Search results for "Motor"
showing 10 items of 3137 documents
FUNCTIONAL EFFECT OF SHORT-TERM IMMOBILIZATION: KINEMATIC CHANGES AND RECOVERY ON REACHING-TO-GRASP
2012
Abstract Although previous investigations agree in showing significant cortical modifications related to short-term limb immobilization, little is known about the functional changes induced by non-use. To address this issue, we studied the kinematic effect of 10 h of hand immobilization. In order to prevent any movement, right handed healthy participants wore on their dominant hand a soft bandage. They were requested to perform the same reaching-to-grasping task immediately after immobilization, 1 day before (baseline 1) and in other two following days without non-use (baseline 2 and baseline 3). While no differences were found among baseline conditions, an increase of the total duration of…
Initial Evaluation of a Smoking Cessation Program Incorporating Physical Activity Promotion to Greek Adults in Antismoking Clinics
2012
The purpose of this study was to evaluate an initial application of a smoking cessation program that integrated the promotion of physical activity (PA) as a cessation aid to Greek adults in antismoking clinics. From an initial pool of 50, 12 men and 28 women from Central Greece completed the program, and 18 of them succeeded in quitting for 1 year after the program. Additionally, after the program, they increased their PA. Suggestions for future applications of the program are further discussed. peerReviewed
Changes in corticospinal excitability during an acute bout of resistance exercise in the elbow flexors
2014
Purpose Hypertrophic resistance exercise (HRE) induces central and peripheral fatigue. However, more detailed information about changes in corticospinal excitability remains to be elucidated. Methods Eleven volunteers participated in the upper arm HRE which included one repetition maximum (1 RM) control contractions and three sets of 13 RM (SET1–3). Transcranial magnetic stimulation (TMS) was applied during maximal isometric voluntary contraction (MVC) at the end of each set and during control contractions to study changes in corticospinal excitability. Electrical stimulation was used in order to measure peripheral changes. Results MVC decreased after each set when compared to control contr…
Influence of somatosensory input on motor function in patients with chronic stroke.
2004
In healthy volunteers, reduction of somatosensory input from one hand leads to rapid performance improvements in the other hand. Thus, it is possible that reduction of somatosensory input from the healthy hand can influence motor function in the paretic hand of chronic stroke patients with unilateral hand weakness. To test this hypothesis, we had 13 chronic stroke patients perform motor tasks with the paretic hand and arm during cutaneous anesthesia of the healthy hand and healthy foot in separate sessions. Performance of a finger tapping task, but not a wrist flexion task, improved significantly with anesthesia of the hand, but not the foot. This effect progressed with the duration of anes…
Effects of Rapid Weight Loss on Judo Athletes: A Systematic Review
2020
Rapid weight loss (RWL) is commonly practiced among judo athletes. Although it helps them to gain the advantage over their lighter opponents, previous studies have shown that RWL can have a negative impact on the athlete’s performance and overall well-being. This systematic review aimed to synthesize the evidence that examines the influence of rapid weight loss on physiological parameters, biomarkers, and psychological well-being in judo athletes. We followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We searched for studies on Web of Science and PubMed that elaborate on the influence of ≥5% RWL achieved over ≤7-day period in judokas. Out of 52 studie…
Inter- and intra-individual variability of paired-pulse curves with transcranial magnetic stimulation (TMS).
2002
Objectives: Previous studies have evaluated the variability of motor thresholds (MTs) and amplitude of motor-evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) within and across individuals. Here we evaluate the reproducibility and inter-hemispheric variability of measures of cortical excitability using the 'conventional' paired-pulse (PP) TMS technique. Methods: We studied PP curves of the left and right hemisphere in 10 healthy subjects on two separate days 2 weeks apart. The inter-stimulus intervals studied were 1, 3, 6, 8, 10 and 12 ms with the conditioning stimulus being 80% of the resting MT, and a single test stimulus producing MEPs of approximately 0.8 mV peak-to-pe…
Prostasomes as zinc ligands in human seminal plasma
2004
Prostasomes are small vesicles, containing zinc, secreted by prostate in human seminal plasma and showing a physiological role on sperm properties. In this study, the possible correspondence between prostasomes and a prostatic high molecular weight protein complex, recently indicated as zinc ligand, has been investigated. Isolated prostasomes, examined by scanning electron microscopy, were dialysed to evaluate their zinc binding capacity. Furthermore, seminal plasma Sephadex G-75 elution was carried out before and after prostasome removal. Prostasome preparations, containing typical vesicles of 50-500 nm, showed a positive correlation between their zinc and protein levels. They were able to…
Blood Flow Restriction Alters Motor Unit Behavior During Resistance Exercise.
2019
AbstractWe aimed to determine whether blood flow restriction (BFR) alters the characteristics of individual motor units during low-intensity (LI) exercise. Eight men (26.0±3.8 yrs) performed 5 sets of 15 knee extensions at 20% of one-repetition maximum (with and without BFR). Maximal isometric voluntary contractions (MVC) were performed before and after exercise to quantify force decrement. Submaximal isometric voluntary contractions were additionally performed for 18 s, matching trapezoidal target-force trajectories at 40% pre-MVC. EMG activity was recorded from the vastus lateralis muscle. Then, signals were decomposed to extract motor unit recruitment threshold, firing rates and action p…
Do equilibrium constraints modulate postural reaction when viewing imbalance?
2011
Abstract Action observation and action execution are tightly coupled on a neurophysiological and a behavioral level, such that visually perceiving an action can contaminate simultaneous and subsequent action execution. More specifically, observing a model in postural disequilibrium was shown to induce an increase in observers’ body sway. Here we reciprocally questioned the role of observers’ motor system in the contagion process by comparing participants’ body sway when watching displays of antero-posterior vs. lateral imbalance. Indeed, during upright standing, biomechanical constraints differ along the antero-posterior (A-P) and medio-lateral (M-L) axes; hence an impact of observers’ post…
Elderly adults delay proprioceptive reweighting during the anticipation of collision avoidance when standing.
2012
The ability to reweight visual and proprioceptive information is critical for maintaining postural stability in a dynamic environment. In this study, we examined whether visual anticipation of collision avoidance (AV) while standing could facilitate the down-weighting of altered proprioception in young and elderly adults. Twelve young (24.91 ± 6.44 years) and 12 elderly (74.8 ± 6.42 years) participants stood upright for 180 s under two task conditions: (a) quiet stance (QS) and (b) standing while anticipating virtual objects to be avoided. In order to disrupt the accuracy of proprioceptive input participants were exposed to bilateral Achilles tendon vibration during the middle 60 s of stand…