Nathalie Gal-Petitfaux

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 performance.

Configurations of activity : from the coupling of individual actions to the emergence of collective activity. A study of mathematics teaching situation in primary school

This article presents and uses the notion of configuration of activity, which extends the Norbert Elias’s original concept of social configuration based on the study and analysis of individual and collective activity. Although this concept embraces all types of social activities, in the present study the authors used it to describe and analyse various classroom activities during a primary school mathematics lesson. Individual action is described as being meaningful to the agent, according to semiological theory of course‐of‐action. The configuration of activity in the classroom is described as a collective activity with a global form embedded in a culture and emerging from the dynamics of points of articulation between individual actions. It presents the main characteristics of autonomous systems: (a) the emergence of an order; (b) the individuation of a form; (c) the existence of a unit with borders specified by the process of self‐reproduction; and (d) the system sensibility to perturbation by outside events. Using the concept of the classroom configuration of activity, this study allows for new insights in the emergence of a collaborative activity between teacher and pupils in the classroom.

Evaluation of the Measuring Active Drag system usability: An important step for its integration into training sessions

This paper is the first stage of an iterative process aiming at the (re)design of a training device for swimming. The purpose of this study was to evaluate the usability of the Measuring Active Drag (MAD) system, a technical device for biomechanical evaluation and performance analysis. To do so, this study examines real activity of elite swimmers using this system. It was conducted within an activity-centred approach: the course-of-action technological research programme. Three international male swimmers volunteered to participate in the study. Two types of data were collected: (a) video recordings, and (b) verbalisations during post-protocol interviews. The data were processed in two steps: (a) reconstructing each swimmer’s course of action, and (b) comparing these courses of action. The results are presented in two stages: (a) the concerns and modalities of using, and (b) use sensations. One of the most important results was that these components changed according to the swimmer’s speed when using the MAD system. The discussion is organized in two sections: (a) usability of the MAD system, and (b) design proposals to insert MAD system into training sessions.