Momentos articulares resultantes durante o andar e o correr de crianças / Net joint moments during walking and running of children

The purpose of this study is to describe net joint moments for two types of locomotor movements in children: walking and running. Net joint moments can be considered as causes of the movement and their study contributes to a better understanding of movement coordination processes and also of the loading characteristics of locomotor movements. Net joint moments were estimated for the ankle and knee joints at the sagittal and frontal planes during walking and running in children aged 6.5 in average. The patterns were compared to an adult pattern in order to show the importance of loading control during locomotor movements. Ground reaction forces were measured with a Kistler force plate and the segmentar positions were measured with the Selspot II system. Both were synchronized and sampled at 250 Hz. The combination of these measurements with the mathematical relations of the joints allowed the estirnation of the net joint moments. A scaling procedure for the net joint moments was also considered when comparing the patterns of the child with those of the adult, because the magnitudes of the moments are very sensitive to differences in the length of the lower limbs. The Quantitative results are very similar to those from other studies, which used more complex models. The high variability of joint moments requires an intra-individual approach for the evaluation of results.

Estudo das diferencas de energia mecanica entre o andar e o correr em diferentes velocidades na esteira rolante / Mechanical energy differences between walking and rinning at different velocities on tradmill

CAVANAH(1990) relatou uma variacao de 170 a 1700 w na potencia da corrida entre3,3 e 3,9m/s,isto calculado por seis diferentes autores.O objetivo deste trabalho foi analisar as curvas de energia mecanica de seis individuos para o andar e o correr.Os individuos foram filmados enquanto andavam a 1,5m/s e corriam a 3,0 e 4,0m/s na esteira rolante.As componentes de energia mecanica foram calculadas se utilizando as equacoes descritas por ZATSIORSKY et al.(1987(.Com relacao as diferencas entre o andar e o correr:a) no andar a maior contribuicao para a alteracao total advem da energia interna,enquanto para a corrida deriva da energia externa;b)a energia interna e externa estao em fase no andar e em oposicao no correr.Ao comparar as variacao e entre as duas velocidades de corrida:a)com o aumento da velocidade,o aumento medio da contribuicao da energia interna para a alteracao total foi de em torno de 72 e da energia externa de 36;b)nao houve alteracao na contribuicao da energia potencial para a energia externa;c)o aumento na energia interna era principalmente dependente do aumento na energia cinetica