This study investigated the effects of a 24-week combined training program (CTP) based on strength exercises and cognitive–motor tasks performed concurrently in participants with multiple sclerosis. A randomized, controlled intervention study was carried out. In total, 31 subjects with a confirmed diagnosis of multiple sclerosis (14 men and 17 women) were stratified and randomized into an intervention group (17 subjects) and a control group (14 subjects). The intervention group completed three weekly training sessions for 24 weeks, while the control group pursued their normal daily activities. In this program, cognitive–motor tasks were completed at once (dual tasking). A 3D photogrammetry connected to a selective attention system designed for dual tasking while walking was used. Ground reaction forces were measured using two force plates, one for sit-to-stand testing, while the other was used for static force measurement. Postural equilibrium was examined using a stabilometric plate based for Romberg test assessment. The 24-week training program for multiple sclerosis patients improved their static peak force by 11% (p < 0 .05), their rate of force development by 36% (p < 0.05), and their balance (p < 0.05). Performance in daily activities such as walking or sitting-to-standing improved significantly in multiple sclerosis participants. CTP training was effective in reducing the dual-task costs of step length (48%) and walking velocity (54%), as compared to a matched control group.

The aim of this study was to analyse the effect of stimulus change timing on reaction response time parameters, horizontal velocity of the centre of mass (CM) and precision during offensive actions in fencing. Twelve fencers from the Spanish National Foil Team were included in the study. Two 500 Hz force plates were used to register the horizontal component of the reaction force while a 3D video camera set at 250 Hz recorded the spatial position of 11 body markers and a projector connected to a programmed stopwatch projected a moving target (stimulus) on a screen. When the circle (target) appeared in the centre of the plastron, fencers had to execute a step-forward-lunge as fast as possible, trying to touch the circle with the tip of the foil. During the lunge, the position of the target could randomly shift or not to three different positions. The stimulus change was performed randomly at four different times with a progressive delay. The results show that target changes did not have any effect when they occurred at the beginning of the movement sequence. However, when the target change was delayed, reaction and movement times increased and the technical execution of the lunge changed, leading to more errors.

The objectives of this study were to investigate the effect that the presence of two stimuli that require two different responses (dual-attention) has both, on offensive reaction-response time to a light stimulus, and on defensive response time when the stimulus is a real fencing attack. Twenty-five elite fencers and a fencing master were included in the study. The equipment included four force plates adapted to a scaffold that served as a fencing piste. Two force plates were placed, at the start position, under the fencer's feet and another two plates were placed under the master's feet. The results demonstrate that choice reaction time to visual stimuli increases in dual-task conditions with respect to simple reaction time, whereas the mean horizontal force tends to decrease in dual-task. However, when the stimulus was an opponent's movement, dual-task conditions did not have any effect on the time required to initiate a defensive action. The changes in reaction time when real movements were used as stimuli challenge the validity of the reaction time to visual stimuli paradigm as a predictor of performance in fencing. Also, the results obtained demonstrate that perceptual and attentional processes play a major role in fencer performance in real competition.

Purpose The aim of the study was to assess dual-task cost to spatio-temporal gait parameters in people with multiple sclerosis and a matched control group. Method The multiple sclerosis group was composed of 17 participants with a diagnosis of multiple sclerosis and an Expanded Disability Status Scale score of less than 6. A total of 17 healthy participants were allocated to the control group by stratification. Controls were matched on the basis of age, sex, sociocultural habits, and body structure. Dual-task cost was determined by within-group repeated-measures analysis of variance. Participants were instructed to ambulate under normal conditions and perform a discrimination and decision-making task concurrently. Then, between-group analysis of variance was used to assess differences in mean dual-task cost between groups and determine dual-task cost differential. Testing was performed using three-dimensional photogrammetry and an electronic walkway. Results Based on dual-task cost differential, gait cycle time increase (−5.8%) and gait speed decrease (6.3%) because of multiple sclerosis–induced impairment. Conclusions During single- and dual-task conditions, gait speed was lower in multiple sclerosis participants, because of a shorter step length and increased swing time. Increased gait time might be the result of compensatory mechanisms adopted to maintain stability while walking specially during the double-support phases.

