BIOMECHANICAL INVESTIGATION OF THE KIZAMI TSUKI IN KARATE ATHLETES

The purpose of this study was to investigate the kinematics and kinetics characteristics of kizami tsuki karate punch technique. Punching actions represent the most frequently performed attacking techniques in karate combat competitions (75% of total actions, kizami tsuki being the most common). Six athletes were asked to perform three kizami tsuki against a hand-held target at their maximal speed. Punch kinematics and kinetics were recorded by means of stereophotogrammetry and forceplates. Power, lower and upper limb kinematics and their coordinative pattern during the punching actions were assessed to characterize the technique. A multiple linear regression model was devised to correlate punching kinematics and kinetic variables with maximal wrist velocity, considered as performance measure. Maximal net power, transformation time, average continuous relative phase between knee and elbow flexion-extension, and elbow peak flexion were significative predictors of wrist velocity (R2 = 0.84), indicating them as key factors to a proficient-performance of the kizami tsuki

Motor Competence in Individuals with Down Syndrome: Is an Improvement Still Possible in Adulthood?

In children, motor competence (MC) and the amount of physical activity are tightly interconnected. In adults with Down syndrome (DS), MC has been poorly addressed, resulting in a limited understanding of the possibility to improve MC over time. Here, we aim to: (1) investigate MC in adults with DS by comparing them with a group of typically developed peers and (2) verify the effect of an adapted karate program on MC. Adults with DS (DSG; n = 57) and typically developed adults (TDG; n = 21) performed the Test of Gross Motor Development version 3 (TGMD-3). The total TGMD-3 score (TOTTGMD-3), the locomotor (LOCTGMD-3), and object control (OBJTGMD-3) scores were computed. After a 40 week adapted karate program, DSG (n = 37) underwent the post-training TGMD-3 assessment. Compared to TDG, DSG showed lower TOTTGMD-3 (DSG: 45.5 ± 17.3; TDG: 77.3 ± 9.5), LOCTGMD-3 (DSG: 22.2 ± 10.0; TDG: 36.2 ± 7.6) and OBJTGMD-3 (DSG: 23.3 ± 10.9; TDG: 41.1 ± 5.6). After the training, TOTTGMD-3, LOCTGMD-3 and OBJTGMD-3 increased by 35.6%, 30.0% and 40.7%, respectively. Our results suggest that MC acquisition does not evolve into a mature form in adulthood in individuals with DS. Moreover, a brief exposure to an adapted karate program induces an increase in motor competence in DS, even in adulthood

Electrophysiological Evidence of Anticipatory Cognitive Control in the Stroop Task

The Stroop task has been largely used to explore the ability to inhibit the automatic process of reading when reporting the ink color of incongruent color-words. Given the extensive literature regarding the processes involved in task performance, here we aimed at exploring the anticipatory brain activities during the Stroop task using the event-related potential (ERP) method. To accomplish this, eighteen participants performed two different blocks where neutral words were intermixed with congruent and incongruent words, respectively. Results revealed consistent pre-stimulus activity over the frontal, premotor and parietal brain areas. The premotor and the parietal activities were also modulated by the Stroop effect, being more enhanced in the incongruent than in the congruent blocks. Present findings add on the current literature pointing at an unexplored locus of anticipatory cognitive control during task preparation, thus offering a new way to investigate top-down preparatory processes of performance control in the Stroop task

Does sport type matter? The effect of sport discipline on cognitive control strategies in preadolescents

This study aimed to test the effects of specific sport practices on cognitive sensory-motor performance and underlying brain functions in children. Behavioral performance and event-related potentials (ERP) were investigated during a cognitive visuomotor task in 64 preadolescent children practicing racket (Rack) sports, martial arts (Mart), indoor climbing (Clim), or not practicing any sport (controls, Cont). At the behavioral level, response speed and accuracy were studied. At the electrophysiological level, motor, cognitive and sensory-attentional readiness, and post-perceptual attentional functions were investigated. Behavioral results showed that Mart players had the fastest response time (RT). Rack players had the most consistent RT and committed the lowest omission errors. Clim athletes were the most accurate in terms of false alarms. ERP results showed that motor readiness was largest in Mart players. The Rack group had the largest cognitive preparation and the Clim one had the largest sensory-attentional readiness activity. Rack and Mart players had the largest activity associated with post-perceptual attentional processing. This result shows that practicing specific sports may allow differential benefits on cognitive processing. Racket sports seem to stimulate action speed consistency and improve accuracy for omissions, increasing cognitive preparation, and post-perceptual attentional processing. Mart practice may allow a more speed-oriented response behavior, probably due to large motor preparation and allocation of post-perceptual attentional resources, but only when response execution is required. Indoor climbing may favor response accuracy reducing unwanted responses as indexed by an increased sensory-attentional readiness. Overall, all the considered sports disciplines may improve cognitive processing, but each one is associated with different benefits on cognitive performance by possibly stimulating separate brain processing. This kind of information could be crucial to select the more appropriate sport depending on individual demands

Acute Effects of Whole-Body Vibration on Quadriceps Isometric Muscular Endurance in Middle-Aged Adults: A Pilot Study

This study analysed the acute effects of whole-body vibration (WBV) on quadriceps isometric muscular endurance. Fifteen healthy middle-aged males performed an endurance isometric strength test after three different warm-up conditions: static half squat plus WBV (HSV), static half squat without WBV (HS), and control condition (CC). The endurance isometric strength test consisted of 10 maximal isometric contractions held for 4 s and interspersed by 2 s of rest between each repetition. Rate of Perceived Exertion (RPE) was assessed after warm-up (RPE1) and at the end of the testing session (RPE2). During each testing session, participant’s heart rate (HR) was continuously recorded. For each trial, the mean force across the 10 repetitions and fatigue index were evaluated. Mean force was significantly higher (p 1 and RPE2 were significantly lower (p p p > 0.05) or in HR during the endurance protocol. Performing half-squat with or without vibration stimuli does not increase isometric muscular endurance and does not influence fatigue index

Electrophysiological evidence of sustained spatial attention effects over anterior cortex: Possible contribution of the anterior insula

Spatial attention can improve performance in terms of speed and accuracy; this advantage may be mediated by brain processes at both poststimulus (reactive) and prestimulus (proactive) stages. Here, we studied how visuospatial attention affects both proactive and reactive brain functions using event-related potentials (ERPs). At reactive stage, effects of attention on parietal-occipital components are well documented; little data are available on anterior components. Seventeen participants performed simple and discriminative response tasks, while voluntarily and steadily attending either the left or right visual hemifield throughout one block. Response speed was faster for the attended side. At ERP level, attending to one hemifield did not produce lateralization of proactive components—that is, the BP and the pN. As for poststimulus components, we confirmed the well-known amplitude effects on the P1, N1, and P3. More interesting are results for the prefrontal components previously neglected in tasks modulating spatial attention. Previous studies suggest that these components reflect perceptual and sensory-motor awareness (pN1 and pP1 components), and stimulus-response mapping (pP2 component) associated to anterior insular activity. Spatial attention enhanced the pN1 and the pP1 amplitude but had no effect on the pP2. Overall, results extend knowledge on spatial attention, showing that sustained spatial attention affects the activity of anterior areas, such as the anterior insula, in addition to the known influence on occipital-parietal areas. Top-down spatial attention is likely mediated by increased sensory and sensory-motor awareness for attended events; this effect is evident in reactive, not proactive, brain activity