Ing-Shiou Hwang

• Doctor of Philosophy
• Professor at National Cheng Kung University

Background Stroboscopic vision (SV), known for providing intermittent visual input, has been recently integrated into postural training to improve proprioceptive awareness. This research examined the impact of SV on cortico-posture coupling in older adults, along with the related changes in postural control throughout a spectrum of feedback and fee...

This study investigated cortical reorganization in older adults following short-term interactive balance training. Twenty participants aged 65–74 received training in stabilometer stance, visually aligning plate movement with a horizontal line on a monitor. Pre-test and post-test measured posture fluctuations and scalp EEG during stabilometer stanc...

Background Lateral epicondylitis is caused by overuse and manifests as pain, weakness, and difficulty with object manipulation. Platelet-rich plasma (PRP) and dextrose injections have shown promise in reducing pain and improving function. Hypothesis PRP is more effective for force precision control of the extensor carpi radialis brevis (ECRB) musc...

Neuromuscular electrical stimulation (NMES) combined with blood flow restriction (BFR) has garnered attention in rehabilitation for its ability to enhance muscle strength, despite the potential to accelerate training-related fatigue. This study examined changes in force scaling capacity immediately following combined NMES and BFR, focusing on motor...

This study aimed to investigate the hamstring activation in athletes with hamstring strain injuries in vertical jump tasks using an EMG time–frequency analysis. Fifteen injured athletes and 15 matched controls were recruited. The EMG signals of the lateral hamstring (LH) and medial hamstring (MH) were assessed during countermovement, squat, and dro...

Through phase-amplitude analysis, this study investigated how low-frequency postural fluctuations interact with high-frequency scalp electroencephalography (EEG) amplitudes, shedding light on age-related mechanic differences in balance control during uneven surface navigation. Twenty young (24.1 ± 1.9 years) and twenty older adults (66.2 ± 2.7 year...

Background Blood flow restriction (BFR) resistance training has demonstrated efficacy in promoting strength gains beneficial for rehabilitation. Yet, the distinct functional advantages of BFR strength training using high-load and low-load protocols remain unclear. This study explored the behavioral and neurophysiological mechanisms that explain the...

Objective This study explored the impact of one session of low-pressure leg blood flow restriction (BFR) during treadmill walking on dual-task performance in older adults using the neurovisceral integration model framework. Methods Twenty-seven older adults participated in 20-min treadmill sessions, either with BFR (100 mmHg cuff pressure on both...

Virtual error amplification (VEA) in visual feedback enhances attentive control over postural stability, although the neural mechanisms are still debated. This study investigated the distinct cortical control of unsteady stance in older adults using VEA through cross-frequency modulation of postural fluctuations and scalp EEG. Thirty-seven communit...

Purpose Despite its susceptibility to muscle fatigue, combined neuromuscular electrical stimulation (NMES) and blood flow restriction (BFR) is an effective regimen for managing muscle atrophy when traditional resistance exercises are not feasible. This study investigated the potential of low-level laser therapy (LLLT) in reducing muscle fatigue aft...

Background Task prioritization involves allocating brain resources in a dual-task scenario, but the mechanistic details of how prioritization strategies affect dual-task walking performance for Parkinson’s disease (PD) are little understood. Objective We investigated the performance benefits and corresponding neural signatures for people with PD d...

Objective: This study investigated the neuromuscular control of increasing and releasing force in patients with chronic lateral epicondylitis (CLE). Methods: Fifteen patients with CLE (10 males, 5 females, 46.5 ± 6.3 years) and fifteen healthy participants (9 males, 6 females, 45.3 ± 2.5 years) participated in this study. In addition to power grip...

This study aimed to investigate the hamstring onset time and recruitment level during jumping tasks in athletes with chronic hamstring strain injuries. Thirteen hamstring injured athletes and thirteen matched healthy athletes were recruited. Activation onset time and muscle recruitment (median frequency of the EMG) of the lateral hamstring (LH) and...

It is unclear how hamstring stiffness influences lower limb muscle activation during jump-landing mechanics. The study aimed to investigate the role of the hamstring stiffness on lower limb muscle recruitment during jumping manoeuvres. Thirty male athletes were recruited and allocated into high- and low-stiffness groups. Hamstring stiffness was det...

Visual feedback that reinforces accurate movements may motivate skill acquisition by promoting self-confidence. This study investigated neuromuscular adaptations to visuomotor training with visual feedback with virtual error reduction. Twenty-eight young adults (24.6 ± 1.6 years) were assigned to error reduction (ER) (n = 14) and control (n = 14) g...

