Human Gait Transition speeds predicted by fuzzy logic

What is a ground for an individual to change a gait from walking to running as a speed increases? A hypothesis about the energy-saving mechanism has not been approved. It was shown that both horses and humans prefer changing their gaits at speeds, which are not energetically favorable. The biomechanics of the gait change is not yet fully understood and there is a need for new models to deduce which body characteristics determine the transition speed. Diverse character of the human body is one of problems in modeling to overcome. The advantage of the fuzzy logic (FL) method is to cope with uncertainties in systems. Therefore we apply FL to predict Preferred Transition Speed (PTS) for a group of people with diverse kinetic parameters. We divided both kinetic parameters and PTS into four clusters, built membership functions, and logical rules with the logical operator AND accordingly. Body mass and height are found to be sufficient for PTS prediction. A Sugeno type FL model can predict the experimental PTS with a root mean square deviation equal to 0.08. The results justify an appropriateness of the FL method implications for PTS prediction suggesting that this method is valid for modeling human biomechanics.