The two-fold purpose of this study was to analyze the time required by a fencer to initiate a defensive action in response to a direct attack, which involves identifying when the defending fencer detects the just-noticeable difference, and, secondly, to assess the effect that an attacker's rapid armed hand movement (feint attack) has on the time required to initiate a defensive move. Twenty-four elite fencers and a fencing master were included in the study. Four adapted force plates were installed on a scaffold used as a fencing piste. A 3D video analysis system recorded the location of 2 markers installed on the fencing master's shoulder and sword. The results confirm that the defending fencer has a mean movement time of 0.353 ± 0.028 s to perform the defensive action, which provides an advantage over the attacking fencer. The velocity of movement in the peripheral visual field has no influence on the time required by elite fencers to initiate a defensive action. This confirms the crucial role that response inhibition processes play when nonrelevant actions are perceived. Kinematic analysis of markers suggests that the eye movements of elite fencers are not the only source of information used while observing an attack.

Applying the Go/No-Go paradigm to fencing, we investigated the relationship between the moment at which the No-Go signal appeared after a movement had been initiated and the time required by fencers to suppress the motor execution of a step-lunge. Secondarily, we determined a time threshold from which movement inhibition results in an error. The No-Go stimulus was represented by a real attack movement. 18 elite fencers and a fencing master were included in the study. Four force plates measured the horizontal components of the fencer's and master's reaction forces, which were used to calculate the time components of the attack and the response inhibition process. Also, the velocity and displacement of the master's and fencer's respective centres of mass were estimated using inverse dynamics. In all cases, cognitive inhibition processes were completed after the onset of movement. Movement time was calculated using four time components (muscle activation, muscle deactivation, transition and braking time). The results obtained revealed that cognitive processes were not significantly affected by the timing of the appearance of the No-Go signal. In contrast, movement time and its time components tended to decrease when the time delay between the No-Go stimulus and the onset of the fencer's movement increased. In conclusion, any attempt to withhold an attack movement when it has already started leads to an error that increases the risk of being hit by the opponent, especially when attack is inhibited within 150 ms after the movement has started.

This study aimed to determine the effect of increasing the mass of the official handball ball on horizontal force, velocity, and power outputs. Twelve male handball players from the Spanish Asobal Handball League performed overarm throws with four balls: official (0.460 kg), Δ15% (0.529 kg), Δ45% (0.667 kg), and Δ75% (0.805 kg). The throws were filmed with two cameras temporally synchronized at 250 Hz and digitized at 125 Hz, making possible to obtain the spatial coordinates of a model composed by six body markers plus the geometric center of the ball. Incrementing the mass of the ball produced a progressive reduction in velocity and increase in force ( p < 0.001). The power tended to increase with the increment of the mass, but significant differences were only reached for the heaviest condition (Δ75%) and it was linked to changes in the application of force with respect to time. The maximum values of force, velocity and power with respect to the release of the ball, were delayed with the increment of the mass ( p < 0.001). These results evidence that the power applied to the ball can only be increased when heavy balls, which modify the structure of the throw, are used.

El objetivo principal del estudio fue definir las características del esfuerzo desde el punto de vista de la carga externa en jugadoras de baloncesto de alto nivel en dos competiciones: Euroliga femenina y Campeonato del Mundo. Para ello, se analizaron ocho partidos de las fases finales de ambas competiciones. Se llevó a cabo un análisis detallado de los patrones de movimiento de 96 jugadoras pertenecientes a ocho selecciones nacionales y a cinco equipos profesionales. Se utilizaron ocho categorías de actividad a la hora de clasificar las acciones y los desplazamientos en los partidos: parado/caminando, trote, carrera, sprint, salto y shuffle baja, media y alta intensidad. Se calculó el tiempo total en cancha, el tiempo real y el porcentaje de tiempo real respecto del tiempo total. Por otro lado se analizó la frecuencia y la duración media de cada actividad así como el porcentaje de tiempo real empleado en cada una de ellas. Los resultados obtenidos confirman la naturaleza híbrida del esfuerzo, en el que se alternan fases aeróbicas y anaeróbicas, predominando las primeras sobre las segundas. Se observa que los esfuerzos anaeróbicos son los que marcan la diferencia entre niveles competitivos y entre posiciones habituales de juego. Asimismo se observa que sólo las jugadoras en la posición de base presentan un perfil específico de esfuerzo que las diferencia de aleros y pívots.