Search results for " strike"
showing 10 items of 30 documents
Kinematic characteristics of barefoot sprinting in habitually shod children
2018
Background Anecdotally, a wide variety of benefits of barefoot running have been advocated by numerous individuals. The influence of the alterations in the properties of the shoe on the running movement has been demonstrated in adults at submaximal jogging speeds. However, the biomechanical differences between shod and barefoot running in children at sprinting speeds and the potential developmental implications of these differences are still less examined. The purpose was to determine the potential differences in habitually shod children’s sprint kinematics between shod and barefoot conditions. Methods Ninety-four children (51 boys and 43 girls; 6–12 years-old; height, 135.0 ± 0.12 m; body…
Initiating running barefoot: Effects on muscle activation and impact accelerations in habitually rearfoot shod runners
2016
Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strik…
Foot Strike Pattern, Step Rate, and Trunk Posture Combined Gait Modifications to Reduce Impact Loading during Running
2019
Elevated impact loading can be detrimental to runners as it has been linked to the increased risk of tibial stress fracture and plantar fasciitis. The objective of this study was to investigate the combined effects of foot strike pattern, step rate, and anterior trunk lean gait modifications on impact loading in runners. Nineteen healthy runners performed 12 separate gait modification trials involving: three foot strike patterns (rearfoot, midfoot, and forefoot strike), two step rates (natural and 10% increased), and two anterior trunk lean postures (natural and 10-degree increased flexion). Overall, forefoot strike combined with increased step rate led to the lowest impact loading rates, a…
Achilles tendon stiffness is unchanged one hour after a marathon
2012
Overuse-induced injuries have been proposed as a predisposing factor for Achilles tendon (AT) ruptures. If tendons can be overloaded, their mechanical properties should change during exercise. Because there data are lacking on the effects of a single bout of long-lasting exercise on AT mechanical properties, the present study measured AT stiffness before and after a marathon. AT stiffness was determined as the slope of the force–elongation curve between 10 and 80% of maximum voluntary force. AT force–elongation characteristics were measured in an ankle dynamometer using simultaneous motion-capture-assisted ultrasonography. Oxygen consumption and ankle kinematics were also measured on a trea…
Running in highly cushioned shoes increases leg stiffness and amplifies impact loading
2018
AbstractRunning shoe cushioning has become a standard method for managing impact loading and consequent injuries due to running. However, despite decades of shoe technology developments and the fact that shoes have become increasingly cushioned, aimed to ease the impact on runners’ legs, running injuries have not decreased. To better understand the shoe cushioning paradox, we examined impact loading and the spring-like mechanics of running in a conventional control running shoe and a highly cushioned maximalist shoe at two training speeds, 10 and 14.5 km/h. We found that highly cushioned maximalist shoes alter spring-like running mechanics and amplify rather than attenuate impact loading. T…
Evidence of positive tectonic inversion in the north-central sector of the Sicily Channel (Central Mediterranean)
2016
In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single- and multi-channel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a ~80-km-long deformation belt, characterized by a set of WNW–ESE to NW–SE fault segments showing a poly-phasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean–Piacenzian time by dextral strike-slip motion, as a consequence of the Africa–Europe convergence; ii) releasing and restraining bend geometries forming well-developed pul…
Communicative Strategies from Cyberfemism: @Feminismosmad and the Twitter Diffusion of the 8m Strike in Madrid
2020
Resumen Tanto desde el ámbito académico como desde el movimiento feminista se discute el alcance y la relevancia de las nuevas herramientas digitales para la subversión de la agenda, el cambio en los sistemas políticos occidentales y, en suma, el fin de las desigualdades entre géneros (Zafra, 2011; Núñez Puente, 2011). Mediante un análisis cuantitativo y entrevistas semiestructuradas, estudiamos el uso de Twitter por parte de @FeminismosMad. Este perfil se enfocó en explicar la Huelga feminista, así como en motivar la participación de la ciudadanía en las diferentes actividades organizadas durante el proceso del 8M. Abstract The scope and relevance of new digital tools for subverting the do…
Multi-temporal tectonic evolution of Capo Granitola and Sciacca foreland transcurrent faults (Sicily channel)
2019
Highlights • Seismic reflection profiles evidence tectonic inversion and active strike-slip faults offshore SW Sicily foreland • Pliocene-Quaternary transpressional inversion of Late Miocene extensional basins • Transpressional fold growth rates were high in Latest Miocene-Pliocene and decreased during Quaternary Joint analysis of high-penetration multi-channel and high-resolution single-channel seismic reflection profiles, calibrated by deep well boreholes, allowed a detailed reconstruction of the Late Miocene to Recent tectonic history of the Capo Granitola and Sciacca fault systems offshore southwestern Sicily. These two fault arrays are part of a regional system of transcurrent faults t…
Impact Acceleration During Prolonged Running While Wearing Conventional Versus Minimalist Shoes.
2020
Purpose: In recent years a sub-group of minimalist runners have emerged who aim to perform physical exercise more naturally in an attempt to reduce running-related injuries. Here we aimed to determine the effect that running with minimalist footwear in a prolonged run has on footimpact accelerations. Method: Seventeen runners ran with minimalist and conventional shoes (MS and CS, respectively) in two separate sessions; the participants had experience with both footwear types. We measured the length and frequency of each stride, as well as the tibial and head impact acceleration every 5 minutes during a prolonged run (30 minutes at 80% of each individual's maximum aerobic speed). Results: Th…
Effect of fatigue and gender on kinematics and ground reaction forces variables in recreational runners.
2017
The presence of fatigue has been shown to modify running biomechanics. Overall in terms of gender, women are at lower risk than men for sustaining running-related injuries, although it depends on the factors taken into account. One possible reason for these differences in the injury rate and location might be the dissimilar running patterns between men and women. The purpose of this study was to determine the effect of fatigue and gender on the kinematic and ground reaction forces (GRF) parameters in recreational runners. Fifty-seven participants (28 males and 29 females) had kinematic and GRF variables measured while running at speed of 3.3 m s−1 before and after a fatigue test protocol. T…