Purpose: Despite early development of muscle fatigue, ischemic preconditioning is gaining popularity for strength training combined with low-load resistance exercise. This study investigated the effect of low-level laser (LLL) on post-contraction recovery with ischemic preconditioning. Methods: Forty healthy adults (22.9 ± 3.5 years) were alloca...

This study investigated behavioral and cortical mechanisms for short-term postural training with error amplification (EA) feedback in the elderly. Thirty-six elderly subjects (65.7 ± 2.2 years) were grouped (control and EA, n = 18) for training in stabilometer balance under visual guidance. During the training session (8 training rounds of 60 s in...

Due to basal ganglia dysfunction, short step length is a common gait impairment in Parkinson’s disease (PD), especially in a dual-task walking. Here, we use electroencephalography (EEG) functional connectivity to investigate neural mechanisms of a stride awareness strategy that could improve dual-task walking in PD. Eighteen individuals with PD who...

Various infarct sizes induced by middle cerebral artery occlusion (MCAO) generate inconsistent outcomes for stroke preclinical study. Monitoring cerebral hemodynamics may help to verify the outcome of MCAO. The aim of this study was to investigate the changes in brain tissue optical properties by frequency-domain near-infrared spectroscopy (FD-NIRS...

Background: Stroboscopic vision (SV), intermittent visual blocking, has recently been incorporated into postural training in rehabilitation. This study investigated interactions of postural fluctuation dynamics and cortical processing for the elderly during stabilometer stance with SV. Methods: Thirty-five healthy elderly maintained an upright stan...

Improving lower extremity sports performance may contribute to punching performance in boxers. We compared the effects of two typical boxing routines for developing lower extremity sports performance and subsequent punching performance. Twenty-four high school amateur boxers between the ages of 12 and 18 performed training at least 3 days per week....

Visual processing of complex character configurations is especially challenging for Chinese-speaking children with dyslexia (CSCD). The purpose of this study was to compare the effects of visual occlusion on postural control between dyslexic and non-dyslexic Chinese-speaking children by examining their visual-perceptual capacity and movement coordi...

Appropriate attentional resource allocation could minimize exaggerated dual-task interference due to basal ganglia dysfunction in Parkinson’s disease (PD). Here, we assessed the electroencephalography (EEG) functional connectivity to investigate how task prioritization affected posture-motor dual-tasks in PD. Sixteen early-stage PD patients and 16...

Background Error amplification (EA), virtually magnify task errors in visual feedback, is a potential neurocognitive approach to facilitate motor performance. With regional activities and inter-regional connectivity of electroencephalography (EEG), this study investigated underlying cortical mechanisms associated with improvement of postural balanc...

Background Proximal tibiofibular joint (PTFJ) instability is uncommon, resulting from violent twisting motions of the flexed knee during sport activities. No known image variables functionally relate the degrees of PTFJ instability. Objective This study used ultrasound imaging to quantify the discrimination threshold for PTFJ instability and relev...

Older adults with degenerative declines in sensory systems depend strongly on visual input for postural control. By connecting advanced neural imaging and a postural control model, this study investigated the visual effect on the brain functional network that regulates feedback and feedforward processes of the postural system in older adults under...

Healthy people use a keyboard and mouse as standard input devices for controlling a computer. However, these input devices are usually not suitable for people with severe physical disabilities. This study aims to design and implement a suitable and reliable human–computer interactive (HCI) interface for disabled users by integrating both eye tracki...

Skill transfer from trained balance exercises is critical to reduce the rate of falls in older adults, who rely more on vision to control postural responses due to age-dependent sensory reweighting. With an electroencephalography (EEG) minimum spanning tree (MST) structure, the purpose of this study was to compare the organization of supraspinal ne...

Joint constraint could limit the available degrees of freedom in a kinematic chain for maintaining postural stability. This study investigated adaptive changes in postural synergy due to bracing of bilateral knee joints, usually thought to have a trifling impact on upright stance. Twenty-four young adults were requested to maintain balance on a sta...

This study investigated how visual feedback of virtual error reduction (ER) modified the visuomotor performance of older adults with limited attentional capacity. Error structures of young and older adults during birhythmic force tracking were contrasted when the visualized error size was exact or half of the actual size. As compared with full-size...

PurposeThis study investigated fatigue-related modulation of common neural inputs to motor units (MUs) under 5 Hz, which determines force precision control.Methods Twenty-seven adults performed a sequence of fatiguing contractions. The participants were assessed with a static isometric index abduction at 20% maximal voluntary contraction in the pre...

