Persistent inward currents (PICs) are crucial for initiation, acceleration, and maintenance of motoneuron firing. As PICs highly sensitive to synaptic inhibition facilitated by serotonin noradrenaline, we hypothesised that both reciprocal (RI) induced antagonist nerve stimulation whole-body relaxation (WBR) would reduce in humans. To test this, estimated using the well-established paired motor unit (MU) technique. High-density surface electromyograms were recorded from gastrocnemius medialis...

The response of spinal motoneurons to synaptic input greatly depends on the activation persistent inward currents (PICs), which in turn are enhanced by neuromodulators serotonin and noradrenaline. Local vibration (LV) induces excitatory Ia onto may alter neuromodulatory inputs. Therefore, we investigated whether LV influences contribution PICs motoneuron firing. This was assessed voluntary contractions with concurrent, ongoing LV, as well after a bout prolonged LV. High-density surface...

Spinal motoneuron firing depends greatly on persistent inward currents (PICs), which in turn are facilitated by the neuromodulators serotonin and noradrenaline. The aim of this study was to determine whether jaw clenching (JC) mental stress (MS), may increase neuromodulator release, facilitate PICs human motoneurons. paired motor unit (MU) technique used estimate PIC contribution firing. Surface electromyograms were collected using a 32-channel matrix gastrocnemius medialis (GM) during...

New Findings What is the central question of study? are effects caffeine on neuromuscular function in a non‐fatigued state and during fatiguing exercise? main finding its importance? In state, decreased duration silent period evoked by transcranial magnetic stimulation. Caffeine‐induced reduction inhibitory mechanisms nervous system before exercise was associated with an increased performance. Individuals who benefit from ingestion may experience lower perception effort accelerated recovery...

Gonçalves, BM, Mesquita, RNO, Tavares, F, Brito, J, Correia, P, Santos, and Mil-Homens, P. A new portable device to reliably measure maximal strength rate of force development hip adduction abduction. J Strength Cond Res 36(9): 2465-2471, 2022-Groin injuries are a major issue in sports involving kicking or quick changes direction. Decreased abduction have been indicated as one the main risk factors for groin injury. The methods currently available reliable but highly dependent on evaluator...

Simultaneous application of tendon vibration and neuromuscular electrical stimulation (NMES) induces an involuntary sustained torque. We examined the effect different NMES parameters (intensity, pattern pulse width) on magnitude evoked torque.Plantar flexor torque was recorded during 33-s Achilles with simultaneous 20-Hz bouts triceps surae (n = 20; 13 women). Intensity set to elicit 10, 20 or 30% maximal voluntary contraction (MVC), width narrow (0.2 ms) wide (1 ms), stimulus varied (5 ×...

The world population is ageing. According to the United Nation's 2019 World Population Prospects, by 2050, one in six people will be over age 65, a striking increase from 11 2019. More than ever, we need elucidate age-related adaptations of neuromuscular system implement interventions which can maintain or improve function older adults. We rely on firing characteristics our spinal motoneurons produce force, and so, perform daily activities such as regulating pedal force while driving,...

Two studies were conducted to examine the effects of ice slushy ingestion (ICE) and cold water immersion (CWI) on thermoregulatory sweat responses during constant (study 1) self-paced 2) exercise. In study 1, 11 men cycled at 40–50% peak aerobic power for 60 min (33.2 ± 0.3°C, 45.9 0.5% relative humidity, RH). 2, perceived exertion (RPE) equivalent 15 (33.9 0.2°C 42.5 3.9%RH). both studies, each trial was preceded by 30 CWI (~22°C), ICE or no cooling (CON). Rectal temperature (Tre), skin...

Abstract Purpose Persistent inward calcium and sodium currents (PICs) are crucial for initiation maintenance of motoneuron firing, thus muscular force. However, there is a lack data describing the effects fatiguing exercise on PIC activity in humans. We simultaneously applied tendon vibration neuromuscular electrical stimulation (VibStim) before after exercise. VibStim induces self-sustained muscle that proposed to result from activation. Methods Twelve men performed 5-s maximal isometric...

The response of spinal motoneurons to synaptic input greatly depends on the activation persistent inward currents (PICs), contribution which can be estimated through paired motor unit technique. Yet, intra-session test-retest reliability this measurement remains fully established. Twenty males performed isometric triangular dorsiflexion contractions 20 and 50 % maximal torque at baseline after a 15-min resting period. High-density electromyographic signals (HD-EMG) tibialis anterior were...

Mesquita, RNO, Latella, C, Ruas, CV, Nosaka, K, and Taylor, JL. Contraction velocity of the elbow flexors assessed by tensiomyography: A comparison between formulas. J Strength Cond Res 37(10): 1969-1977, 2023-Muscle contraction ( Vc ) tensiomyography is a promising measure for athlete profiling. Multiple formulas are used to estimate , but most suitable method yet be established. Fifteen adults (2 female subjects) underwent assessment biceps brachii muscle at 10, 45 90° flexion on 2...

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Summary Study aim: To determine the reliability and validity of a time domain heart rate variability (HRV) index during free-living physical activity (FLPA). Material methods: Eight white-collar workers participated in this study. RR intervals (time between consecutive R-peaks PQRS complex) were recorded using Polar V800 (HR) monitor upon awakening at work on 16 different days. A total 127 cycles sitting periods followed by walking breaks included for pairwise analysis reliability. The HR...