Effect of static foot posture on the dynamic stiffness of foot joints during walking

Background The static foot posture has been related to the development of lower limb injuries. Research question This study aimed to investigate the dynamic stiffness of foot joints during gait in the sagittal plane to understand the role of the static foot posture in the development of injuries. Methods Seventy healthy adult male subjects with different static postures, assessed by the Foot Posture Index (FPI) (30 normal, 20 highly pronated and 20 highly supinated), were recruited. Kinematic and kinetic data were recorded using an optical motion capture system and a pressure platform, and dynamic stiffness at the different stages of the stance was calculated from the slopes of the linear regression on the flexion moment-angle curves. The effect of foot type on dynamic stiffness and on ranges of motion and moments was analysed using ANOVAs and post-hoc tests, and linear correlation between dynamic stiffness and FPI was also tested. Results Highly pronated feet showed a significantly smaller range of motion at the ankle and metatarsophalangeal joints and also a larger range of moments at the metatarsophalangeal joint than highly supinated feet. Dynamic stiffness during propulsion was significantly greater at all foot joints for highly pronated feet, with positive significant correlations with the squared FPI. Highly supinated feet showed greater dynamic stiffness than normal feet, although to a lesser extent. Highly pronated feet during normal gait experienced the greatest decrease in the dorsiflexor moments during propulsion, normal feet being the most balanced regarding work generated and absorbed. Significance Extreme static foot postures show greater dynamic stiffness during propulsion and greater absorbed work, which increases the risk of developing injuries. The data presented may be used when designing orthotics or prostheses, and also when planning surgery that modifies joint stiffness

Psicothema

Resumen tomado de la publicaciónA pesar de la importancia de la realización de los deberes escolares (tareas para casa, TPC) en el aprovechamiento académico, hoy en día existe una enorme preocupación por la baja implicación de muchos alumnos en la realización de las TPC y su efecto en el alto fracaso escolar. En este estudio, centrado en el área académica del inglés (lengua extranjera), y en base a una muestra de 591 alumnos de quinto y sexto de Educación Primaria, se analiza el rol de diferentes variables relativas a las TPC en la determinación del rendimiento académico de los estudiantes (proximal y distal), teniendo en cuenta el papel potencialmente mediador de dicha relación del uso de estrategias de autorregulación del aprendizaje y la eficacia percibida. Los resultados obtenidos muestran que el efecto de las TPC sobre el rendimiento es indirecto, a través de las variables cognitivo-motivacionales consideradas (uso de estrategias de autorregulación del aprendizaje y la autoeficacia). Estos resultados son discutidos en la línea de convertir la realización de las TPC como elemento clave para afrontar el elevado fracaso escolar.AsturiasColegio Oficial de Psicólogos de Asturias; Calle Ildefonso Sánchez del Río, 4-1 B; 33001 Oviedo; Tel. +34985285778; Fax +34985281374;Universidad de Oviedo. Facultad de Psicología; Plaza Feijoo, s. n.; 33003 Oviedo; Tel. +34985104146; Fax +34985104126;ES