An Informational Algorithm as the Basis for Perception-Action Control of the Instantaneous Axes of the Knee

Traditional locomotion studies emphasize an optimization of the desired movement trajectories while ignoring sensory feedback. We propose an information based theory that locomotion is neither triggered nor commanded but controlled. The basis for this control is the information derived from perceiving oneself in the world. Control therefore lies in the human-environment system. In order to test this hypothesis, we derived a mathematical foundation characterizing the energy that is required to perform a rotational twist, with small amplitude, of the instantaneous axes of the knee (IAK). We have found that the joint’s perception of the ground reaction force may be replaced by the co-perception of muscle activation with appropriate intensities. This approach generated an accurate comparison with known joint forces and appears appropriate in so far as predicting the effect on the knee when it is free to twist about the IAK

Efeitos do Treino de Corrida Moderada na Capacidade de Reparacao da Cartilagem Articular Apos Lesao Mecanica Profunda Estudo Experimental no Rato

The purpose of this study was to investigate if mild running exercise results in improved repair of articular cartilage (AC) full-thickness defects. A perforation was created in a weight-bearing area of the medial femoral condyle in the rate knee. The animals were divided in two groups: intermittent active motion (IAM) and running training (RT) and sacrificed at two periods, four weeks (4wk) and eight weeks (8wk). The nature of the repair tissue besides having improved with time, was better in the training animals. The most common feature observed in the bonding to the adjacent cartilage was the existence of a clear gap between the repair tissue and the residual CA. Concerning the surface congruity the lower index of the RT group at 4 wk might suggest that in the beginning of the repair process a high load magnitude is not beneficial. This study might suggest that, the repair tissue can modulate in response to mechanical loading into a fibrocatilaginous tissue that resembles more the AC in the running animals, as shown by either improved collagen organization or increased amount of collagen (p<0,05-8 wk), and a increased amount of GAG (p<=0,05-4 wk)Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga