Search results for "Strain"
showing 10 items of 1955 documents
Effect of Training-Induced Changes in Achilles Tendon Stiffness on Muscle–Tendon Behavior During Landing
2018
During rapid deceleration of the body, tendons buffer part of the elongation of the muscle–tendon unit (MTU), enabling safe energy dissipation via eccentric muscle contraction. Yet, the influence of changes in tendon stiffness within the physiological range upon these lengthening contractions is unknown. This study aimed to examine the effect of training-induced stiffening of the Achilles tendon on triceps surae muscle–tendon behavior during a landing task. Twenty-one male subjects were assigned to either a 10-week resistance-training program consisting of single-leg isometric plantarflexion (n = 11) or to a non-training control group (n = 10). Before and after the training period, plantarf…
Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running
2019
Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric single-leg plantarflexion co…
Effects of muscle activation on shear between human soleus and gastrocnemius muscles
2017
Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both pass…
Recreational sport participation of women in Jyväskylä : constraints and motives related with women's physical activity
2008
Phenomenology of non-standard neutrino interactions
2016
Today neutrino physics is in a privileged position within the fascinating field of particle physics. From the discovery of neutrino oscillations by Super-Kamiokande in 1998, the door to physics beyond the Standard Model (SM in what follows) has been opened. This fact implies that neutrinos have to be massive in opposition to the Standard Model assumption. However, this is not a surprise completely, but it was already hinted from theoretical and experimental observations in the two decades prior to the discovery of the oscillatory phenomenon, as neutrino masses included in unification models or the observed deficit of the atmospheric and solar neutrino fluxes. As a consequence of this new pa…
A Multi-Objective Design Approach for the c Chart Considering Taguchi Loss Function
2014
The present paper proposes a multi-objective design approach for the c chart, considering in the optimization process of the chart parameters both the statistical and the economic objectives. In particular, the minimization of the hourly total quality related costs is the considered objective to carry out the economic goal, whereas the statistical objective is reached by the minimization the out-of-control average run length of the chart. A mixed integer non-linear constrained mathematical model is formulated to solve the treated multi-objective optimization problem, whereas the Pareto optimal frontier is described by the «-constraint method. In order to show the employment of the proposed …
Effects of Job Content and Physical Activity on Body Mass Index among Obese Managers of the Mexican Manufacturing Industry
2020
Mental health disorders resulting from work stressors are increasing in the Mexican manufacturing industry and worldwide. Managerial positions in these contexts are highly stressful, and although physical activity may reduce the negative effects of work stress, the relationships between these two aspects regarding their effects on the body mass index (BMI) of obese managers are scarcely studied. This article aims to study such relationships by using the Job Content Questionnaire (JCQ) dimensions with the Baecke’s physical activity questionnaire dimensions and analyzing their effects on the BMI. A sample of 255 managers from the Mexican industry, with a (BMI > 30) participated by answerin…
Selective breeding for endurance running capacity affects cognitive but not motor learning in rats
2012
The ability to utilize oxygen has been shown to affect a wide variety of physiological factors often considered beneficial for survival. As the ability to learn can be seen as one of the core factors of survival in mammals, we studied whether selective breeding for endurance running, an indication of aerobic capacity, also has an effect on learning. Rats selectively bred over 23 generations for their ability to perform forced treadmill running were trained in an appetitively motivated discrimination-reversal classical conditioning task, an alternating T-maze task followed by a rule change (from a shift-win to stay-win rule) and motor learning task. In the discrimination-reversal and T-maze …
Surrogate-assisted multicriteria optimization: Complexities, prospective solutions, and business case
2017
Complexity in solving real-world multicriteria optimization problems often stems from the fact that complex, expensive, and/or time-consuming simulation tools or physical experiments are used to evaluate solutions to a problem. In such settings, it is common to use efficient computational models, often known as surrogates or metamodels, to approximate the outcome (objective or constraint function value) of a simulation or physical experiment. The presence of multiple objective functions poses an additional layer of complexity for surrogate-assisted optimization. For example, complexities may relate to the appropriate selection of metamodels for the individual objective functions, extensive …