title: Affordance-controlled bifurcations of action patterns in martial arts.
abstract: Effects of participant-target distance and perceived handstriking efficiency on emergent behavior in the martial art of boxing were investigated, revealing affordance-controlled nonlinear dynamical effects (i.e. bifurcations) within the participant--target system. Results established the existence of critical values of scaled distances for emergence of first time excitations and annihilations of a diverse range of boxing actions i.e. on the appearance and dissolution of jabs, hooks and uppercuts. Reasons for the action diversity were twofold: (a) topological discontinuous changes (bifurcations) in the number of possible handstrikes, i.e. motor solutions to the hitting task; (b) fine modification of probabilities of emergence of striking patterns. Exploitation of a 'strikeability' affordance available in scaled distance-to-target information by boxers led to a diversity of emergent actions through a cascade of bifurcations in the task perceptual-motor work space. Data suggested that perceived efficiency (E) of an action changed as a function of scaled distance (D) and was correlated with the probability of occurrence of action patterns (P), exhibiting the following dependence P = P(E(D)). The implication is that probability of occurrence (P) depends on efficiency (E), which in turn depends on scaled distance (D) to the target. Accordingly, scaled distance-dependent perceived efficiency seems a viable candidate for a contextual (control) parameter to describe the nonlinear dynamics of striking actions in boxing.
authors.affiliation: Faculty of Physical Culture, University of St. Cyril and Methodius Zeleznicka BB, Skopje, 1000, Republic of Macedonia. robert_hristovski@yahoo.com
authors.forename: Robert
authors.initials: R
authors.lastname: Hristovski
authors.forename: Keith
authors.initials: K
authors.lastname: Davids
authors.forename: Duarte
authors.initials: D
authors.lastname: Araújo
mesh_terms: D000328:Adult; D003627:Data Interpretation, Statistical; D006801:Humans; D008297:Male; D016139:Martial Arts / Q000706:statistics & numerical data*; D009068:Movement; D011597:Psychomotor Performance; D013037:Spatial Behavior