Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2018-2019)

The proposed program of study validates a novel approach to locomotion energetics that promises to revolutionize the understanding of gait and its control. The intent is to use this novel approach for three basic objectives: 1) gain insight into some key aspects of locomotion dynamics and control, 2) demonstrate the value of using this novel approach (over the commonly applied standard approach), 3) formulate and validate energy-based models that allow prediction of human and animal locomotion in circumstances that have not previously been observed (ie. models that are not designed to replicate what is observed in organic systems but to anticipate how the system will respond because the model inputs are based on the factors that determine the functionally appropriate movement strategy). These latter objectives will be of value in predicting how people move in different circumstances, understanding the effect the form of any mammal has on its walking and running energetics and will be important in formulating models predicting the effects of surgical interventions or assistive devices on human mobility.

Mechanical energy is well recognized as an important aspect of locomotion function and control. However, when developing interpretive models explaining why particular gaits are utilized under specific circumstances, or explaining why humans or animals use their legs as they do, the most common approach focuses attention on the exchange between energy forms within the system (ie. within the individual or organism), so that energy from one portion of the gait cycle can be made available to another portion and does not need to be generated for each stride. Walking gaits are characterized based on gravitational potential energy to kinetic energy exchange systems (the inverted pendulum model) and running as strain potential energy to kinetic energy exchange systems (the spring-mass, pogo stick or spring loaded inverted pendulum model). All of these models focus on the degree of exchange between these energy types that occurs within the system. However, our work and those of a number of our colleagues, have determined that looking directly at how energy is lost from the system (the individual or organism) is a much more expedient and insightful approach. This program of study proposes a series of projects that continue this line of research with the purpose of clearly demonstrating its value, so assisting others in employing this research strategy, and to gain insight into some issues in locomotion energetics that we perceive as particularly important.

We believe that this work will serve to form a new foundation to understanding gait and its control, and will eventually have important applications in areas as diverse as gait rehabilitation and robotics design.