Andrew J. T. Stevenson

Andrew J. T. Stevenson
Aalborg University · Department of Health Science and Technology

Ph.D. (Aalborg University), M.Sc. (University of British Columbia), B.Sc. (University of Auckland)

About

43
Publications
7,735
Reads
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396
Citations
Education
September 2011 - August 2015
Aalborg University
Field of study
  • Neurophysiology
September 2009 - July 2011
February 2005 - June 2008
University of Auckland
Field of study
  • Sport & Exercise Science, Psychology

Publications

Publications (43)
Article
Brain-computer interfaces (BCIs) have the potential to improve functionality in chronic stoke patients when applied over a large number of sessions. Here, we evaluate the effect and the underlying mechanisms of three BCI training sessions in a double-blind-sham-controlled design. The applied BCI is based on Hebbian principles of associativity that...
Article
Full-text available
Robot-mediated therapy can help improve walking ability in patients following injuries to the central nervous system. However, the efficacy of this treatment varies between patients, and evidence for the mechanisms underlying functional improvements in humans is poor, particularly in terms of neural changes in the spinal cord. Here, we review the r...
Article
Full-text available
The rapid release of prepared movements by a loud acoustic stimulus capable of eliciting a startle response has been termed the StartReact effect (Valls-Solé et al., 1999), and premotor reaction times (PMTs) of <70 ms are often observed. Two explanations have been given for these short latency responses. The subcortical storage and triggering hypot...
Article
A strong coordination between the two legs is important for maintaining a symmetric gait pattern and adapting to changes in the external environment. In humans as well as animals, receptors arising from the quadriceps muscle group influence the activation of ipsilateral muscles. Moreover, strong contralateral spinal connections arising from quadric...
Article
Full-text available
Recent studies have shown that afferents arising from muscle receptors located on one side can affect the activity of muscles on the contralateral side. In animal preparations, evidence supports that afferent pathways originating from one limb converge onto interneurons mediating disynaptic reciprocal Ia inhibition of the opposite limb. This study...
Article
Full-text available
Introduction Falls among older adults are most frequently caused by slips and trips and can have devastating consequences. Perturbation-based balance training (PBT) have recently shown promising fall preventive effects after even small training dosages. However, the fall preventive effects of PBT delivered on a treadmill are still unknown. Therefor...
Article
Full-text available
Conventional transcutaneous electrical nerve stimulation (TENS) has been reported to effectively alleviate chronic pain, including phantom limb pain (PLP). Recently, literature has focused on modulated TENS patterns, such as pulse width modulation (PWM) and burst modulation (BM), as alternatives to conventional, non-modulated (NM) sensory neurostim...
Article
Full-text available
Transcranial magnetic stimulation (TMS) can be used to study excitability of corticospinal neurons in human motor cortex. It is currently not fully elucidated if corticospinal neurons in the hand vs. leg representation show the same or different regulation of their excitability by GABAAergic and glutamatergic interneuronal circuitry. Using a paired...
Article
ter Beek, F, Jokumsen, PS, Sloth, BN, Thomas Stevenson, AJ, and Larsen, RG. Ischemic preconditioning attenuates rating of perceived exertion but does not improve maximal oxygen consumption or maximal power output. J Strength Cond Res XX(X): 000-000, 2020-Brief consecutive periods of limb ischemia and reperfusion, known as ischemic preconditioning (...
Conference Paper
Full-text available
Knowledge on the behaviour and control of human voluntary stereotyped rhythmic movement has relevance for sick, injured, and healthy individuals. In the present study, unilateral finger tapping was applied as a model of such a type of movement. We studied the phenomenon of repeated bout rate enhancement, which covers an increase of the freely chose...
Article
These hypotheses were tested: (1) Freely chosen frequency in unilateral index finger tapping is correlated between the two index fingers, and (2) A 3-min bout of unilateral index finger tapping followed by 10 min rest results in an increase of the freely chosen tapping frequency performed by the contralateral index finger in a second bout. Thirty-t...
Conference Paper
Brain-computer interfaces have increasingly found applications within the rehabilitation of lost motor function in stroke patients. Most studies have targeted upper limb muscles and used sensorimotor rhythms as the control signal. In a series of studies, we have introduced an associative BCI modeled on known theories of memory and learning that imp...
Conference Paper