PurposeBlood flow restriction (BFR) is an innovation in fitness to train muscles with low loads at low oxygen levels. Low-level laser therapy (LLLT) is a bio-energetic approach to alleviate muscle fatigue during resistance training. This study investigated the immediate effect of LLLT pre-conditioning on BFR that accelerates muscle fatigue due to i...

This study contrasted the stochastic force component between young and older adults, who performed pursuit tracking/compensatory tracking by exerting in-phase/antiphase forces to match a sinusoidal target. Tracking force was decomposed into the force component containing the target frequency and the nontarget force fluctuations (stochastic componen...

Although force steadiness varies with visuospatial information, accountable motor unit (MU) behaviors are not fully understood. This study investigated the modulation of MU discharges and force-discharge relation due to variations in the spatial resolution of visual feedback, with a particular focus on discharge variability among MUs. Fourteen youn...

Although error amplification (EA) feedback has been shown to improve performance on visuomotor tasks, the challenge of EA is that it concurrently magnifies task-irrelevant information that may impair visuomotor control. The purpose of this study was to improve the force control in a static task by preclusion of high-oscillatory components in EA fee...

Objectives: Restricted central processing in older adults prevents optimization of a dual task with a flexible prioritization strategy. This study investigated the neural mechanisms of task-priority in young and older adults when performing a posture-motor dual-task. Method: Sixteen healthy young and 16 older adults performed a force-matching ta...

Joint constraint interferes with the coordinative structure in joint movements used to optimize postural stability. This study aimed to investigate changes in postural synergy when the ankle joints were bilaterally braced during a stabilometer stance. Twenty-four young adults stood on a stabilometer plate while wearing a pair of ankle-foot orthoses...

Objective: To examine the task prioritization effects on postural-suprapostural dual task performance in patients with early-stage Parkinson's disease (PD) without clinical observed postural symptoms. Design: Cross-sectional study. Participants performed a force-matching task while standing on a mobile-platform, and were instructed to focus thei...

This study investigated age-related changes in behavioral and neural complexity for a polyrhythmic movement, which appeared to be an exception to the loss of complexity hypothesis. Young (n = 15; age = 24.2 years) and older (15; 68.1 years) adults performed low-level force-tracking with isometric index abduction to couple a compound sinusoidal targ...

Error amplification (EA) feedback is a promising approach to advance visuomotor skill. As error detection and visuomotor processing at short time scales decline with age, this study examined whether older adults could benefit from EA feedback that included higher-frequency information to guide a force-tracking task. Fourteen young and 14 older adul...

Visual feedback that provides error information is critical to task quality and motor adjustments. This study investigated how the size of perceived errors via visual feedback affected rate control and force gradation strategy of a designate force task. Fourteen young adults coupled force exertions to a compound sinusoidal signal (0.2 Hz and 0.5 Hz...

The aged brain may not make good use of central resources, so dual task performance may be degraded. From the brain connectome perspective, this study investigated dual task deficits of older adults that lead to task failure of a suprapostural motor task with increasing postural destabilization. Twelve younger (mean age: 25.3 years) and 12 older (m...

The detection of error information is an essential prerequisite of a feedback-based movement. This study investigated the differential behavior and neurophysiological mechanisms of a cyclic force-tracking task using error-reducing and error-enhancing feedback. The discharge patterns of a relatively large number of motor units (MUs) were assessed wi...

Discharge patterns from a population of motor units (MUs) were estimated with multi-channel surface electromyogram and signal processing techniques to investigate parametric differences in low-frequency force fluctuations, MU discharges, and force-discharge relation during static force-tracking with varying sizes of execution error presented via vi...

Increase in postural-demand resources does not necessarily degrade a concurrent motor task, according to the adaptive resource-sharing hypothesis of postural-suprapostural dual-tasking. This study investigated how brain networks are organized to optimize a suprapostural motor task when the postural load increases and shifts postural control into a...

With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a si...

Dual-task performance is strongly affected by the direction of attentional focus. This study investigated neural control of a postural-suprapostural procedure when postural focus strategy varied. Twelve adults concurrently conducted force-matching and maintained stabilometer stance with visual feedback on ankle movement (visual internal focus, VIF)...

A fundamental approach for resolving motor deficits in patients suffering from various neurological diseases is to improve the impaired cortical function through the modulation of plasticity. In order to advance clinical practice in this regard, it is necessary to better understand the interactions that occur between functional neuromuscular activi...

Continuous force output containing numerous intermittent force pulses is not completely smooth. By characterizing force fluctuation properties and force pulse metrics, this study investigated adaptive changes in trajectory control, both force-generating capacity and force fluctuations, as fatigue progresses. Sixteen healthy subjects (20-24 years ol...

