Effects of immobilization and aquatic rehabilitation on the mechanical properties of gastrocnemius muscle of trained and sedentary female rats / Efeitos da imobilização e reabilitação aquática em propriedades mecânicas do músculo gastrocnêmio de ratas treinadas e sedentárias

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The skeletal muscle is a very adjustable structure and may present changes in response to functional demands. The aim of this study was to investigate the influence of physical training (swimming), sedentarism and the effects of immobilization and aquatic rehabilitation on the mechanical properties of the gastrocnemius muscle of trained and sedentary rats. Seventy female Wistar rats were allocated into seven experimental groups: group 1 (Control) - kept during 6 weeks in basal conditions; group 2 (Trained) - conditioned by a swimming program (resistance training) during six weeks; group 3 (Sedentary) - kept, during the same period, in small cages in which their mobility was restricted; group 4 (Trained-Immobilized) – previously trained with swimming and immobilized in a spica cast during a week; group 5 (Sedentary-Immobilized) - submitted to sedentarism and immobilized during a week; group 6 (Trained-Immobilized-Rehabilitated) physically trained, immobilized during a week and rehabilitated with swimming during two weeks; group 7 (Sedentary-Immobilized- Rehabilitated) - submitted to sedentarism, immobilized during a week and rehabilitated with the same protocol of the previous group. After this period, the animals were killed and the right gastrocnemius muscle was collected and mechanically tested in traction in a standard testing machine (EMIC). From the load versus deformation curves, the following mechanical parameters were obtained: load in the yield limit, ultimate load and stiffness. The results suggest that physical training caused favorable mechanical adaptations in the striated muscle. Conversely, sedentarism yielded a decrease in the mechanical parameters. Cast immobilization induced a decrease of mechanical parameters and, although the decrease was greater animals submitted to previous training, the mechanical parameters of trained rats were preserved in comparison to the sedentary animals. In addition, the rehabilitation program improved the muscular mechanical behavior and the previously trained animals showed a better recovery when compared with the sedentary rats

ASSUNTO(S)

músculo muscle propriedades mecânicas treinamento immobilization rat training mechanical properties sedentarismo rato imobilização sedentarism reabilitação

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