Gabriel S Trajano

Gabriel S Trajano
Queensland University of Technology | QUT · School of Exercise & Nutrition Sciences

PhD

About

78
Publications
37,768
Reads
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1,303
Citations
Additional affiliations
January 2015 - July 2015
Neuroscience Research Australia
Position
  • PostDoc Position
September 2010 - November 2014
Edith Cowan University
Position
  • PhD Student
Education
October 2010 - March 2014
Edith Cowan University
Field of study
  • Sports Sciences
February 2008 - February 2010
Salgado de Oliveira University
Field of study
  • Neuromuscular fatigue
February 2006 - June 2007
Universidade Gama Filho
Field of study
  • Exercise Physiology

Publications

Publications (78)
Article
Prolonged (≥60 s) passive muscle stretching acutely reduces maximal force production at least partly through a suppression of efferent neural drive. The origin of this neural suppression has not been determined, however some evidence suggests that reductions in the amplitude of persistent inward currents (PICs) in the motoneurons may be important....
Article
Full-text available
Background Post-stroke muscle stiffness is a major challenge in the rehabilitation of stroke survivors, with no gold standard in clinical assessment. Muscle stiffness is typically evaluated by the Modified Ashworth Scale or the Tardieu Scale; however, these can have low reliability and sensitivity. Ultrasound elastography is an advanced imaging tec...
Article
Full-text available
Muscle power has been reported to be critical in counteracting age-related declines in functional performance. Muscle power output in functional performance exercises can be greatly improved in a short period of time (i.e., ≤ 12 weeks) using specific exercise interventions such as power training (i.e., exercises attempting to move loads ranging fro...
Preprint
Full-text available
A well-coordinated control of motor neuronal persistent inward currents (PICs) via diffuse neuromodulation and local inhibition is essential to ensure motor units discharge at required times and frequencies. Current best estimates indicate that PICs are reduced in older adults; however, it is not yet known whether PIC facilitation-inhibition contro...
Article
Full-text available
This study compared the acute responses of three neuromuscular electrical stimulation (NMES) methods on muscle torque‐time integral (TTI) and neuromuscular fatigue. Narrow‐pulse (0.2‐ms; NP), wide‐pulse (1‐ms; WP), and tendon vibration superimposed onto wide‐pulse (WP+VIB)‐NMES conditions were applied to sixteen healthy individuals (n = 16) in thre...
Article
Full-text available
Declines in muscle force, power, and contractile function can be observed in older adults, clinical populations, inactive individuals, and injured athletes. Passive heating exposure (e.g., hot baths, sauna, or heated garments) has been used for health purposes, including skeletal muscle treatment. An acute increase in muscle temperature by passive...
Conference Paper
Background and aim: Serotonin and noradrenaline release in the spinal cord are critical to motoneuron firing. Without the influence of these neuromodulators, we would not be able to produce more than 40% of our maximum motor output. An important part of this neuromodulation is the activation of persistent (long-lasting) inward currents (PICs) that...
Conference Paper
Background: Persistent inward currents (PICs) in motoneurons greatly influence their responsiveness to synaptic input. As PICs are enhanced by monoamines, we hypothesised that increased noradrenaline release induced by mental stress would increase PICs in humans. Methods: Surface electromyograms (EMG) collected using a 32-electrode matrix on gastr...
Preprint
Full-text available
Objectives Deficits in muscle performance could be a consequence of a reduced ability of a motor neuron to increase the rate in which it discharges. This study aimed to investigate motor unit (MU) discharge properties of each Triceps surae muscle (TS), and TS torque steadiness during submaximal intensities in runners with Achilles tendinopathy (AT)...
Article
Full-text available
Key points: Spinal motoneurons transmit signals to skeletal muscles to regulate their contraction. Motoneuron firing partly depends on their intrinsic properties, such as the strength of persistent (long-lasting) inward currents (PICs) that make motoneurons more responsive to excitatory input. In this study, we demonstrate that both reciprocal inh...
Article
Full-text available
Objectives This study aimed to investigate short-interval intracortical inhibition (SICI) and muscle function in the Triceps surae of runners with mid-portion Achilles tendinopathy (AT). Methods Runners with (n=11) and without (n=13) AT were recruited. Plantar flexor isometric peak torque and rate of torque development (RTD) were measured using an...