For skill advancement, motor variability must be optimized based on target information during practice sessions. This study investigated structural changes in kinematic variability by characterizing submovement dynamics and muscular oscillations after practice with visuomotor tracking under different target conditions. Thirty-six participants were...

Movement characteristics can be coded in the single neurons or in the summed activity of neural populations. However, whether neural oscillations are conditional to the frequency demand and task quality of rhythmic force regulation is still unclear. This study was undertaken to investigate EEG dynamics and behavior correlates during force-tracking...

Force intermittency is one of the major causes of motor variability. Focusing on the dynamics of force intermittency, this study was undertaken to investigate how force trajectory is fine-tuned for static and dynamic force-tracking of a comparable physical load. Twenty-two healthy adults performed two unilateral resistance protocols (static force-t...

This study investigated how frequency demand and motion feedback influenced composite ocular movements and eye-hand synergy during manual tracking. Fourteen volunteers conducted slow and fast force-tracking in which targets were displayed in either line-mode or wave-mode to guide manual tracking with target movement of direct position or velocity n...

Visual feedback and non-visual information play different roles in tracking of an external target. This study explored the respective roles of the visual and non-visual information in eleven healthy volunteers who coupled the manual cursor to a rhythmically moving target of 0.5 Hz under three sensorimotor conditions: eye-alone tracking (EA), eye-ha...

The study investigated the destabilization effect on multi-segment physiological tremors and coordinative control for a postural-suprapostural task under different stance conditions. Twenty volunteers executed postural pointing from a level surface and a seesaw balance board; meanwhile, physiological tremors of the whole postural system and fluctua...

To examine the effect of reaching in different directions on postural adjustment in children with diplegic cerebral palsy (CP), and to examine the relationship between hand reach performance and postural adjustment, and between postural control ability and postural adjustment. Cross-sectional study. A movement science laboratory at a medical univer...

Motor overflow (MO) is an involuntary muscle activation associated with strenuous contralateral movement and may become manifested after stroke. The study was undertaken to investigate physiological correlation underlying atypical directional effect of joint movement on post-stroke MO in the affected upper limb. Thirty patients with unilateral post...

This study was undertaken to investigate the reciprocity effect between postural and suprapostural performances and its underlying neural mechanisms wherein subjects executed a perceptual-motor suprapostural task and maintained steady upright postures. Fourteen healthy individuals conducted force-matching maneuvers (static vs. dynamic) under two st...

The study was undertaken to investigate the contralateral overflow effect on physiological tremors in pianists and nonmusicians. Group differences in cross modulation on underlying finger fractionated movement were characterized. Physiological tremors of the right index, middle, ring, and little fingers were recorded in 12 right-handed pianists and...

Physiological tremors within a limb are coupled, whereas between-limb tremors are thought to oscillate independently for a healthy subject. This study was undertaken to reinvestigate bilateral tremor relations and intra-limb tremor dynamics for a two-limb task after exhausting a single joint. Fifteen volunteers conducted prolonged tracking with the...

This study was undertaken to investigate the effect of low-level loading on digit tracking and the associated physiological tremors in the moving and the stationary digits. Sixteen healthy adults conducted positional tracking with the middle finger under the loaded and unloaded conditions; meanwhile, trajectory of the middle finger, electromyograph...

PURPOSE:: The study was undertaken to investigate the contralateral overflow effect on physiological tremors in pianists and non-musicians. Group differences in cross modulation on underlying finger fractionated movement were characterized. METHODS:: Physiological tremors of the right index, middle, ring, and little fingers were recorded in 12 righ...

To compare stance control between children with sensory modulation disorder (SMD) and typically developing children in various visual and somatosensory conditions. Thirty-one children participated in this study, including 17 children with SMD and 14 matched typically developing children. The Sensory Profile was used to screen for sensory modulation...

Progressive changes in the muscle tone and stretch reflex after spinal cord injury (SCI) provide insight into the time-course development of spasticity. This study quantified the time-course changes of hypertonia for rats following SCI of T8 hemisection. A miniature manual stretching device measured the reactive torque via a pair of pressure sensin...

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique that is capable of producing after-effects outlasting the stimulation for minutes to more than an hour. Varied paradigms and targets of the stimulation may produce different brain modulations corresponding to the changes of specific cortical plasticity. Conventional low...

