Purpose： The purpose of this study was to examine the effects of landing kinematics and electromyographic （EMG） activities of medial gastrocnemius on a combined inversion and plantarflexion surface on the ankle （M...Purpose： The purpose of this study was to examine the effects of landing kinematics and electromyographic （EMG） activities of medial gastrocnemius on a combined inversion and plantarflexion surface on the ankle （MG）, peroneus longus （PL）, and tibialis anterior （TA） muscles. Methods： Twelve recreational athletes performed five drop landings from an overhead bar of 30 cm height on to three surfaces： a flat surface, a 25° inversion surface, and a combined surface of 25° inversion and 25° plantarflexion. The kinematic variables and integrated EMG （IEMG） of the three muscles were assessed using a one-way repeated measures ANOVA and a 3 × 3 （surface × muscle） ANOVA, respectively （p 〈 0.05）. Results： The IEMG results showed a significant muscle by surface interaction. The flat surface induced higher TA activity than the two tilted surfaces. The inverted surface produced significantly higher inversion peak angle and velocity than the flat surface, but similar PL activity across the surfaces. The MG IEMG, ankle plantarflexion angle, and inversion range of motion were significantly higher for the combined surface compared to the inverted surface. Conclusion： These findings suggest that compared to the inversion surface, the combined plantarflexion and inversion surface seems to provide a more unstable surface condition for lateral ankle sprains during landing.展开更多
We intend to establish how species diversity is dealt with, within the study of the ecosystem, in books for the 4th year of Compulsory Secondary Education, ESO （15-16 year-old students）. The analysis was carried out...We intend to establish how species diversity is dealt with, within the study of the ecosystem, in books for the 4th year of Compulsory Secondary Education, ESO （15-16 year-old students）. The analysis was carried out using a key issues dossier based on school science, which not only provides a description of reality, but also introduces a theoretical explanatory framework. Regarding species diversity, we focused on the descriptive approach, considering the link between diversity and trophic relationships, ecological succession and ecosystem stability through change, consequences for biodiversity of human activities and mechanisms to face such consequences; and on the explanatory perspective, which provides an interpretative answer for all the aspects previously mentioned. The findings drawn from textbooks show that biodiversity is linked both to the study of the ecosystem and to the impact of human societies on its maintenance. However, such study is particularly focused on the descriptive, rather than on the explanatory level. So, teachers should improve the study of biodiversity foresting a balance between descriptive and explanatory level.展开更多
文摘Purpose： The purpose of this study was to examine the effects of landing kinematics and electromyographic （EMG） activities of medial gastrocnemius on a combined inversion and plantarflexion surface on the ankle （MG）, peroneus longus （PL）, and tibialis anterior （TA） muscles. Methods： Twelve recreational athletes performed five drop landings from an overhead bar of 30 cm height on to three surfaces： a flat surface, a 25° inversion surface, and a combined surface of 25° inversion and 25° plantarflexion. The kinematic variables and integrated EMG （IEMG） of the three muscles were assessed using a one-way repeated measures ANOVA and a 3 × 3 （surface × muscle） ANOVA, respectively （p 〈 0.05）. Results： The IEMG results showed a significant muscle by surface interaction. The flat surface induced higher TA activity than the two tilted surfaces. The inverted surface produced significantly higher inversion peak angle and velocity than the flat surface, but similar PL activity across the surfaces. The MG IEMG, ankle plantarflexion angle, and inversion range of motion were significantly higher for the combined surface compared to the inverted surface. Conclusion： These findings suggest that compared to the inversion surface, the combined plantarflexion and inversion surface seems to provide a more unstable surface condition for lateral ankle sprains during landing.
文摘We intend to establish how species diversity is dealt with, within the study of the ecosystem, in books for the 4th year of Compulsory Secondary Education, ESO （15-16 year-old students）. The analysis was carried out using a key issues dossier based on school science, which not only provides a description of reality, but also introduces a theoretical explanatory framework. Regarding species diversity, we focused on the descriptive approach, considering the link between diversity and trophic relationships, ecological succession and ecosystem stability through change, consequences for biodiversity of human activities and mechanisms to face such consequences; and on the explanatory perspective, which provides an interpretative answer for all the aspects previously mentioned. The findings drawn from textbooks show that biodiversity is linked both to the study of the ecosystem and to the impact of human societies on its maintenance. However, such study is particularly focused on the descriptive, rather than on the explanatory level. So, teachers should improve the study of biodiversity foresting a balance between descriptive and explanatory level.