Artificial activation of peripheral afferent fibers, with the resulting sensory feedback timed to arrive at the peak negativity of the movement-related cortical potential, induces significant increases in the excitability of cortical projections to the target muscle in healthy individuals and chronic stroke patients. In the currently ongoing study,...
Article
Full-text available
Purpose Delayed onset muscle soreness (DOMS) has been shown to induce changes in muscle activity during walking. The aim of this study was to elucidate whether DOMS also affects interlimb communication during walking by investigating its effect on short-latency crossed responses (SLCRs). Methods SLCRs were elicited in two recording sessions by ele...
Article
Objective Adjuvant protocols devised to enhance motor recovery in subacute stroke patients have failed to show benefits with respect to classic therapeutic interventions. Here we evaluate the efficacy of a novel brain‐state dependent intervention based on known mechanisms of memory and learning, that is integrated as part of the weekly rehabilitati...
Article
Declines in motor function with advancing age have been attributed to changes occurring at all levels of the neuromuscular system. However, the impact of aging on the control of muscle force by spinal motor neurons is not yet understood. In this study on 20 individuals aged between 24 and 75 yr (13 men, 7 women), we investigated the common synaptic...
Conference Paper
INTRODUCTION: Five sessions of remote ischemic preconditioning (RIPC) can enhance gross motor learning (Cherry-Allen et al., 2015, J Neurophysiol, 113(10); Cherry-Allen et al., 2017, J Motor Behav, 49(3)). The aim of this study was to investigate the effect of one session of RIPC on fine motor skill learning. A single session of high intensity exer...
Chapter
An efficient innovative Brain-Computer-Interface system that empowers chronic stroke patients to control an artificial activation of their lower limb muscle through task specific motor intent has been tested in the past. In the current study it was applied to acute stroke patients. The system consists in detecting the movement-related cortical pote...
Chapter
In humans, short-latency crossed spinal inhibitory reflexes are elicited in the contralateral soleus (cSOL) muscle following stimulation of the ipsilateral posterior tibial nerve (iPTN). To date, the spinal interneurons mediating the cSOL inhibition are unknown. This study investigated whether the Ia inhibitory interneurons in the disynaptic recipr...
Conference Paper
Full-text available
Background Ipsilateral knee (iKnee) joint rotations in seated humans elicit short-latency crossed spinal reflexes in the contralateral biceps femoris (cBF) muscle (Stevenson et al., JPhysiol., 2015). The short-latency cBF reflexes were inhibitory following iKnee extension perturbations, and facilitatory following flexion perturbations. Due to the o...
Conference Paper
Full-text available
Background Paired-pulse transcranial magnetic stimulation (TMS) combines two single pulses, a conditioning pulse (S1) and a testing pulse (S2), with a given inter-stimulus interval (ISI). In upper limb muscles, the interaction between short interval intracortical inhibition (SICI) and facilitation (SICF) is thoroughly examined (Ilić et al., JPhysio...
Conference Paper
Introduction One of the sites that can be affected by motor training is the primary motor cortex (1,2,3), but sometimes learning a movement is only the beginning of a training regime. The effect of resistance training on corticospinal function is still unclear, and previous studies have often focused on minor distal muscles (4,5,6). Therefore, the...
Article
Full-text available
Paired associative stimulation (PAS) protocols induce plastic changes within the motor cortex. The objectives of this study were to investigate PAS effects targeting the tibialis anterior (TA) muscle using a biphasic transcranial magnetic stimulation (TMS) pulse form and, to determine whether a reduced intensity of this pulse would lead to signific...
Conference Paper
Full-text available
Interlimb reflexes play an important role in human walking, such as when dynamic stability is threatened by external perturbations or changes in the walking surface. For example, we have previously shown that interlimb reflexes in the contralateral biceps femoris (cBF) following ipsilateral knee (iKnee) extension rotations during walking contribute...
Conference Paper
Full-text available
Performing repeated motor tasks during a volleyball, basketball, or soccer game can lead to muscular fatigue, inducing a decrease in the capacity of a muscle to generate force, changes in motor coordination, and an alteration in motor performance. These changes have been attributed to an elevated risk of musculoskeletal injury. Little is known abou...
Thesis
Full-text available
A continual coordination between the two legs is necessary for maintaining a symmetric walking pattern and adapting to changes in the external environment. Recent evidence in animals and humans suggests that spinal interneuronal circuits under supraspinal control may mediate communication between the lower limbs. The overall objective of the presen...
