Determining mass centre trajectory variations for application to human modelling

Of the numerous man-model packages available for ergonomic evaluation, few have the capacity to correctly recreate human movement patterns under differing conditions without intervention from skilled operators. A manikin has been created within SWORDS, a constraint based modeller that produces unique movement patterns based on the conditions under which a movement occurs. For application to the manikin, this study established variations that occur in the mass centre horizontal trajectory due to changes in pace, posture and seat height, during sit-to-stand. Variations were considered in terms of events that occur throughout the motion. Regression equations were used in order to predict the occurrence of events under different conditions, and a mass centre trajectory was created by fitting a curve to the events.