Teach-in 2000 : Juggling as a Gait Analogy
by Chris Kirtley, The Catholic University of America, Washington DC

Juggling can be broadly interpretted to include pretty much any action that controls the motions of flying objects by catching, throwing, or hitting. Thus walking is a kind of self-juggling, with the feet being the objects being juggled!

Empirical and formal analyses of juggling have shown that to obtain stable rhythmic performance, skilled actors obey principles as defined by nonlinear dynamics (Beek, 1989; Schaal, Sternad, & Atkeson, 1996).

These authors found that to be stable, the acceleration of the hands (or feet?) has to be negative at the moment of impact: i.e. . They also found that the standard deviation of the acceleration at impact was proporational to the acceleration, suggesting a dynamic scaling rule. They conclude that this is a means by which to perfom the activity with a minimum of sensory feedback.

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Beek, P. J. and Lewbel, A. (1995), "The science of juggling", Scientific American, Nov 1995, 92-97

Schaal, S., Sternad, D., & Atkeson, C. G. (1996). One-handed juggling: Dynamical approaches to a rhythmic task. Journal of
Motor Behavior, 28(2), 165-183.

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