surfaces have a role to play in changing balance performance in healthy young and older adults. A review of the literature showed that balance may be improved by standing on surfaces, or wearing foot insoles, with texture compared to those that are smooth, possibly by providing enhanced plantar tactile stimulation. It also showed that textured footwear interventions can influence lower limb muscle activity during functional activities. However, some major gaps in current literature were identified. There was limited evidence relating to the effect of texture in older adults: a population known to show poor balance and at high risk of falling. The importance of the geometric textured pattern in changing balance had not been investigated. It was also unclear whether textured interventions altered lower limb muscle activity, as a component of sensorimotor function of balance control. The purpose of this thesis was to address these important areas of research and contribute novel evidence to the field. In two separate studies, 24 young and 50 older healthy adults conducted tests of bilateral quiet standing with eyes open and closed on two different textured surfaces and a smooth surface as control. Centre of pressure based sway variables were extracted from a force platform and lower limb muscle activity was collected using surface electromyography, over 30 seconds. Textured surfaces did not significantly alter sway variables or lower limb muscle activity in healthy young adults. Closer observation of the data tentatively suggested texture may have the capacity to alter anterior-posterior sway and centre of pressure velocity in young adults. These findings supported the aims of this thesis to explore the possibility of a textured effect in people with poor balance ability: older adults. Textured surfaces significantly changed mediolateral sway range and centre of pressure velocity in healthy older adults, in the absence of visual information. No significant changes were observed for lower limb muscle activity, between the textured conditions. Exploratory sub-group analysis for gender generated speculative data suggesting the effect of texture on balance and muscle activity may be more marked in older females. Evidence from both studies suggests that relative to control, the two textured conditions have opposite effects on postural sway. There may be an optimal textured pattern which could be therapeutically beneficial for enhancing balance performance in healthy and pathological groups. Further investigation is required.

xiv, 96 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Among older adults, an impaired ability to maintain balance while simultaneously performing cognitive tasks is a common occurrence. Because poor dual-task balance performance is associated with increased fall risk and a decline in cognitive function, interventions to improve dual-task balance performance are needed. Although traditional rehabilitation programs emphasizing training balance under single-task conditions are effective in improving single-task balance performance, it is not known whether single-task training generalizes to balance control under dual-task contexts. Moreover, the effectiveness of approaches to training balance under dual-task conditions is not known. Thus, the purposes of this study were to determine whether elderly individuals with balance impairment can improve their balance performance under dual-task conditions; to investigate whether training balance under single-task conditions generalizes to balance control during dual-task contexts; and to evaluate the effect of instructional set on dual-task balance performance. Specifically, the efficiency of three different training strategies was examined in an effort to understand the mechanisms underlying training-related changes in dual-task balance performance. Twenty-three elderly adults with balance impairment were randomly assigned to 1 of 3 interventions: single-task balance training (ST); dual-task training with fixed-priority instruction (FP); and dual-task training with variable-priority instruction (VP). Clinical and laboratory measures were obtained at baseline and after training. In addition, selected clinical outcomes were repeated after the second week of training to examine interim balance change and at twelve weeks post training to test retention. Results indicate that dual-task training was effective in improving balance under dual-task conditions in the elderly with balance impairment. Training balance under single-task conditions may not generalize to balance control during dual-task contexts. Explicit instruction regarding attentional focus was an important factor for improvement in dual-task performance. The VP instructional set offered advantages over the FP instructional set in terms of the degree of improvement, the rate of learning, and the retention of the dual-task training effect. The dual-task processing skills learned during training were not transferred to novel dual-task conditions. Lastly, the training benefits acquired during VP training could be the result of both automatization of the individual task and the development of task-coordination skills. / Adviser: Marjorie Woollacott

