Stroke is the leading cause of disability worldwide. It often leads to mobility limitations resulting from deficits in muscle performance. While reduced muscle strength and rate of force production have been reported, little is known about the power generating capability of people after stroke and its relationship to mobility. Research in other populations has found that measures of muscle power may have a greater association with activity performance than do measures of muscle force alone. Consequently, in an attempt to optimise power, investigators have focused on identifying ideal parameters within which to train for power. One such parameter is the identification of the loading level at which maximal power is generated. Literature reporting optimal loads from both young athletic and healthy older populations has yielded mixed results, making the applicability to a hemiparetic population difficult. The purpose of this study was to investigate muscle power performance at differing loads and to determine at what load muscle power is best elicited in hemiparetic and age and gender matched control groups. A secondary aim was to ascertain whether there is a relationship between the muscle power values obtained and activities such as gait, stair climbing and standing from a chair. Twenty nine hemiparetic volunteers and twenty nine age and gender matched controls were evaluated. Involved and uninvolved legs of the stroke group and a comparison leg of the control group underwent testing. Leg press muscle power was measured using a modified supine leg press machine at 30%, 50% and 70% of a one-repetition maximum (1-RM) load. Participants were positioned on the leg press machine and asked to push, with a single leg, as hard and as fast as they could. Data was collected via a mounted force platform and a linear transducer connected to a platform on which the participants lay. From these, power was able to be calculated. The activities were timed while being performed as fast as possible. The results showed that peak muscle power values differed significantly between the involved, uninvolved and control legs. Peak leg power in all three leg groups was greatest when pushing against a load of 30% of 1-RM. Involved leg peak power tested at 30% of 1-RM (Mean:240; SD:145 W) was significantly lower (p<0.05) than the uninvolved leg (Mean:506; SD:243 W). Both the involved and uninvolved legs generated significantly lower peak power (p<0.05) than the control leg (Mean:757; SD:292 W). Correlations were found between the involved leg peak power and gait speed and involved leg peak power and stair climbing (r=0.6-0.7, p<0.05). No correlation was found between paretic leg peak power and chair stands. The control group leg peak power demonstrated significant associations with the performance of all three activities.In summary, there were significant differences between the involved and the uninvolved leg in power production after stroke. As well, there are significant differences between the uninvolved leg and the leg of those not affected by stroke. Power was related to a number of activities.

Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Feb. 12, 2009). Includes bibliographical references (p. 35-43).

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed June 6, 2008). Includes bibliographical references (p. 85-97).

Thesis (Ph.D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed on June 24, 2009). Includes bibliographical references.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Includes bibliographical references (p. 85-97). Also available online.

Thesis (D.P.H.)--University of Alabama at Birmingham, 2010. / Title from PDF title page (viewed on July 1, 2010). Includes bibliographical references.

Thesis (M.Tech.: Radiography)-Dept. of Radiography, Durban University of Technology, 2007 xxiv, 142 leaves, Annexures A-L / The aim of the study was to evaluate CT-based treatment planning versus digitised image planning (standard planning technique) for carcinoma of the breast, using the four-field breast technique, in terms of the depth of supraclavicular and axillary nodes, the variability of the breast tissue and the dose inhomogeneity at the matchline.

p. 1-121 / Submitted by Antonio Geraldo Couto Barreto (ppgms@ufba.br) on 2013-10-03T14:33:30Z No. of bitstreams: 1 tese versão final enviada à gráfica.pdf: 1334625 bytes, checksum: 705001111bc4ab96e416b5ae88c938cb (MD5) / Approved for entry into archive by Patricia Barroso(pbarroso@ufba.br) on 2013-10-03T18:03:38Z (GMT) No. of bitstreams: 1 tese versão final enviada à gráfica.pdf: 1334625 bytes, checksum: 705001111bc4ab96e416b5ae88c938cb (MD5) / Made available in DSpace on 2013-10-03T18:03:38Z (GMT). No. of bitstreams: 1 tese versão final enviada à gráfica.pdf: 1334625 bytes, checksum: 705001111bc4ab96e416b5ae88c938cb (MD5) Previous issue date: 2013 / Objetivo:Observar a prevalência do tabagismo entre adolescentes no Brasil;analisar fatores de risco ao tabagismo.Métodos:Estudo descritivo observacional e estudo de corte transversal. Foram pesquisados estudos de corte transversal ou coorte nos últimos 40anos,contendo percentuais de prevalência e/ou experimentação nos bancos de dados:MEDLINE, SciELO, LILACS e PubMeD; por busca ativa e comunicados oficiais,sendo selecionados 84 trabalhos.Foi realizado estudo de corte transversal de agosto a dezembro de 2011 com 781 estudantes do ensino público/privado de Campina Grande-PB.A análise estatística utilizou-se do ambiente computacional R versão 2.15.0, teste qui-quadrado, intervalo de confiança e regressão logística ao nível de confiança de 5%.Resultados:Houve redução acentuada daprevalência do tabagismo na população brasileira entre o final da década de 80 até metade da década de 2000,mas menor variação posteriormente;redução da prevalência entre jovens e aumento percentualde mulheres tabagistas.Nas regiões brasileiras,houve redução no Sudeste, Sul e Nordeste e aumento no Centro-Oeste.A prevalência entre adolescentes brasileiros foi semelhante ou menor do que a da maioria dos países avaliados.Os fatores que fomentam o tabagismo estão relacionados à convivência com fumantes e usuários de outras drogas psicoativas ou utilizá-las,fácil acesso,propaganda,inexistência ou não cumprimento de leis antitabagismo, inexistência de campanhas de prevenção. Na cidade avaliada,a prevalência de escolares tabagistas foi de 9,8%.Destes,2,9% eram regulares,2,8%, ocasionais e 4,1% regulares e ocasionais simultaneamente.O percentual de experimentação foi de 31,2%,o de tabagistas atuais de 6,0%e ex-tabagistas 4,6%.Fumantes passivos foram 68%.Os fatores influentes foram:conviver com fumantes, ser indiferente ao controle da venda,achar desnecessário o aumento da fiscalização e ver menores comprando cigarros. Conclusão:A prevalência do tabagismo entre jovens no Brasil foi baixa,comparando-se com outros países,sendo altos experimentação e tabagismo passivo;houve aumento da prevalência no sexo feminino.Os fatores influentes no tabagismo estão ligados ao convívio com tabagistas e à inexistência ou ausência de rigor no cumprimento das leis antitabagismo dirigidas a essa faixa etária. / Salvador

Carta al editor / Revisión por pares