Search results for "Fatigue"
showing 10 items of 651 documents
Universal spectral profile and dynamic evolution of muscle activation: A hallmark of muscle type and physiological state
2020
The skeletal muscle is an integrated multicomponent system with complex dynamics of continuous myoelectrical activation of various muscle types across time scales to facilitate muscle coordination among units and adaptation to physiological states. To understand the multiscale dynamics of neuromuscular activity, we investigated spectral characteristics of different muscle types across time scales and their evolution with physiological states. We hypothesized that each muscle type is characterized by a specific spectral profile, reflecting muscle composition and function, that remains invariant over time scales and is universal across subjects. Furthermore, we hypothesized that the myoelectr…
The involvement of ankle muscles in maintaining balance in the upright posture is higher in elderly fallers
2016
International audience; The purpose of this study was to determine whether the mechanical contribution of ankle muscles in the upright stance differed among young adults (YA) (n = 10, age: similar to 24.3), elderly non-fallers (ENF) (n = 12, age: similar to 77.3) and elderly fallers (EF) (n = 20, age: similar to 80.7). Torque and electromyographic (EMG) activity were recorded on the triceps surae and tibialis anterior during maximum and submaximum contractions in the seated position. EMG activity was also recorded in subjects standing still. Plantar flexor (PF) and dorsal flexor (DF) torques generated in the upright posture were estimated from the torque-EMG relationship obtained during sub…
Stressor-related impairment of synaptic transmission in hippocampal slices from α-synuclein knockout mice
2004
The role of alpha-synuclein (alpha-Syn) has recently received considerable attention because it seems to play a role in Parkinson's disease (PD). Missense mutations in the alpha-Syn gene were found in autosomal dominant PD and alpha-Syn was shown to be a major constituent of protein aggregates in sporadic PD and other synucleinopathies. Under normal conditions, alpha-Syn protein is found exclusively in synaptic terminals. However, the potential participation of alpha-synuclein in maintaining and regulating synaptic efficacy is unknown. We have investigated the excitatory synaptic modulation of alpha-synuclein in CA1 pyramidal neurons, using the in vitro hippocampal slice technique. The 4-am…
Work stress, fatigue and risk behaviors at the wheel: Data to assess the association between psychosocial work factors and risky driving on Bus Rapid…
2017
This Data in Brief (DiB) article presents a hierarchical multiple linear regression model that examine the associations between psychosocial work factors and risk behaviors at the wheel in Bus Rapid Transit (BRT) drivers (n=524). The data were collected using a structured self-administrable questionnaire made of measurements of wok stress (job strain and effort- reward imbalance), fatigue (need for recovery and chronic fatigue), psychological distress and demographics (professional driving experience, hours driven per day and days working per week). The data contains 4 parts: descriptive statistics, bivariate correlations between the study variables and a regression model predicting risk be…
Towards a local approach to fatigue, for the calculation of structures, applied to continuous fibre reinforced composite materials and structures
2018
The original concept of mechanical fatigue was linked to the failure of structures and was treated at first within the framework of Fracture Mechanics. Models developed to explain this phenomenon must therefore be able to be applied to structures: changing the structure means changes to the model and its identification. It is therefore judicious to develop models capable of treating both the damage processes and also able to be used within a local framework: to this end a method based on Damage Mechanics seems appropriate. This approach has long been employed and requires only the identification of damage processes at the level of the RVE (Representative Volume Element) to be used for any s…
The self-reported stress and stressors in tram and long-haul truck drivers
2022
Work stress may compromise professional drivers’ health and driving capacity. Differences between driver groups in terms of on-duty stress are understudied. Therefore, we examined self-reported stress (Stockholm University Stress Scale) of shift-working tram and long-haul truck drivers (n = 75) across 2–3 weeks. Furthermore, stressors were self-reported retrospectively and categorised as related to the job, driving conditions, personal, or other causes. Stress levels were generally low, but moderate to high stress (≥6) was more frequently reported among the tram drivers. Stressors related to the job (54%) and driving conditions (19% of all shifts) were frequently reported among the tram and…
Aviation Crew Recovery Experiences on Outstations
2016
Abstract ACMI flight crews spend considerable time away from home on outstations. This study suggests that this long term stay carries its own considerations in regards to rest recovery with practical implications for Fatigue Risk Management as prescribed by ICAO. Four recovery experiences, Work Detachment, Control, Relaxation and Mastery, are identified and correlated with 28 crew behaviours on base. The results indicate improvement considerations for airline management organizing a long term contract with ACMI crews, in particular to increase schedule stability to improve the crew member’s sense of Control.
Effects of mixed reality head-mounted glasses during 90 minutes of mental and manual tasks on cognitive and physiological functions
2018
Background We evaluated the effects of a mixed reality (MR) head-mounted deviceon some cognitiveand physiological functions during 90 min tasks in an attempt to determine their safety for workers. Methods A total of 12 volunteers performed 90-min intellectual and manual tasks with and without MR glasses. Balance, Stroop, and memory tests were conducted before, during and after these tasks. Heart rate and electromyographic activity of some muscles were recorded. A survey was used to determine subjective fatigue, pain, or discomfort. Results Balance, heart rate, rate of perceived exertion, memory, and attention were unaffected by wearing MR glasses. Electromyographic activity increased with …
Treatment with electrical stimulation of sensory nerves improves motor function and disability status in persons with multiple sclerosis: A pilot stu…
2021
Abstract Declines in motor function are closely associated with decreases in sensory function in multiple sclerosis (MS). The purpose of our study was to assess the changes in motor function and disability status elicited by transcutaneous electrical nerve stimulation (TENS) to limb muscles of individuals with MS. Fifteen persons with MS and 11 age-matched healthy controls were evaluated before and after receiving 9 treatment sessions during which TENS was applied over the tibialis anterior and rectus femoris muscles of each leg, and over the median nerve and the thenar eminence of each hand. Each evaluation session involved completing two questionnaires (fatigue and walking limitations) an…
High versus low motivating music on intermittent fitness and agility in young well-trained basketball players
2021
The present study aimed to analyse the influence of the music level of motivation, compared to the absence of music, on intermittent fitness and agility, in a group of young well-trained basketball players. On alternate days, thirteen players (14.85 ± 0.68 years, 188 ± 0.05 cm, 75.89 ± 8.02 kg) were assessed of the V-Cut test (agility test including changes of direction) and the 30–15 Intermittent Fitness Test (30-15IFT; maximal running speed under fatigue). There were six testing sessions over three consecutive weeks, with three different randomized conditions: team-selected High Motivating Music (HMM), Low Motivating Music (LMM), and the No-Music condition (NM). Arterial oxygen saturation…