Prolonged local vibration (LV) is thought to promote brain plasticity through repeated Ia afferents discharge. However, the underlying mechanisms remain unclear. This study therefore aimed at determining the acute after-effects of 30-min LV of the flexor carpi radialis muscle (FCR) on sensorimotor (S1, M1) and posterior parietal cortex (PPC) areas activity.
View Article and Find Full Text PDFIntroduction: Cerebral palsy (CP) presents a complex neurodevelopmental disorder with a spectrum of motor impairments stemming from early brain injury. Whereas CP is traditionally viewed as a non-progressive condition, emerging evidence suggests a progressive decline in mobility and function, particularly in adulthood. Despite the prevalence of self-reported age-related gait decline in adults with CP, objective evidence supporting this phenomenon remains limited.
View Article and Find Full Text PDFPurpose: The aim of this study was to compare performance fatigability between young (n = 13; 18-35 yr.; 23.5 ± 3.
View Article and Find Full Text PDFThe response of spinal motoneurons to synaptic input greatly depends on the activation of persistent inward currents (PICs), the contribution of which can be estimated through the paired motor unit technique. Yet, the intra-session test-retest reliability of this measurement remains to be fully established. Twenty males performed isometric triangular dorsiflexion contractions to 20 and 50 % of maximal torque at baseline and after a 15-min resting period.
View Article and Find Full Text PDFPurpose: The perception of effort exerts influence in determining task failure during endurance performance. Training interventions blending physical and cognitive tasks yielded promising results in enhancing performance. Motor imagery can decrease the perception of effort.
View Article and Find Full Text PDFIntroduction: Central nervous system excitability depends on the task performed, muscle group solicited, and contraction type. However, little is known on corticospinal and motoneuronal excitability measured during locomotor exercise. This study aimed at determining the reliability of motor-evoked potentials (MEP) and thoracic motor-evoked potentials (TMEP) in dynamic mode during unfatiguing and fatiguing cycling exercise.
View Article and Find Full Text PDFProlonged local vibration (LV) can induce neurophysiological adaptations thought to be related to long-term potentiation or depression. Yet, how changes in intracortical excitability may be involved remains to be further investigated as previous studies reported equivocal results. We therefore investigated the effects of 30 min of LV applied to the right flexor carpi radialis muscle (FCR) on both short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF).
View Article and Find Full Text PDFIntroduction/purpose: Recently, the use of transcutaneous spinal cord stimulation (TSCS) has been proposed as a viable alternative to the H-reflex. The aim of the current study was to investigate to what extent the two modes of spinal cord excitability investigation would be similarly sensitive to the well-known vibration-induced depression.
Methods: Fourteen healthy participants (8 men and 6 women; age: 26.
Motor control, including locomotion, strongly depends on the gravitational field. Recent developments such as lower-body positive pressure treadmills (LBPPT) have enabled studies on Earth about the effects of reduced body weight (BW) on walking and running, up to 60% BW. The present experiment was set up to further investigate adaptations to a more naturalistic simulated hypogravity, mimicking a Martian environment with additional visual information during running sessions on LBPPT.
View Article and Find Full Text PDFPurpose: This study aimed to compare performance and fatigability between young (n = 13; 18-30 yr), old (n = 13; 60-80 yr), and very old (n = 12; >80 yr) men during a single-joint isometric (ISO) and concentric (CON) task performed on an isokinetic dynamometer and a cycling (BIKE) task.
Methods: Participants randomly performed incremental tasks consisting of stages of 75 contractions (i.e.
Originally developed for astronauts, lower body positive pressure treadmills (LBPPTs) are increasingly being used in sports and clinical settings because they allow for unweighted running. However, the neuromuscular adjustments to unweighted running remain understudied. They would be limited for certain lower limb muscles and interindividually variable.