Made available in DSpace on 2014-12-17T15:16:18Z (GMT). No. of bitstreams: 1 CarolinaRBPS_DISSERT.pdf: 1729763 bytes, checksum: 2027dc4e234a848af977bb622335d04e (MD5) Previous issue date: 2012-12-20 / The aging process modifies various systems in the body, leading to changes in mobility, balance and muscle strength. This can cause a drop in the elderly, or not changing the perceived self-efficacy in preventing falls. Objective: To compare the mobility, body balance and muscle performance according to self-efficacy for falls in community-dwelling elderly. Methods: A cross-sectional comparative study with 63 older (65-80 years) community. Were evaluated for identification data and sociodemographic, cognitive screening using the Mini Mental State Examination (MMSE), effective for the fall of Falls Efficacy Scale International Brazil (FES-I-BRAZIL), Mobility through the Timed Up and Go Test , the balance Berg Balance Scale (BBS) and the Modified Clinical Test tests of Sensory Interaction on Balance (mCTSIB), tandem walk (TW) and Sit to Stand (STS) of the Balance Master? System. Finally, muscle performance by using isokinetic dynamometry. Statistical analysis was performed Student t test for comparison between groups, with p value ≤ 0.05. Results: Comparing the elderly with low-efficacy for falls with high-efficacy for falls, we found significant differences only for the variable Timed Up and Go Test (p = 0.04). With regard to data on balance tests were significant differences in the speed of oscillation firm surface eyes open modified Clinical Test of Sensory Interaction on Test of Balance (p = 0.01). Variables to isokinetic dynamometry were no significant differences in movement knee extension, as regards the variables peak torque (p = 0.04) and power (p = 0.03). Conclusion: The results suggest that, compared to older community with low-and high-efficacy for falls, we observed differences in variables related to mobility, balance and muscle function / O processo de envelhecimento modifica diversos sistemas do organismo, levando a altera??es de mobilidade, equil?brio e for?a muscular. Isto pode ocasionar a queda no idoso, alterando ou n?o a auto-efic?cia percebida em evitar quedas. Objetivo: Comparar a mobilidade, equil?brio corporal e desempenho muscular segundo a auto-efic?cia para quedas em idosas residentes na comunidade. Material e m?todos: Estudo comparativo de corte transversal, com 63 idosas (65-80 anos) comunit?rias. Foram avaliadas quanto aos dados de identifica??o e s?ciodemogr?ficos, rastreio cognitivo pelo Mini Exame do Estado Mental (MEEM), efic?cia para quedas pela Escala de Efic?cia de Quedas Internacional Brasil, (FES-I-BRASIL), mobilidade atrav?s do Timed Up and Go Test, equil?brio pela Escala de Equil?brio de Berg (EEB) e pelos testes Modified Clinical Test of Sensory Interaction on Balance (mCTSIB), Tandem walk (TW) e Sit to Stand (STS) do Balance Master System?. Por fim, o desempenho muscular por dinamometria isocin?tica. Na an?lise estat?stica foi realizado teste t de Student para compara??o entre grupos, com p valor ≤ 0,05. Resultados: Comparando as idosas com baixa-efic?cia para quedas com as com alta-efic?cia para quedas, encontrou-se diferen?a significativa apenas para a vari?vel Timed Up and Go Test (p=0,04). Quanto aos dados relativos aos testes de equil?brio foram encontradas diferen?as significativas na velocidade de oscila??o superf?cie firme olhos abertos do teste modified Clinical Test of Sensory Interaction on Balance (p=0,01).Para as vari?veis da dinamometria isocin?tica foram encontradas diferen?as significativas no movimento de extens?o do joelho, no que diz respeito as vari?veis pico de torque (p=0,04) e pot?ncia (p=0,03). Conclus?o: Os resultados sugerem que, comparando idosas de comunidade com baixa e alta-efic?cia para quedas, observou-se diferen?as nas vari?veis relacionadas ? mobilidade, equil?brio e fun??o muscular

Made available in DSpace on 2014-07-29T15:13:54Z (GMT). No. of bitstreams: 1 Tese rubens.pdf: 400903 bytes, checksum: b882c01250cd635fb63fe5a931e6cd24 (MD5) Previous issue date: 2009-12-17 / Three research works were conducted in order to determine the chemical composition, nutrient and energy digestibility, apparent metabolizable energy (EMA) and apparent metabolizable energy corrected by nitrogen retention (EMAn) of babaçu cake, as well as to evaluate the results of its use on performance and carcass traits of Label Rouge chicks. The first experiment consisted a biological assay carried where the traditional total feces collection method was used to characterize babaçu cake bromatologically, as well as to determine its energy levels and metabolizability coefficients. Seventy two Label Rouge day-old-chicks where placed in metallic batteries and at the 14th day they where assigned to a randomized block design with two treatments and six replicates of 6 birds each. The results found where: Crude energy = 5,056 kcal/kg, Crude protein = 18.8%, Crude fiber = 29.50%, Ether extract = 8.8%, Calcium = 0.19%, Phosphorus = 0.67%, EMA= 2,650 kcal/kg and EMAn=2,580 kcal/kg. The dry