Expert decision-making can be directly assessed, if sport action is understood as an expression of embedded and embodied cognition. Here, we discuss evidence for this claim, starting with a critical review of research literature on the perceptual-cognitive basis for expertise. In reviewing how performance and underlying processes are conceived and captured in extant sport psychology, we evaluate arguments in favour of a key role for actions in decision-making, situated in a performance environment. Key assumptions of an ecological dynamics perspective are also presented, highlighting how behaviours emerge from the continuous interactions in the performer-environment system. Perception is of affordances; and action, as an expression of cognition, is the realisation of an affordance and emerges under constraints. We also discuss the role of knowledge and consciousness in decision-making behaviour. Finally, we elaborate on the specificities of investigating and understanding decision-making in sport. Specifically, decision-making concerns the choice of action modes when perceiving an affordance during a course of action, as well as the selection of a particular affordance, amongst many that exist in a landscape in a sport performance environment. We conclude by pointing to some applications for the practice of sport psychology and coaching and identifying avenues for future research.

Background: There are deeply relevant questions concerning how to integrate and organise various nonlinear pedagogical strategies and methods in order to structure training in the professional development of Physical Education (PE) teachers and sport coaches. To promote the emergence and development of innovative and adaptive performance behaviours in sport, nonlinear pedagogy advocates the methodology of constraints manipulation to facilitate learning. Sport pedagogues have to manage and apply different constraint manipulations at varying times in practice contexts, that is, while planning before/following a learning session (i.e. designing the micro-structure of practice) and in interactions during the session. In nonlinear pedagogy, the design of practice micro-structure is predicated on the continuous, intertwined relationships between decision-making, action, perception and cognition in sport performance and learning contexts. Purpose: Here, we present an analysis of the activities that pedagogues engage in to facilitate learning and performance in sport (i.e. the micro-structure of practice) during practical interventions in sport and exercise contexts, based on the use of a Constraints-led approach by PE teachers and coaches. Method: Based on data from illustrative studies on performance analysis and constraints manipulation, we exemplify some of the main principles and assumptions of nonlinear pedagogy. This synthesis, framed in a nonlinear pedagogy, aims to reveal how adopting a constraint led approach can straightforwardly enhance learning designs of sport practitioners. Conclusions: This article shares insights from a nonlinear pedagogy that can frame the micro-structure of practice during interventions, compared to utilization of traditional pedagogical practices. It is proposed that PE teachers and coaches are designers of learning environments and that both learning and performance improvement are seen as emerging from the interaction of key constraints (related to task, learner and environment).

This study aimed to quantify and compare the upper limb angular kinematics and its contributions to the racket head speed between the cross-court (CC) and inside-out (IO) attacking tennis forehand of elite tennis players in a competitive environment. A new approach was used to study the forehand drive with mini-inertial sensors of motion capture to record the kinematic data. Six strokes in each direction per participant (72 shots in total) were chosen for analysis. Upper limb kinematics were calculated in the Visual 3D platform (Visual 3D Professional V5.01.21, C-motion, Germantown, MD, USA). The method used to calculate the upper limb’s contributions was performed with MATLAB software and used the segment’s (upper arm, forearm and hand) angular velocities and their respective displacement vectors obtained through the inertial sensors. Upper limb kinematics demonstrated a higher shoulder rotation in the IO direction with significant differences at the end of the backswing, which could be a key factor in distinguishing the two directions of the shot. Results also demonstrated that the horizontal flexion of the upper arm (around the shoulder joint) was primarily responsible for the racket velocity in the anteroposterior direction (48.1% CC and 45.2% IO), followed by the extension of the forearm (around the elbow joint) (17.3% CC and 20.9% IO) and the internal rotation of the upper arm (around the shoulder joint) (15.6% CC and 14.2% IO). No significant differences were shown in the contributions of upper limbs to the racket head velocity between the two directions of the shot. Tennis coaches and players should develop a specific training programme to perform higher angular velocities in these specific joint rotations.

This study analysed how the relative positioning of players on court influenced patterns of interpersonal coordination in baseline rallies in tennis. We developed a model (PA index) that assigns a weight to the position of each player on court and determines a positional advantage, based on the relative proportionality between the lateral and longitudinal displacement values during rallies. To test the model, data from 27 randomly-selected baseline rallies from three ATP World Tour matches (professional tennis players' tournaments organized by Association of Tennis Professionals) on clay were analysed. Results revealed that the PA index of players on court described their interpersonal coordination dynamics during baseline rallies. It also identified the emergence of rally breaks in the interpersonal coordination patterns of competing dyads that led to a point being scored. Data suggest that positional advantage data may assist coaches in the design of training tasks to enhance players' court coverage and performance during competitive interactions, acting as a valuable tool for performance analysis in tennis.

In tennis, the relative positioning of players on court constrains their opportunities to perform successful actions. In this study we proposed and validated an empirical function that captures the spatial-temporal relationship between tennis players during competitive performance. This parameter, termed goal-directed displacement index (GDD Index), is defined over time by the product of both players' distances to the central line of the court and to the centre of the net. Results showed that the GDD index successfully described tennis players' patterns of interaction, as well as identified breaks in patterns of play during competitive performance, due to changes in relative positioning on court. Our analysis revealed two different patterns of interpersonal interactions, cross and down-the-line rallies, and two ways for a break to emerge in game dynamics, parallel variation (transition from a cross court rally to a down-the-line rally) and angle opening (lateral displacement). Data suggest that the elaboration of specific individual profiles of performance for different players, using the GDD index, could improve performance analysis in tennis.