Coordination modes in the multisegmental dynamics of hula hooping

Biological Cybernetics
March 2004, Volume 90, Issue 3, pp 176-190
Cover Date 2004-03-01
DOI 10.1007/s00422-003-0460-4

Ramesh Balasubramaniam (1,2), M.T. Turvey (2,3)

1) Sensory Motor Neuroscience Group, Behavioural Brain Sciences Centre, School of Psychology, University of Birmingham, Edgbaston, B15 2TT, UK
2) Center for the Ecological Study of Perception and Action, U-20 University of Connecticut, 406 Babbidge Road, Storrs, CT 06269, USA
3) Haskins Laboratories, 270 Crown Street, New Haven, CT 06511, USA

Abstract

In hula hooping, organized motions of the body keep the hoop in stable oscillatory motion parallel to the ground. We examined the hypothesis that the multiple degrees of freedom (DF) of the lower limbs in producing the oscillations are resolved into a few control DF. The Karhunen-Loève decomposition was applied to the kinematics of the lower limbs in three experiments in which oscillation amplitude and frequency were manipulated. Kinematic variance was accommodated by two modes whose relative contributions varied with task parameters. Complementary analyses of interjoint Hilbert relative phase suggested a lower-limb organization into a vertical suspension mode and an oscillatory fore-aft mode. These modes might stabilize the hoop’s angular momentum by controlling, respectively, its vertical and horizontal components.

http://link.springer.com/article/10.1007%2Fs00422-003-0460-4