Article
Full-text available
PurposeCortical mechanisms may contribute to weakness in participants with previous hamstring strain injury. This study aims to examine intra-cortical inhibition (SICI) and corticospinal excitability in previously injured participants.Methods In this cross-sectional study, TMS was used to examine SICI, silent period, silent period: MEP ratios and a...
Article
Full-text available
Surface electromyography amplitudes are commonly measured in acute sports and exercise science studies to make inferences about muscular strength, performance, and hypertrophic adaptations that may result from different exercises or exercise-related variables. Here, we discuss the presumptive logic and assumptions underlying these inferences, focus...
Article
Nervous system maladaptation is linked to the loss of maximal strength and motor control with aging. Motor unit discharge rates are a critical determinant of force production; thus, lower discharge rates could be a mechanism underpinning maximal strength and motor control losses during aging. This meta-analysis summarized the findings of studies co...
Article
Full-text available
Background: Torque steadiness can be impaired in people with Huntington's disease (HD) and worsen with disease advancement. However, existing studies have several methodological oversights. Studies have used absolute torque targets, which do not account for differences in maximal torque capacity between people. Furthermore, despite its known influ...
Article
While muscle stretching has been commonly used to alleviate pain, reports of its effectiveness are conflicting. The objective of this review is to investigate the acute and chronic effects of stretching on pain, including delayed onset muscle soreness. The few studies implementing acute stretching protocols have reported small to large magnitude de...
Article
Persistent deficits in strength and voluntary activation have been observed in athletes with a history of hamstring strain injury. The mechanisms contributing to these deficits are poorly understood and consequently may not be appropriately addressed during rehabilitation. This study aimed to investigate the impact of intended knee flexor contracti...
Article
Age-related deterioration within both motoneuron and monoaminergic systems should theoretically reduce neuromodulation by weakening motoneuronal persistent inward current (PIC) amplitude. However, this assumption remains untested. Surface electromyographic signals were collected using two 32-channel electrode matrices placed on soleus and tibialis...
Preprint
Full-text available
Objectives: This study aimed to investigate short-interval intracortical inhibition (SICI) and muscle function in the Triceps surae of runners with mid-portion Achilles tendinopathy (AT). Methods: Runners with (n=11) and without (n=13) AT were recruited. Plantar flexor isometric peak torque and rate of torque development (RTD) were measured using...
Article
Full-text available
Hamstring strain injury (HSI) is a common and costly injury in many sports such as the various professional football codes. Most HSIs have been reported to occur during high intensity sprinting actions. This observation has led to the suggestion that a link between sprinting biomechanics and HSIs may exist. The aim of this literature review was to...
Article
Evidence for the effectiveness of acute and chronic stretching for improving range of motion is extensive. Improved flexibility can positively impact performances in activities of daily living and both physical and mental health. However, less is known about the effects of stretching on other aspects of health such as injury incidence and balance....
Preprint
Full-text available
Age-related deterioration within both motor neurones and monoaminergic systems should theoretically reduce neuromodulation by weakening motor neuronal persistent inward current (PIC) amplitude. However, this assumption remains untested. Surface electromyographic signals were collected using two 32-channel electrode matrices placed on soleus and tib...
Article
Full-text available
Objective: We reviewed and appraised the existing evidence of in vivo manifestations of residual force enhancement in human skeletal muscles and assessed, through a meta-analysis, the effect of an immediate history of eccentric contraction on the subsequent torque capacity of voluntary and electrically evoked muscle contractions. Methods: Our searc...
Article
This study tested if estimates of persistent inward currents (PICs) in the plantar flexors would increase with the level of voluntary drive. High-density surface electromyograms were collected from soleus and gastrocnemius medialis of 21 participants during ramp-shaped isometric contractions to 10%, 20%, and 30% (torque rise and decline of 2%/s and...
Article
Prolonged static muscle stretching transiently reduces maximal muscle force, and this force loss has a strong neural component. In this review, we discuss the evidence suggesting that stretching reduces the motoneuron's ability to amplify excitatory drive. We propose a hypothetical model in which stretching causes physiological relaxation, reducing...
Article
To investigate changes in muscle spindle sensitivity with early and late soleus reflex responses via tendon taps and transcranial magnetic stimulation, respectively, after an acute bout of prolonged static plantar flexor muscle stretching. Seventeen healthy males were tested before and after 5 min (5 ´ 60-s stretches) of passive static stretching o...