View Article and Find Full Text PDFFatigue is a major symptom in many diseases, often among the most common and severe ones and may last for an extremely long period. Chronic fatigue impacts quality of life, reduces the capacity to perform activities of daily living, and has socioeconomical consequences such as impairing return to work. Despite the high prevalence and deleterious consequences of fatigue, little is known about its etiology.
View Article and Find Full Text PDFThe response of spinal motoneurons to synaptic input greatly depends on the activation of persistent inward currents (PICs), which in turn are enhanced by the neuromodulators serotonin and noradrenaline. Local vibration (LV) induces excitatory Ia input onto motoneurons and may alter neuromodulatory inputs. Therefore, we investigated whether LV influences the contribution of PICs to motoneuron firing.
View Article and Find Full Text PDFThis systematic review documents the protocol characteristics of studies that used neuromuscular electrical stimulation protocols (NMES) on the plantar flexors [through triceps surae (TS) or tibial nerve (TN) stimulation] to stimulate afferent pathways. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, was registered to PROSPERO (ID: CRD42022345194) and was funded by the Greek General Secretariat for Research and Technology (ERA-NET NEURON JTC 2020). Included were original research articles on healthy adults, with NMES interventions applied on TN or TS or both.
View Article and Find Full Text PDFPurpose: The effectiveness of a neuromuscular electrical stimulation (NMES) program has been shown to be proportional to the maximal evocable torque (MET), which is potentially influenced by pulse characteristics such as duration and frequency. The aim of this study was to compare MET between conventional and wide-pulse NMES at two different frequencies.
Methods: MET-expressed as a percentage of maximal voluntary contraction (MVC) torque-and maximal tolerable current intensity were quantified on 71 healthy subjects.
Acute effects of prolonged local vibration (LV) at the central nervous system level have been well investigated demonstrating an altered motoneuronal excitability with a concomitant increase in cortical excitability. While applying LV during isometric voluntary contraction is thought to optimize the effects of LV, this has never been addressed considering the acute changes in central nervous system excitability. In the present study, nineteen healthy participants were engaged in four randomized sessions.
View Article and Find Full Text PDFMonitoring fatigue is now commonly performed in athletes as it can directly impact performance and may further increase the risk of injury or overtraining syndrome. Among the exercise-induced peripheral alterations, low-frequency fatigue (LFF) assessment is commonly restricted to in-lab studies. Measuring LFF on-field would allow athletes and coaches to assess muscle fatigability on a regular basis.
View Article and Find Full Text PDFPurpose: The aim of this study was to investigate the effects of an acute high-intensity, long-duration passive stretching session of the plantar flexor muscles, on maximal dorsiflexion (DF) angle and passive stiffness at both ankle joint and gastrocnemius medialis (GM) muscle levels in children with unilateral cerebral palsy (CP).
Methods: 13 children [mean age: 10 years 6 months, gross motor function classification system (GMFCS): I] with unilateral CP underwent a 5 min passive stretching session at 80% of maximal DF angle. Changes in maximal DF angle, slack angle, passive ankle joint and GM muscle stiffness from PRE- to POST-intervention were determined during passive ankle mobilization performed on a dynamometer coupled with shear wave elastography measurements (i.
In the present study, we aimed to provide a robust comparison of the fatigability of the knee extensors following isometric (ISO) and concentric (CON) tasks. Twenty young adults (25 ± 4 yr, 10 women) randomly performed the ISO and CON quadriceps intermittent fatigue test, consisting of ten (5 s on/5-s off, ISO) or one-hundred (0.5-s on/0.
View Article and Find Full Text PDFObjectives: The aim of the current study was to investigate the level of cardiorespiratory fitness and neuromuscular function of ICU survivors after COVID-19 and to examine whether these outcomes are related to ICU stay/mechanical ventilation duration.
Design: Prospective nonrandomized study.
Setting: Patients hospitalized in ICU for COVID-19 infection.
J Vasc Surg Venous Lymphat Disord
September 2022