Electromyographic study of the arms in competitive karting senior category drivers / Estudio electromiográfico de los brazos en pilotos senior de karting de competición

The main goal of this cross-sectional study was to assess the muscular activity of the upper limbs in competitive kart drivers while driving in a closed karting circuit, using surface electromyography (EMGS). The most significant muscles of the upper limbs while driving were evaluated in thirteen drivers. Linear mixed models adjusted to a gamma distribution were used to evaluate differences in muscle activity based on the arm, number of laps, track characteristics, and kart type (with/without gears). Significant differences were found between muscle activity according to the type of kart (p <0.0001). Although changes were observed in the mean EMGS values, there were no significant differences between the laps of the circuit or the dominant arm. However, the results showed that there was a significant interaction between the type of kart and the dominant arm (p = 0.021). Muscle activity increased more significantly in the curves traced towards the dominant arms of the drivers (AU)

El objetivo del estudio transversal fue analizar la actividad muscular de las extremidades superiores en pilotos senior de karting de competición, mediante electromiografía de superficie (EMGS). Se evaluaron los músculos más significativos de las extremidades superiores durante la conducción en trece conductores. Se utilizaron modelos lineales mixtos ajustados a una distribución gamma para evaluar diferencias de actividad muscular en base al brazo, número de vueltas, características del trazado, y tipo de kart (con/sin marchas). Se encontraron diferencias significativas entre la actividad muscular según el tipo de kart (p<0,0001). Aunque se observaron cambios en los valores medios de EMGS, no hubo diferencias significativas entre las vueltas del circuito o el brazo dominante. Sin embargo, los resultados mostraron que hubo una interacción significativa entre el tipo de kart y el brazo dominante (p=0,021). La actividad muscular aumentó de manera más significativa en las curvas trazadas hacia el brazo dominante de los conductores (AU)

Pitch perception deficits in nonverbal learning disability.

The nonverbal learning disability (NLD) is a neurological dysfunction that affects cognitive functions predominantly related to the right hemisphere such as spatial and abstract reasoning. Previous evidence in healthy adults suggests that acoustic pitch (i.e., the relative difference in frequency between sounds) is, under certain conditions, encoded in specific areas of the right hemisphere that also encode the spatial elevation of external objects (e.g., high vs. low position). Taking this evidence into account, we explored the perception of pitch in preadolescents and adolescents with NLD and in a group of healthy participants matched by age, gender, musical knowledge and handedness. Participants performed four speeded tests: a stimulus detection test and three perceptual categorization tests based on colour, spatial position and pitch. Results revealed that both groups were equally fast at detecting visual targets and categorizing visual stimuli according to their colour. In contrast, the NLD group showed slower responses than the control group when categorizing space (direction of a visual object) and pitch (direction of a change in sound frequency). This pattern of results suggests the presence of a subtle deficit at judging pitch in NLD along with the traditionally-described difficulties in spatial processing.