matters, Crude energy s and ether extract s apparent coefficient of metabolizability were 31.72%; 46.78%; 92.35%, respectively. The nitrogen balance of reference diet and test diet where respectively 15.90% and 6.54%. The second research work was conducted aiming to evaluate the effect of different levels of inclusion of babaçu cake in diets based on corn and soybean meal on the performance of free range chickens from 1 to 7, 1 to 14, 1 to 21 and 1 to 28 days old. Three hundred day-old (male and female) Label Rouge chickens, were assigned to a completely randomized design with five treatments (0, 8, 16, 24 and 32% of inclusion of babaçu cake) and four replicates of 15 birds each. Inclusion levels of babaçu cake influenced feed intake at ages 1 to 7 days (P=0.0031) and did not influence other ages. Live weight and weight gain were influenced at age 1 to 7 days when it was used the SNK test for mean comparison. Live weight was affected at ages 1 to 14 (P=0.0003), 1 to 21 (P=0.0028) and 1 to 28 (P=0.0168) days old, as well as weight gain at ages 1 to 14 (P=0.0004), 1 to 21 (P=0.0037) and 1 to 28 (P=0.0196) days old. Feed convertion was affected at ages 1 to 7 (P≤0.0001) and 1 to 28 (P=0.0027).The third research work was aimed to evaluate the effect of different levels of inclusion of babaçu cake on performance, carcass yield and carcass protein and fat deposition of Label Rouge broiler chicks that received the experimental diets from 36 to 84 days old. Three hundred and sixty birds (male and female) were assigned to a completely randomized design with five treatments (0, 8, 16, 24 and 32% of inclusion of babaçu cake) and four replicates of 18 birds each. Weight at 84 days old and weight gain were not influenced by the different levels of babaçu cake, however feed intake increased (P= 0.002) and feed convertion was negatively affected (P=0.052) by crescent levels of babaçu cake in the diets. Carcass yield, carcass fat and protein deposition and abdominal fat deposition weren´t influenced as the inclusion levels of babaçu cake increased. It is possible the use of up to 32% of inclusion of babaçu cake in the diet of Label Rouge broiler chicks from 36 to 84 days old / Foram conduzidos três experimentos para determinar a composição química e os valores de energia metabolizável da torta de babaçu, avaliar seu emprego para desempenho zootécnico e características de carcaça de frangos Label Rouge. Na primeira pesquisa, foi realizado ensaio metabólico, utilizando-se o método tradicional de coleta total de excretas, para caracterizar bromatologicamente a torta de babaçu, determinar os valores de EMA, EMAn e coeficientes de metabolização. Foram alojados 72 pintos Label Rouge, com um dia de idade, em baterias metálicas, distribuídos em delineamento inteiramente casualizado com dois tratamentos e seis repetições de seis aves cada. Como resultados: EB = 5.056 kcal/kg, PB = 18,8%, FB = 29,50%, EE = 8,8%, Ca = 0,19%, P = 0,67%. Determinou-se: EMA = 2.650 kcal/kg, EMAn = 2.580 kcal/kg, CMAMS = 31,72%, CMAEB = 46,78% e do Extrato etéreo = 92,35. O segundo experimento foi realizado para avaliar o efeito de diferentes níveis de inclusão da torta de babaçu, no desempenho de frangos Label Rouge, nos períodos de 1 a 7, 1 a 14, 1 a 21 e 1 a 28 dias de idade. Foram alojados trezentos pintos de um dia (machos e fêmeas), distribuídos em delineamento inteiramente casualizado com cinco tratamentos (0, 8, 16, 24 e 32% de inclusão) e quatro repetições de quinze aves cada. A inclusão afetou o consumo das rações, nos períodos de 1 a 7 dias (P=0,0031), não alterando para os demais períodos. O peso vivo e o ganho de peso das aves foram afetados no período de 1 a 7 dias de idade, quando se ajustaram os dados pelo SNK, para comparar as médias dos tratamentos. O peso vivo foi afetado, ainda, nos períodos de 1 a 14 (P=0,0003), de 1 a 21 (P=0,0028) e de 1 a 28 (P=0,0168) dias de idade, bem como o ganho de peso, nos períodos de 1 a 14 (P=0,0004), de 1 a 21 (P=0,0037) e de 1 a 28 (P=0,0196) dias de idade. A conversão alimentar foi afetada nos períodos de 1 a 7 (P≤0,0001) e de 1 a 28 (P=0,0027). O terceiro experimento objetivou avaliar o efeito da inclusão da torta de babaçu em dietas de frangos Label Rouge, de 36 a 84 dias de idade. Alojaram-se 360 frangos (machos e fêmeas), em delineamento inteiramente casualizado com cinco tratamentos (0, 8, 16, 24 e 32% de inclusão) e quatro repetições de dezoito aves cada. Procedeu-se os resultados à análise de variância com o pacote estatístico SAS, submetendo-se as diferenças significativas à análise de regressão polinomial. Não ocorreu efeito para peso, ganho de peso, mas houve aumento no consumo de ração (P=0,002) e menor conversão alimentar (P=0,052), conforme o nível de inclusão aumentou. O rendimento de carcaça, a gordura abdominal, a deposição de proteína e de lipídios na carcaça não foram afetados. Conclui-se que a torta de babaçu pode ser caracterizada como alimento proteico (PB=18,8%) volumoso (FB=29,5), com EMA=2.650kcal/kg e seus altos teores de fibras indicam precaução de sua inclusão, recomendando-se até 8% para Label Rouge de 1 a 28 dias de idade e até 32% entre 36 e 84 dias de idade