Neurobiological degeneracy and affordance perception support functional intra-individual variability of inter-limb coordination during ice climbing

This study investigated the functional intra-individual movement variability of ice climbers differing in skill level to understand how icefall properties were used by participants as affordances to adapt inter-limb coordination patterns during performance. Seven expert climbers and seven beginners were observed as they climbed a 30 m icefall. Movement and positioning of the left and right hand ice tools, crampons and the climber's pelvis over the first 20 m of the climb were recorded and digitized using video footage from a camera (25 Hz) located perpendicular to the plane of the icefall. Inter-limb coordination, frequency and types of action and vertical axis pelvis displacement exhibited by each climber were analysed for the first five minutes of ascent. Participant perception of climbing affordances was assessed through: (i) calculating the ratio between exploratory movements and performed actions, and (ii), identifying, by self-confrontation interviews, the perceptual variables of environmental properties, which were significant to climbers for their actions. Data revealed that experts used a wider range of upper and lower limb coordination patterns, resulting in the emergence of different types of action and fewer exploratory movements, suggesting that effective holes in the icefall provided affordances to regulate performance. In contrast, beginners displayed lower levels of functional intra-individual variability of motor organization, due to repetitive swinging of ice tools and kicking of crampons to achieve and maintain a deep anchorage, suggesting lack of perceptual attunement and calibration to environmental properties to support climbing performanc

Ecological Dynamics: a theoretical framework for understanding sport performance, physical education and physical activity

International audienceThis paper focuses on the role of Ecological Dynamics as a theoretical framework for analysing performance of athletes and sports teams as complex adaptive systems. It combines key concepts from ecological psychology and nonlinear dynamical system theory, seeking to enhance understanding of performance and learning contexts in sport, to aid the acquisition and transfer of adaptive human behaviours. In ecological psychology the continuous regulation of human behaviour is predicated on the role of information that emerges from the individual–environment system to guide activity. The information sources that constrain performance behaviours are affordances, which provide invitations for action offered by each individual's perception of functional relations with a performance environment. This information-based approach has been enhanced with the integration of tools and concepts from nonlinear dynamics to explain how information is cyclically related to the dynamics of a performance environment. Dynamical systems theory addresses the emergence of coordination tendencies that exist between and within components and levels of complex neurobiological systems. Ecological Dynamics identifies key properties of expertise in sport predicated on the performer-environment relationship as the appropriate scale of analysis. This paper introduces the key properties of expert movement systems that include multi-and meta-stability, the functional role of adaptive movement variability, redundancy, degeneracy and the attunement to affordances. Additionally, we discuss the concept of representative design, which in an ecological dynamics framework underpins the organisation of experimental and learning environments so that observations and acquired skills can be linked to emergent functional behaviours in a specific performance context