Article
Background Few studies have assessed physical functioning in glioma patients with grade II, III, IV glioma prior to undergoing adjuvant radiation with or without chemotherapy. The aim of this study was to describe the baseline physical functioning capacity of patients with glioma prior to adjuvant therapy compared to validated cut-offs required to...
Article
Full-text available
Objective To test the effects of hot-water immersion on the rapid force production and parameters of neuromuscular function in healthy adults. Design Cross-sectional study. Methods Fifteen healthy adults (24.9 ± 5.6 years; 178 ± 11.4 cm; 72.8 ± 16.2 kg) performed neuromuscular assessments before, after and ∼15 min after either 90 min of 42 °C (ho...
Article
Full-text available
Whereas a variety of pre-exercise activities have been incorporated as part of a “warm-up” prior to work, combat, and athletic activities for millennia, the inclusion of static stretching (SS) within a warm-up has lost favor in the last 25 years. Research emphasized the possibility of SS-induced impairments in subsequent performance following prolo...
Article
Full-text available
Purpose: To analyse the effect of resistance training (RT) performed until volitional failure with low-, moderate- and high-loads on muscle hypertrophy and muscle strength in healthy adults; and assess the possible participant-, design-, and training-related covariates which may affect the adaptations. Methods: Using PRISMA guidelines, MEDLINE, CIN...
Preprint
Full-text available
Nervous system maladaptation is linked to the loss of muscle force production and motor control with aging. However, the mechanisms specifically underpinning these muscle functional limitations remain unclear. Motoneuron discharge rates are a critical determinant of force production and strongly impact motor control; thus, lower discharge rates cou...
Preprint
Full-text available
Aim: To test the hypothesis that estimates of persistent inward currents in the human plantar flexors would increase with the level of voluntary drive. Methods: Twenty-one participants volunteered for this study (29.2±2.6 years). High-density surface electromyograms were collected from soleus and gastrocnemius medialis during ramp-shaped isometric...
Article
Full-text available
PurposeTo determine the vastus lateralis muscle temperature kinetics during and after passive heating, to exam the effect of sex on thermoregulatory responses, and the thermal safety and tolerance of the 42 °C hot-water immersion protocol.Methods Thirty participants (15 males, 15 females) underwent a 2 h 42 ºC hot-water immersion to the waist level...
Article
Full-text available
The aim of the present study was to quantify explosive joint torque or the ability to develop joint torque rapidly, typically measured as the rate of torque development, in individuals with prodromal Huntington's disease and healthy controls and its associations with measures of disease burden and striatal pathology. Twenty prodromal Huntington's d...
Article
Background Exercise is recognised as an adjunct therapy for breast cancer patients; however, little is known about the resistance training dose–response. We conducted a systematic review and meta-regression to examine the resistance training dose–response (i.e., volume and intensity) in breast cancer patients undergoing primary treatment.Methods Se...
Article
Full-text available
Caffeine improves cycling time trial performance through enhanced motor output and muscle recruitment. However, it is unknown if caffeine further increases power output entropy. To investigate the effects of caffeine effects on cycling time trial performance and motor output entropy (MOEn), nine cyclists (VO2MAX of 55 ± 6.1 mL.kg.-1min⁻¹) performed...
Preprint
Full-text available
Prolonged (≥60 s) passive muscle stretching acutely reduces maximal force production at least partly through a suppression of efferent neural drive. The origin of this neural suppression has not been determined, however some evidence suggests that reductions in the amplitude of persistent inward currents (PICs) in the motoneurons may be important....
Article
Passive heating has been therapeutically used to treat a range of health conditions. Further, this intervention presents as a potential exercise mimetic strategy showing acute and chronic effects on skeletal muscle adaptation and neuromuscular systems. This systematic review and meta-analysis aimed to synthesise the existing evidence on the effects...
Conference Paper
Full-text available
Background and aim: The mechanisms by which jaw clenching can enhance muscular force production are unclear, although facilitation of persistent inward currents (PICs) from brainstem derived serotonin could be involved. Serotonergic neurons project diffusely to motor pools, and previous research suggests that voluntary contraction of one muscle may...
Article
This study investigated whether modulation of corticospinal-motoneuronal excitability and/or synaptic transmission of the Ia afferent spinal reflex contributes to decreases in voluntary activation and muscular force after an acute bout of prolonged static muscle stretching. Fifteen males performed 5×60-s constant-torque stretches (15-s rest interva...