Article
Key points: The present study is the first to show short-latency crossed-spinal reflexes in the human upper leg muscles following mechanical rotations to the ipsilateral knee (iKnee) joint. The short-latency reflex in the contralateral biceps femoris (cBF) was inhibitory following iKnee extension perturbations, and facilitatory following iKnee fle...
Conference Paper
Full-text available
Ipsilateral knee (iKnee) joint rotations in seated humans elicit short-latency crossed spinal reflexes in the contralateral biceps femoris (cBF) muscle (Stevenson et al., 2012). The short-latency cBF reflexes were inhibitory following iKnee extension perturbations, and facilitatory following flexion perturbations. Due to the onset latency (45 ms),...
Article
Interlimb reflexes play an important role in human walking, particularly when dynamic stability is threatened by external perturbations or changes in the walking surface. Interlimb reflexes have recently been demonstrated in the contralateral biceps femoris (cBF) following knee joint rotations applied to the ipsilateral leg (iKnee) during the late...
Conference Paper
Full-text available
Short-latency crossed spinal reflexes have recently been demonstrated in the contralateral biceps femoris (cBF) muscle following ipsilateral knee joint rotations during sitting in humans (Stevenson et al., SfN, New Orleans, 2012). The short-latency cBF reflexes were inhibitory following knee extension rotations, and facilitatory following knee flex...
Chapter
In this study we examined the functionality of the contralateral biceps femoris (cBF) reflex response following ipsilateral knee extension joint rotations during the late stance phase of the gait cycle [1]. Stevenson et al. [1] proposed that the cBF reflex acts to slow the forward progression of the body in order to maintain dynamic equilibrium dur...
Conference Paper
Full-text available
Contralateral reflex responses have recently been demonstrated in the knee flexors during the late stance phase of human gait (Stevenson et al., 19th ISEK congress, Australia, 2012). Following unexpected extension perturbations to the ipsilateral knee joint at 50% of the gait cycle, the contralateral biceps femoris (cBF) muscle was strongly facilit...
Conference Paper
Full-text available
Contralateral reflex responses have recently been demonstrated in the knee flexors during the late stance phase of human gait (Stevenson et al., 19th ISEK congress, Australia, 2012). Following unexpected extension perturbations to the ipsilateral knee joint at 50% of the gait cycle, the contralateral biceps femoris (cBF) muscle was strongly facilit...
Conference Paper
Introduction: Interlimb coordination is essential to the smooth organization of human movement, such as during walking. Stubbs et al. (2009, 2011) recently found that electrical stimulation to the tibial nerve of the ipsilateral leg elicited a short-latency (onset 37-41 ms) crossed spinal inhibition response in the soleus muscle of the contralatera...
Conference Paper
Background: Short-latency crossed spinal inhibitory responses have recently been demonstrated in the human soleus muscle (Stubbs & Mrachacz-Kersting 2009). Following contralateral posterior tibial nerve (PTN) stimulation, the ipsilateral soleus is inhibited at a latency of about 40-45 ms. This inhibition likely contributes to interlimb coordination...
Conference Paper
For several decades, much attention has been given to units of linguistic representation for speech production. Different theories have proposed different levels of linguistic representation and different sizes of units in speech production. The present study investigates the planning of these units, and in particular, whether these units – includi...
Conference Paper
The goal of this study was to examine the subcortical storage and triggering hypothesis put forward by Valls-Solé et al. (1999) and Carlsen et al. (2004). This hypothesis suggests that voluntary movements that can be prepared in advance of an imperative stimulus (IS) are stored and triggered from subcortical areas without cortical involvement by a...
Conference Paper
Speech production like other limb movements relies on both feed‐forward and feedback mechanisms. Use of a startling auditory stimulus (>90 dB) has been shown to trigger fast, accurate feed‐forward performances in upper limb movements prior to access to feedback information [Valls‐Solé et al. (1999), J. Physiol. 516: 931–938; Carlsen et al. (2004),...
Conference Paper
Full-text available
Studies have reported increased activity in motor cortical areas during emotional processing. Additionally, exposure to unpleasant emotional images, as compared with pleasant and neutral images, has been shown to accelerate premotor reaction times (PRT) of upper limb ballistic extension movements. In the present study, we examined the effects of a...

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