Search

One of the main theories in ecological psychology is the theory of affordances. Affordances are opportunities for action which are provided by the environment in which the action takes place and are action specific. So affordances describe how the environment allows, supports and constrains an action. The idea of studying the affordances can also be applied to sport, in this case to putting in golf, to gain insight into how performance is influenced by the sport specific environment. During tournaments, discrete experiences of players while performing a putt were collected for several rounds at one green. Using the ISOPAR method (Stöckl et al., 2011) all the single experiences of one round of the different players were transformed into a continuous average experience of the field across the whole green. Based on ISOPAR maps we can visualize the affordances and constraints which influenced the field's play. According to the number and the arrangement of the iso-lines on the ISOPAR maps we can identify areas on the green where the play of the field was constrained heavily by gradients on the green's surface and/or distance to the cup. [ABSTRACT FROM AUTHOR]

Spectral parameters of surface electromyography (EMG) are used to assess intramuscular coordination in terms of fatigue and motor unit recruitment. The aim of the present study was to examine changes in performance and EMG spectral parameters of the propulsive muscles during a swim bench exercise in swimmers to determine the intra-individual effects of different training periods in the normal training process. Ten swimmers of different ages and standards were investigated in a longitudinal study. Electromyograms of the relevant muscles (triceps longum, triceps lateralis, and latissimus dorsi) were recorded during the tests, and spectral parameters calculated using time-variant spectral analysis. In the elite swimmers, we observed variation in performance throughout the training season with respect to training load, whereas for the junior swimmers there was a trend to improve performances irrespective of training load. Correlations with performance were observed for the median frequencies of the triceps longus for the elite athletes. Performances and frequencies were increased in the taper period, whereas they were reduced after periods of high training loads. For the junior swimmers, no such correlations were observed. Based on our results, spectral parameters could provide information about the fatigue of the neuromuscular system of elite swimmers during periods of high training loads and enhanced intramuscular coordination in the taper period before competition. [ABSTRACT FROM AUTHOR]

The present study investigated whether there is an anticipatory postural adjustment (APA) prior to the onset of predictable perturbation generated by a releasing in the archery performance task. Eighteen volunteers were divided into two groups (expert vs. novice) depending on skill levels. Participants stood on a force plate holding a bow with a laser pointer and took a full drawing motion aiming the laser pointer to the center of target, placed 10 m away from the force plate, then released motion was performed based on the individual's preferred timing. Motion capture system measured the bow motion in 3D, two force plates estimated center of pressure (COP) displacements, and electromyographic (EMG) recorded eight lower limb muscles during the anticipatory and compensatory phases of postural control. The results revealed that, compared to the novice group, (1) the expert group showed smaller variability of bow motion, (2) the APA patterns of the COP and muscle activities before the onset of perturbation (releasing), and (3) shorter time interval between the perturbation onset and the COP peak displacement. The findings suggest that a long‐term practice results in the experts could be adopted to use APA generating mechanical benefit to compensate for predictable perturbation. This would be able to lead to a more stable subsequent postural control to realize the task goal. Highlights: Skill level generates anticipatory postural adjustment (APA) to compensate for a predictable perturbation in the archery performance.The expert showed smaller bow motions in the vertical direction from APA to CPA2 phase.The expert showed the center of pressure (COP) and electromyographic (EMG) activities before the perturbation onset.The expert showed a shorter time interval between the perturbation onset and the COP peak displacement. [ABSTRACT FROM AUTHOR]