Wheelchair fencing is a medium-distance combat sport in which the wheelchair is fixed to the floor. This requires a maximum concentration and gestational speed. Refined techniques and fatigue tolerance are essential to achieve competitive results. Aim: The main objective of this study was to measure the speed and muscular participation of a direct attack gesture with and without fatigue in a sample of elite wheelchair fencers. Methods: The maximal isometric force, gestural speed, and resistance to gestural velocity were estimated in 10 elite performed direct fencers. Results: The results revealed that sitting height and wingspan were important factors in achieving the highest speed, especially in women (r = 0.9; p = 0.07). Other factors, such as the elbow angle where the closed position was better, affected muscle contraction in both categories of athletes (p = 0.01). The onset of fatigue was earlier in category B than in category A, with greater variation in direct attack movement. The results highlight the importance of analyzing direct attacks for the best application of quick force, speed, and muscle participation, as well as identifying the onset of technical deterioration to devise a competitive strategy. These parameters may allow for precise design of conditioning sessions for elite wheelchair shooters.

Objetivo: Valorar postural, articular y muscularmente la salud lumbar de una muestra de mujeres adolescentes y medir su mejora tras la llevar a cabo un programa preventivo. Metodología: Se diseñaron una serie de ejercicios para su aplicación en la vuelta a la calma de las sesiones de Educación Física durante cuatro semanas, centrados en el desarrollo muscular lumbar, y la estabilidad y alineación raquídea. Resultados: Los resultados muestran diferencias significativas entre test y retest, en dos ítems de alineación del raquis (p < .05), pero no reportan cambios en las pruebas de estabilización raquídea y la electromiografía (p = .47). Los datos de regresión en caso de continuar la aplicación del programa indican tendencia a la mejora en esta variable. Conclusiones: La conclusión principal es resaltar la importancia de aplicar diferentes pruebas de evaluación que permitan detectar anomalías posturales y la necesidad de adoptar hábitos preventivos centrados en la práctica continuada de ejercicio físico. Palabras clave: Dolor lumbar, postura, activación muscular, adolescentes. Objective: To assess postural, joint and muscular lowback health in a sample of adolescent women and to measure their improvement after carrying out a preventive programme. Methodology: A series of exercises were designed to be applied in the return to calm during the Physical Education sessions for four weeks, focusing on lumbar muscle development, and spinal stability and alignment. Results: The results show significant differences between test and retest in two spine alignment items (p < .05), but no changes in spine stabilisation tests and electromyography (p = .47). Regression data in case of continued application of the programme indicate a trend towards improvement in this variable. Conclusions: The main conclusion is to highlight the importance of applying different assessment tests to detect postural abnormalities and the need to adopt preventive habits focused on the continued practice of physical exercise. Key words: Low-back pain, posture, muscle activation, adolescents.

Objective: To describe the relationship between bilateral electrical activity in the biceps femoris and the variation of triaxial acceleration in three 50 m sprints. Methods: Biceps femoris muscle activation and acceleration in the anterior–posterior, mediolateral, and superior–inferior axes were measured in three 50 m sprints in nine national-level sprinters. Results: There was significant asymmetry between both legs, and the variations between axes were significant between the anterior–posterior with respect to the lateral and superior–inferior, and between the lateral and superior–inferior (p < 0.05). Conclusions: Increased biceps femoris activation during running increases speed regardless of asymmetry in force application. In the maintenance of horizontal velocity, acceleration of the anterior–posterior axis is the most relevant and depends on the flexion-extension muscle actions contained in the lateral axis.

El dolor lumbar inespecífico, que afecta al 70% de la población, está vinculado a conductas sedentarias y presenta una desconexión entre anomalías estructurales y la experiencia dolorosa. Actualmente el ejercicio es considerado la primera línea de tratamiento, mejorando la biomecánica y la autogestión del dolor. El objetivo principal de este estudio piloto fue medir antes, y tras un programa de ejercicios, la activación de la musculatura central encargada de la estabilización global y local del tronco, empleando electromiografía de superficie en una hiperflexión de tronco. Se realizó un diseño de estudio prospectivo, cuasi-experimental, incluyendo un grupo de intervención con dos momentos de evaluación (pre-intervención y 4 semanas post-intervención). Se observó un descenso significativo del lapso de activación en todos los músculos estudiados tras la finalización del programa: CL derecho e izquierdo con carga (p= .015 y p= .0003 respectivamente) y MT derecho e izquierdo sin carga (p= .028 y p= .036 respectivamente), y una alta correlación de este valor con el descenso del dolor lumbar (rho= .07). El descenso del lapso de coactivación, como indicador de mayor y mejor respuesta muscular ante perturbaciones, podría ser una alternativa en la prevención del dolor lumbar inespecífico.

Background: The proper development of balance is essential in the acquisition of a correct physical condition, as well as in the evolutionary follow-up at early ages, and its periodic evaluation is very relevant in the educational environment. Objectives: The objective of this research was to design an accessible web application for static and dynamic balance assessment, based on a force platform and motion analysis software. Methods: The Single leg balance test (SLB), Tandem balance test (TBT), and Y balance test (YBT) were performed on a sample of 75 children aged 6 to 9 years. Results: The results show that static balance is more complex at an older age, greater standing height, and with eyes closed (p < 0.001). Regarding the center of pressure (COP), its variability was greater in girls owing to a lower Total Force (TF) at the time of the test (p < 0.05). Parallel observation with the Kinovea software has made it possible to elaborate a scale from 1 to 10 points for integration into an open-access web application (IMEP) to assess static and dynamic balance. Conclusions: The creation of an ad hoc application for primary school teachers and students has been possible by using validated devices obtaining a rating scale, which facilitate the monitoring of students’ functional evolution and offers the possibility of scheduling physical education sessions with a preventive approach as well as a focus on improving physical condition.

Strength is a central axis of physical activity and sets the right evolutionary direction for children and adolescents, creating adaptations that determine functional health in adulthood. Therefore, its development and supervision are essential in the future. This study aimed to measure the rate of force development (RFD) in a sample of primary and secondary school children using the deadlift exercise. In a mixed sample of 227 students aged 9–16 years, two attempts of the isometric deadlift exercise were performed using a hand-held dynamometer. Pain perception was recorded after each attempt was made. RFD evolved in both stages, with a greater difference in boys in Secondary School (p = 0.0017), and no additional differences in the rest of the variables between sexes and stages. Pain during execution was infrequent in this sample and showed no consistent association with RFD or maximal force in adjusted exploratory models. Key outcomes (maximal force and RFD_{0–200}) were summarized by sex and educational stage; RFD was computed as ΔF/Δt over 0–200 ms from contraction onset. The main findings highlight the expected progression of strength, especially in boys, and support the deadlift as an accessible alternative for strength assessment in educational settings and health-oriented recreational activities, given its low incidence of pain during execution in this population.