In walking and running, the arms and legs move like pendulums and produce regular, repeatable intervals, like clocks do. They also move at the same frequency. This research aims to further the understanding of the general principles behind this absolute coordination of pendular, clocking movements. Experiments in which people will swing hand-held pendulums of variable mass and length at their wrists will be concerned with the following kinds of issues: How is energy gained and lost by a movement cycle? How do these gains and losses relate across limbs? How does the amplitude of a movement cycle relate to its duration? How does preferred amplitude change with changes in mass and length? How many between-limb phase relations are possible, and how stable are they? How is absolute coordination to be defined in physical terms? The data will be analyzed through various formal methods of nonlinear dynamics. These results should facilitate the formal modeling of rhythmic activity. They should ultimately be useful in teaching various types of rhythmic physical activity and also in extending the basis for understanding the causes of rhythmic movement disorders.
