Prediction of ball direction in soccer penalty through kinematic analysis of the kicker.

The penalty kick is a crucial opportunity to score and determine the outcome of a soccer match or championship. Anticipating the direction of the ball is key for goalkeepers to enhance their defensive capabilities, considering the ball's swift travel time. However, it remains unclear which kinematic cues from the kicker can predict the ball's direction. This study aimed to identify the variables that predict the ball's direction during a soccer penalty kick. Twenty U19 soccer players executed penalty kicks towards four targets positioned in the goal, while kinematic analysis was conducted using a 3D motion analysis system. Logistic regression analysis revealed that trunk rotation in the transverse plane (towards the goal - left; or slightly to the right - right) served as the primary predictor of the ball's horizontal direction at 250 and 150 ms before the kicking foot made contact. Additionally, the height of the kicking foot in the sagittal plane solely predicted the vertical direction at the moment of contact. This information, encompassing trunk rotation and kicking foot height, can be employed in perceptual training to enhance decision-making and the implementation of feints during penalty kicks.

Effects of Transcranial Direct Current Stimulation on Muscle Fatigue in Recreational Runners: Randomized, Sham-Controlled, Triple-Blind, Crossover Study-Protocol Study.

OBJECTIVES: The aim of this study is to evaluate the effects of transcranial direct current stimulation (tDCS) on central and peripheral fatigue in recreational runners. DESIGN: This is a clinical randomized, sham-controlled, triple-blind, crossover study. Twenty adult runners will be randomized on the first day of the intervention to receive active or sham tDCS before fatigue protocol. After 1 wk, the participants will receive the opposite therapy to the one that they received on the first day. The tDCS, 2 mA, will be applied for 20 mins over the motor cortex. The fatigue protocol will be performed after tDCS, in which the participant should perform concentric knee flexion/extension contractions until reaching three contractions at only 50% of maximum voluntary contraction. Central fatigue will be evaluated with the motor evoked potential of the quadriceps muscle; peripheral fatigue with the peak torque (N.m) using an isokinetic dynamometer; the electrical activity of the quadriceps muscle using surface electromyography (Hz); blood lactate level (mmol/L); and the subjective perception of effort (Borg scale). All evaluations will be repeated before and after the interventions. CONCLUSION: This study will evaluate the effect of tDCS on fatigue in runners, possibly determining an application protocol for this population.

Automatic postural responses are scaled from the association between online feedback and feedforward control.

Generation of automatic postural responses (APRs) scaled to magnitude of unanticipated postural perturbations is required to recover upright body stability. In the current experiment, we aimed to evaluate the effect of previous postural perturbations on APR scaling under conditions in which the current perturbation is equal to or different from the previous perturbation load inducing unanticipated forward body sway. We hypothesized that the APR is scaled from the association of the current perturbation magnitude and postural responses to preceding perturbations. Evaluation was made by comparing postural responses in the contexts of progressive increasing versus decreasing magnitudes of perturbation loads. Perturbation was applied by unanticipatedly releasing a cable pulling the body backwards, with loads corresponding to 6%, 8% and 10% of body mass. We found that the increasing as compared to the decreasing load sequence led to lower values of (a) displacement and (b) velocity of center of pressure, and of activation rate of the muscle gastrocnemius medialis across loads. Muscular activation onset latency decreased as a function increasing loads, but no significant effects of load sequence were found. These results lead to the conclusion that APRs to unanticipated perturbations are scaled from the association of somatosensory feedback signaling balance instability with feedforward control from postural responses to previous perturbations.

Short-term resistance training with instability reduces impairment in V wave and H reflex in individuals with Parkinson's disease.

This study had two objectives: 1) to compare the effects of 3 wk of resistance training (RT) and resistance training with instability (RTI) on evoked reflex responses at rest and during maximal voluntary isometric contraction (MVIC) of individuals with Parkinson's disease (PD) and 2) to determine the effectiveness of RT and RTI in moving values of evoked reflex responses of individuals with PD toward values of age-matched healthy control subjects (HCs) (z-score analysis). Ten individuals in the RT group and 10 in the RTI group performed resistance exercises twice a week for 3 wk, but only the RTI group included unstable devices. The HC group (n = 10) were assessed at pretest only. Evoked reflex responses at rest (H reflex and M wave) and during MVIC [supramaximal M-wave amplitude (Msup) and supramaximal V-wave amplitude (Vsup)] of the plantar flexors were assessed before and after the experimental protocol. From pretraining to posttraining, only RTI increased ratio of maximal H-reflex amplitude to maximal M-wave amplitude at rest (Hmax/Mmax), Msup, Vsup/Msup, and peak torque of the plantar flexors (P < 0.05). At posttraining, RTI was more effective than RT in increasing resting Hmax and Vsup and in moving these values to those observed in HCs (P < 0.05). We conclude that short-term RTI is more effective than short-term RT in modulating H-reflex excitability and in increasing efferent neural drive, approaching average values of HCs. Thus short-term RTI may cause positive changes at the spinal and supraspinal levels in individuals with PD. NEW & NOTEWORTHY Maximal H-reflex amplitude (Hmax) at rest and efferent neural drive [i.e., supramaximal V-wave amplitude (Vsup)] to skeletal muscles during maximal contraction are impaired in individuals with Parkinson's disease. Short-term resistance training with instability was more effective than short-term resistance training alone in increasing Hmax and Vsup of individuals with Parkinson's disease, reaching the average values of healthy control subjects.

Reflexões sobre a interação cérebro-máquina: muito além dos neurônios / Reflections on the interaction brain-machine: much beyond the neurons

Este artigo visa a problematização de questões como: há diferença entre o "cérebro" e uma máquina? É possível responder o que é uma decisão tipicamente de um "cérebro" ou de um computador? O que nos separa das máquinas? São trazidos ainda, à tona, tópicos sobre o pensamento e a emoção; quais suas características, a existência de uma localização para estes e se existe a possibilidade do mesmo poder ser replicado por máquinas. Adota-se como recorte dos pressupostos aqui enunciados algumas abordagens: evolutiva, biológica, de processamento de informação e de inteligência artificial. © Ciências & Cognição 2005; Vol. 06: 133-141(AU)

This article aims to focus questions as: has difference between the "brain" and a machine? It is possible to answer what it is a decision typically of a "brain" or a computer? What separates us of the machines? It is brought still topics about thought and emotion, like which its characteristics, the existence of a localization for these, and if it is possible that same one exists to be able to be talked back by machines. Therefore, It is adopted some approaches to this article aims at this problem from some approaches, namely: evolutionary, biological, of information processing and of artificial intelligence. © Ciências & Cognição 2005; Vol. 06: 133-141.(AU)