Search results for "Myograph"

Source unreliability decreases but does not cancel the impact of social information on metacognitive evaluations

2015

International audience; Through metacognitive evaluations, individuals assess their own cognitive operations with respect to their current goals. We have previously shown that non-verbal social cues spontaneously influence these evaluations, even when the cues are unreliable. Here, we explore whether a belief about the reliability of the source can modulate this form of social impact. Participants performed a two-alternative forced choice task that varied in difficulty. The task was followed by a video of a person who was presented as being either competent or incompetent at performing the task. That person provided random feedback to the participant through facial expressions indicating ag…

Métodos de entrenamiento de fuerza alternativos para incrementar la activación muscular en ejercicios de empuje

2016

Introducción. Los movimientos en los que se empuja o presiona con los brazos a una resistencia externa constituyen un elemento clásico dentro de los programas de entrenamiento de la fuerza. Tradicionalmente se han empleado ejercicios convencionales con pesos libres y máquinas con los que se conseguía alcanzar intensidades de activación muscular altas. Sin embargo, tratando de incrementar en mayor medida la intensidad en este tipo de ejercicios, durante los últimos años se han comenzado a utilizar nuevos medios y métodos alternativos (por ejemplo utilizando dispositivos de suspensión, resistencia elástica o tratando de activar músculos de forma selectiva). No obstante, es escasa la evidencia…

Physiological loading during normal daily life and exercise assessed with electromyography

2014

Combined strength and endurance exercise induced fatigue and recovery

2012

Muscular fatigue is usually defined as the inability to maintain a given exercise intensity or adequate muscle force and therefore maximal isometric force, neural activation and fast force production capacity have often used determinants of acute fatigue. The purpose of the present study was to measure the acute effects of combined strength and endurance exercise on force production, muscle activation and work economy. In addition this study investigated the rate of recovery comparing the active and passive recovery models and the association of the initial fitness levels of subjects. 16 (27 ± 4 years old) male reservists performed combined strength (5x10x70%RM leg-press) and endurance (5x1…

Responsiveness of Electromyographically Assessed Skeletal Muscle Inactivity – methodological exploration and implications for health benefits

2022

Abstract Prolonged sedentary behaviour is detrimental to health due to low contractile activity in large lower extremity muscle groups. This muscle inactivity can be measured with electromyography (EMG), but it is unknown how methodological factors affect responsiveness longitudinally. This study aimed to rank 16 different EMG inactivity thresholds based on their responsiveness (absolute and standardized effect size, responsiveness) using data from a randomized controlled trial targeted at reducing and breaking up sedentary time (InPact, ISRCTN28668090). EMG inactivity duration and usual EMG inactivity bout duration (weighted median of bout lengths) were measured from large lower extremity …

Ergonomic Comparison of a Sit-Stand Workstation With a Traditional Workstation in Visual Display Unit Work

2013

Purpose: To compare ergonomics of an electrically adjustable sit-stand workstation with a traditional workstation in video display unit (VDU) work. Methods: Twelve female workers (aged 27-53 years) participated in this experimental study. Electromyography, wrist postures, subjective assessments, and productivity were used to make the ergonomic comparison. Results: The muscle activity of the right trapezius (p=0.01) and left wrist extensors (p=0.02), extension of the right (p=0.05) and left (p=0.002) wrist, and perceived strain of the arms (p=0.05) were lower and productivity was better (p=0.02) when the workers used a low-sitting, high-sitting, or standing posture at the sit-stand workstati…

Muscle function in monozygotic female twin pairs discordant for hormone replacement therapy

2011

Introduction: Postmenopausal monozygotic twin pairs discordant for hormone replacement therapy (HRT) provide an advantageous study design controlling for genetic background for elucidating the relationships between aging, sex hormone levels, muscle strength, contractile capacity, and fatigability. Methods: Thirteen postmenopausal monozygotic twin pairs discordant for HRT were measured for maximal voluntary torque (MVC) and twitch characteristics using electrical stimulation before and after intermittent dynamic plantarflexor exercise until exhaustion. Results: Peak twitch torque was 32% higher in HRT users than in their non-HRT, genetically identical sisters (P = 0.002), but MVC did not dif…

The Association between Masticatory Muscles Activation and Foot Pressure Distribution in Older Female Adults: A Cross-Sectional Study

2023

The association between craniofacial muscles and postural control is well-known because of numerous anatomical connections. However, there are a few conflicting studies that correlated the activity of the masticatory muscles with the distribution of body weight pressure on the feet, which can strongly influence balance. Therefore, the purpose of our study was to evaluate the association between the masseter and temporalis muscle activity and foot pressure distribution. Fifty-two women were recruited, and baropodometric and EMG analyses of the masseter and temporalis baseline activities were analyzed. An ipsilateral association was found between the right temporal muscle activity and the rig…

Quadriceps and hamstring muscle EMG activity during a football match

2012

Roudi Kalema (2012). Quadriceps and hamstring muscle EMG activity during a football match. Department of Biology of Physical, University of Jyvaskyla. Master’s Thesis in Exercise Physiology. 58 pages. Fatigue represents a reduction in the ability of muscle to generate force and in the context of football, it has been often related with injury. Surface electromyography is a valuable technique for evaluating muscle activation and fatigue but it has never been applied during a football match. The development of washable textile electrodes has opened up possibilities to investigate muscular activity in non-laboratory settings, without skin preparation and wires hanging around the body. It has a…

Effects of water immersion on soleus neuromuscular parameters

2017

Aquatic rehabilitation is a widely used tool for injury prevention or rehabilitation. The underlying neuromuscular mechanisms during immersion are less known due to methodological issues. The following study main purpose to assess neuromuscular functions and muscle architecture changes within immersed condition. The physical properties of water to the human body are well understood, as well as its effect on the cardiorespiratory system. While the Hoffmann reflex, as a tool to assess neuromuscular changes on dry land is widely examined, it has been rarely used during immersion. The effect of water immersion on muscle behavior is also unknown. In this study control values were recorded in sit…