The influence of stride-length on plantar foot-pressures and joint moments

AbstractPurposeJoint moments have been acknowledged as key factors in understanding gait abnormalities. Gait velocity is further known to affect joint moments and foot pressures. Keeping gait velocity constant is thus a strategy to cancel out the influence of different preferred gait speed between groups. But even if gait velocity is controlled, individuals can choose different stride length–stride frequency combinations to cope with an imposed gait velocity.ScopeTo understand the influence of stride frequency–stride length on joint moments and plantar pressures.MethodsTwenty healthy young adults had to cross an 8m walkway with a walking speed of 1.3ms−1. The wooden walkway was equipped with a force and a pressure platform. While walking speed was kept constant each participant walked with five different imposed stride lengths (SL): preferred (SL0); with a decrease of 10% (SL−10); with a decrease of 20% (SL−20); with an increase of 10% (SL+10) and with an increase of 20% (SF+20).ResultsAnkle and knee joint moments significantly decreased with a decrease in SL. A significant (p<.05) lower peak pressure was achieved with a decreased SL under the heel, toes and midfoot.Discussion/conclusionThe results showed that a change in stride lengths alters both, joint moments and foot pressures with clinically interesting indications. Redistribution of joint moments in the elderly for example might rather result from decreased SL than from age

THE INFLUENCE OF THIRD GENERATION ARTIFICIAL SOCCER TURF CHARACTERISTICS ON GROUND REACTION FORCES DURING RUNNING

The aim of this study was to determine the effect of different artificial soccer turf pitches on the ground reaction forces of running soccer players. For this purpose ground reaction forces were determined for twenty soccer players while they ran at three different speeds across a 25 meter long track covered with a third generation artificial soccer turf. Three different pitches, two FIFA 1star and one FIFA 2star, were examined. There was no difference between the two 1star systems in the peak vertical and horizontal ground reactions forces. Data on the 2star system was equivocal due to a too small sample size. It is concluded that surface characteristics influence the loading of the human muscle-skeletal system more subtly than initially anticipated. A more detailed biomechanical analysis of the events during impact is required to identify the critical loading parameters

The Association Between Objectively Measured Physical Activity and Academic Achievement in Dutch Adolescents: Findings From the GOALS Study

The main goal of this study was to investigate the association between objectively measured physical activity and academic achievement in adolescents

Active commuting to school, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers

Background: The current study examined the associations between active commuting to school, cognitive performance, and academic achievement in Dutch adolescents. In addition, it was explored whether these associations were moderated by sex and mediated by depressive symptoms. Methods: Students in grades 7 and 9 (N = 270; mean age 13.4 years; 53% boys) were included. Active commuting to school was measured objectively by an ActivPAL3™ accelerometer. Cognitive performance was measured by the d2 Test of attention (key components of executive functioning) and the Symbol Digit Modalities Test (information-processing speed). Academic achievement was determined by the mean of the school grades obtained in Dutch, mathematics and English. Depressive symptoms were self-reported. Results: Active commuting to school constituted 28% of the total amount of time spent moving per week. Active commuting to school was not significantly associated with cognitive performance and academic achievement, overall. However, active commuting to school was positively associated with performance on the d2 Test of attention in girls (β = .17, p = .037), but not in boys (β = −.03, p =.660). The associations were not mediated by depressive symptoms. Conclusions: The associations between active commuting to school and cognitive performance and academic achievement are weak and might be moderated by sex, while the greatest benefits on cognition due to active commuting to school might be with regard to executive functioning. Future studies might make use of experimental designs, because causal relations between active commuting to school and cognitive performance or academic achievement would provide important implications for both education and public health.This research was supported by the NIHC (Nationaal Initiatief Hersenen & Cognitie [National Initiative Brain & Cognition]) funded by FES (Fonds Economische Structuurversterking [Fund Economic Structure Reinforcement])

Physical activity, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers

Van Dijk, M. L., De Groot, R. H. M., Savelberg, H. C. M., Van Acker, F. H. M., & Kirschner, P. A. (2013, 7 November). Physical activity, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers. Paper presentation at ICO National Fall School 2013, Maastricht, The Netherlands.Presentation of the associations between physical activity and cognitive performance, and academic achievement in adolescents. Physical activity levels were measured in 440 secondary school students during one full week using accelerometers

Objectively versus subjectively measured physical activity: associations with cognition and academic achievement in adolescents

Van Dijk, M. L., De Groot, R. H. M., Savelberg, H. C. M., Van Acker, F. H. M., & Kirschner, P. A. (2013, 25 May). Objectively versus subjectively measured physical activity: associations with cognition and academic achievement in adolescents. Poster presentation at the ISBNPA conference 2013, Ghent, Belgium.An increasing amount of research supports a positive association between physical activity and cognitive performance or academic achievement. The majority of these studies focused on children or older adults, while less is known about these associations in adolescents. Moreover, in studies on the associations between physical activity and cognitive performance / academic achievement in adolescents, questionnaires (i.e. self-report) were used to measure physical activity. This subjective measure of physical activity has been found to have several limitations, such as social desirability and recall bias. Therefore, associations between objectively measured physical activity and cognition / academic achievement in Dutch adolescents, controlling for relevant covariates, were investigated in this stud

Objectively measured physical activity is negatively associated with academic achievement in adolescents:The GOALS Study

Van Dijk, M. L., De Groot, R. H. M., Van Acker, F. H. M., Savelberg, H. C. M., & Kirschner, P. A. (2012, 7 November). Objectively measured physical activity is negatively associated with academic achievement in adolescents: The GOALS Study. Roundtable presentation at ICO Fall School 2012, Girona, Spain.This cross sectional study showed that physical activity is negatively associated with academic achievement and not significantly associated with cognitive performance in adolescent