SIMULATED CONTROL OF UNILATERAL, ANTICIPATORY LOCOMOTOR ADJUSTMENTS DURING OBSTRUCTED GAIT

Anticipatory adjustments of our locomotor patterns are necessary in or der to negotiate our uneven daily environments. Recent work (McFadyen and Winter 1991) has shown the re-organization of lower limb mechanics for obstacle avoidance during level walking. The present work describ es a model which sets the ground work for predicting how such re-organ ized motor patterns might be generated from stereotypic unobstructed p atterns. Pattern-generating algorithms use an estimation of future con tacts with obstacles to create weighting functions that modify joint a ngle trajectories towards new patterns capable of clearing the obstacl e. Feedforward/feedback control is then used to generate the necessary joint torques. The results show that model parameters can be found to generate not only kinematic but also energetic patterns for obstacle clearance that mimic experimental results. The validity of the model w ith respect to human locomotor control is discussed.