Article
Power training has been suggested to be effective in improving strength, power, and functional capacity in older adults. However, there is still a lack of systematic investigations reporting its effectiveness for muscle hypertrophy. Thus, this study investigated the effect of power training on muscle hypertrophy and compared its magnitude with trad...
Article
Introduction: There is a lack of definitive evidence supporting deficits in voluntary activation in participants with prior hamstring injury, moreover it remains unknown if spinal mechanisms contribute to suspected deficits. Purpose: To determine the effect of prior hamstring strain injury on knee flexor concentric and eccentric strength, volunt...
Article
Full-text available
Purpose We examined the effect of muscle stretching on the ability to produce rapid torque and the mechanisms underpinning the changes. Methods Eighteen men performed three conditions: (1) continuous stretch (1 set of 5 min), (2) intermittent stretch (5 sets of 1 min with 15-s inter-stretch interval), and (3) control. Isometric plantar flexor rate...
Article
Full-text available
Purpose The aim of the present study was to determine whether depression of maximal muscular force and neural drive subsequent to prolonged ( ≥ 60 s) passive muscle stretching is associated with altered corticospinal excitability or intracortical (GABAB-mediated) inhibition. Methods Fourteen healthy adult males were tested before and after 5 min (...
Article
Reduced levels of functional capacity in older adults are related to lower quality of life, frailty, and sarcopenia, and can increase risks of falling, fractures and hospitalisation. Resistance training is an effective method to attenuate age-related functional declines. Based on the findings that muscle power and explosive strength are strongly as...
Article
Full-text available
Multiple neuromuscular processes contribute to the loss of force production following repeated, high-intensity muscular efforts; however, the relative contribution of each process is unclear. In Experiment 1, 16 resistance trained men performed six sets of unilateral isometric plantar flexor contractions of the right leg (3 s contraction/2 s rest;...
Article
Barbosa, GM, Trajano, GS, Dantas, GAF, Silva, BR, and Vieira, WHB. Chronic effects of static and dynamic stretching on hamstrings eccentric strength and functional performance: A randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this study was to investigate the effect of static or dynamic stretching training prog...
Article
Introduction: Muscle force production is usually impaired in people with spinal cord injury (SCI). The use of high-intensity neuromuscular electrical stimulation (NMES) strength training can help promote metabolically active lean muscle mass and thus, increase muscle mass and improve physical health and quality of life (QoL). Nonetheless, NMES is...
Article
Full-text available
Resistance training is the most effective method to increase muscle mass. It has also been shown to promote many health benefits. Although it is deemed safe and of clinical relevance for treating and preventing a vast number of diseases, a time-efficient and minimal dose of exercise has been the focus of a great number of research studies. Similarl...
Article
Full-text available
Background: Neuromuscular electrical stimulation (NMES) is commonly used in skeletal muscles in people with spinal cord injury (SCI) with the aim of increasing muscle recruitment and thus muscle force production. NMES has been conventionally used in clinical practice as functional electrical stimulation (FES), using low levels of evoked force that...
Article
Full-text available
Adaptations to 6 weeks of supervised hamstring stretching training and its potential impact on symptoms of eccentric exercise-induced muscle damage (EIMD) were studied in 10 young, untrained men with limited hamstrings flexibility. Participants performed unilateral flexibility training (experimental leg; EL) on an isokinetic dynamometer while the c...
Article
Full-text available
Surface electromyography (sEMG) is a popular research tool in sport and rehabilitation sciences. Common study designs include the comparison of sEMG amplitudes collected from different muscles as participants perform various exercises and techniques under different loads. Based on such comparisons, researchers attempt to draw conclusions concerning...
Preprint
Surface electromyography (sEMG) is a popular research tool in sports and rehabilitation sciences. Common study designs include the comparison of sEMG amplitudes collected from different muscles as participants perform various exercises and techniques under different loads. Based on such comparisons, researchers attempt to draw conclusions concernin...
Article
Full-text available
It is well known that prolonged passive muscle stretch reduces maximal muscle force production. There is a growing body of evidence suggesting that adaptations occurring within the nervous system play a major role in this stretch-induced force reduction. This article reviews the existing literature, and some new evidence, regarding acute neurophysi...