Introduction Over half of the 700,000 vertebral body fractures suffered annually by elderly Americans are unrelated to any single traumatic event (1) and the precise mechanisms of the fracture are not well understood. One possibility is that the fracture is due to a series of isolated, relatively high overloads (2); another is that it is due to lower level, more highly repetitive loads (3,4). I...

The interpolated twitch technique (ITT) is the gold standard to assess voluntary activation and central fatigue. Yet, its validity has been questioned. Here we studied how peripheral fatigue can affect the ITT. Repeated contractions at submaximal frequencies were produced by supramaximal electrical stimulations of the human adductor pollicis muscle in vivo and of isolated rat soleus fiber bundl...

The focus on fatigue for the 2012 Named Series in brain, behavior, and immunity reflects the growing wave of research examining immune underpinnings of fatigue in healthy and clinical populations. Fatigue is prevalent in the general population and in patients with a variety of medical conditions. However, the etiology of fatigue remains elusive. Psychoneuroimmunological approaches to fatigue ha...

statement of problem: the question about resistance of resin composites under rest in removable partial denture (rpd) is still unanswered. it is important to find the strongest material that withstands the applied stresses when used under rpd components. objectives: to evaluate and compare the fatigue behavior of amalgam and composite restorations used under the rest of the removable partial de...

Behavior representations in simulation environments have become increasingly sophisticated as computational power and understanding of human cognitive processes have increased. Despite improvements in the breadth and depth of models of human behavior, comparatively little research has explored how human cognition is moderated by external and internal factors. In this review paper, we focus on f...

Analytical models that predict modulus degradation in cortical bone subjected to uniaxial fatigue loading in tension and compression are presented. On the basis of experimental observations, damage was modeled as self-limiting for tension but not for compression. These mechanistic uniaxial damage models were then developed into a model for flexural fatigue of cortical bone based on laminated be...

The aim of this study is to evaluate brain regions related with excessive binocular disparity that may be linked to stereoscopic visual fatigue. In stereoscopic displays, excessive binocular disparity may generate blurring or double vision in the stereovision and induce unnatural oscillations in accommodation and vergence. These phenomena may lead to visual fatigue and activation (or deactivati...

To understand the neural factors which contribute to fatigue, it is not satisfactory to regard fatigue as occurring only when a task can no longer be performed. Changes in muscle afferent feedback, motoneuronal discharge, motor cortical output, and perceived effort develop well before an endurance limit in limb muscles. During sustained maximal contractions the discharge of motoneurones decline...