The anatomy of antagonistic coregulation: Emergent coordination, path dependency, and the interplay of biomechanic parameters in Aikido.

Using a video-supported cognitive ethnographic and phenomenological approach, we address the interactively generated dynamic of bouts in Aikido. This "soft" martial art enables a defender to blend with and then redirect an attacker's aggressive energy so as to break his balance, while preserving an ethos of non-violence, mutuality, and respect. Our analysis explores the skills used to minutely adapt to the opponent, the causal-temporal structure of Aikido, notably the cumulative effect build-up and main decision points in a bout, as well as the perceptual cues from inter-body geometry, timing, and force dynamics that inform decisions. We then contrast different interaction scenarios by focusing on micro-events that shape defensive preferences. For a successful defense, technical modulations or even the preferred technique itself can be selected as the interaction unfolds ("decision-making-in-action"). For a closer look, we analyze the interplay of multiple parameters: flexibility of intention (i.e. early deciding vs. keeping options openlonger), technique (i.e. type of lever or throw), initial body symmetry, step combinations, spacing and timing relative to the attacker, degree of force, as well as possible skill differentials. We describe complex interdependencies between these parameters, which can be balanced in various ways as agents respond to the interaction dynamic.