The objective of this study was to investigate the reciprocal influences of stance pattern (bilateral stance vs. unilateral stance) and thumb-index precision grip task (static target vs. dynamic target) on postural-suprapostural tasks by manipulating task-load. Fifteen healthy volunteers participated in four postural-suprapostural tasks, including...

Through examining tremor dynamics, the study sought to investigate the effects of load characteristics upon control strategies in patients with Parkinson's disease (PD) during postural holding. Eleven untreated patients and eleven healthy adults conducted a static pointing task with an outstretched arm, with a manipulated load of 100 g on the index...

In light of the interplay among physiological finger tremors, this study was undertaken to investigate the transfer effect of fatigue on coordinative strategies of multiple fingers. Fourteen volunteers performed prolonged position tracking with a loaded middle finger while measures of neuromuscular function, including electromyographic activities o...

This study contrasted the effects of load characteristics on coordinative strategies between postural holding and position tracking. Fifteen healthy adults conducted postural holding and sinusoidal tracking with the index finger while manipulated loads (0, 50, and 100 g) were superimposed on an outstretched arm. Oscillatory activities in the upper...

A postural tremor appears whenever someone attempts to maintain a steady position against gravity. We examined the postural tremor that occurred while air pistol shooters were taking aim so as to compare the coordinative control of the shooters and to identify the features critical to successful shooting. Ten elite and ten pre-elite athletes partic...

The objective of this study was to examine the changes in H reflex sensitivity after neuromuscular fatigue associated with fluctuations of the M wave. In the maximal and submaximal voluntary contraction (MVC and SMVC) paradigms, subjects performed voluntary plantarflexion at 100% MVC and 40% MVC respectively until the limit of torque maintenance wa...

The objective of the study was to investigate the interplay between involuntary tremulous activities and task performance under volitional control for patients with Parkinson's disease (PD) during position tracking. A volunteer sample of nine untreated patients and nine age-matched healthy subjects participated in this study. They performed a sinus...

The quiet stance is a complicated motor act requiring sophisticated sensorimotor integration to balance an artificial inverted pendulum with the ankle musculature. The objective of this study was to characterize the effects of stance pattern (bilateral stance vs. unilateral stance) and directional influence of light finger touch (medial-lateral vs....

In reference to electromyographic measurement, the study was conducted to reassess differences in the behavior of fatigue-related neuromuscular function between young and elderly humans with limb acceleration (LA). Fourteen young and fourteen elderly subjects performed sustained index abduction at 75% of their maximal voluntary contractions (MVC) u...

5-1 Advantages and Disadvantages of Robotics for Rehabilitation of Stroke Patients One may find that robotics provides an integral solution to the treatments and objective assessments of some neurological diseases such as stroke. The robots can perform repeated treatment protocols without the need of continuous involvement of therapists. A robot ca...

Forty-eight children, aged 4-6 years, walked while performing or not performing an easy or difficult concurrent motor task (carrying a tray with or without marbles on it) or cognitive task (repeating a series of digits forwards or backwards). The temporal-distance gait parameters were measured using a GAITRite electronic walkway system. Dual-task c...

The aim of the study was to examine spectral features of the mechanomyogram (MMG) and electromyogram (EMG) during static and load-varying isometric dorsiflexion to characterize force control strategies of the tibialis anterior. Twelve healthy subjects performed two motor tasks including 1) four exertion levels of static isometric dorsiflexion and 2...

In light of the interplay between limb oscillatory outputs and the outcome performance of movement effectors, this study was undertaken to investigate neuromotor control in the upper limb during position tracking and posture holding. Sixteen volunteers conducted a postural pointing task and two index tracking maneuvers at 0.3 and 0.6 Hz with an out...

As the H reflex remains unable to assess mechanical changes intrinsic to a muscle, the aim of this study was to modify the H reflex techniques and to characterize the neural and mechanical components of muscle spasticity, relating the two components to clinical observations. Thirty-four patients featuring either a spinal-cord lesion (n=15) or strok...

The intensity and spatial representation of electromyographical (EMG) activity were examined to characterize the effects of limb dominance and movement direction upon global synkinesis (GS). Twenty-two healthy young subjects (11 men, 11 women) with a mean age of 24.7 years participated in this study. Three trials of EMG activities from eight primar...

The study was conducted to contrast exertion-dependent changes in electromyography (EMG), force fluctuation (FF), and limb acceleration (LA) during isometric contraction to attain a versatile picture of muscle fatigue. Fifteen volunteers performed sustained index abduction at 25 and 75% maximal voluntary contractions (MVC) until failure at the task...

An experiment was conducted to compare the effects of bilateral and unilateral stance on postural fluctuations and intralimb coordination during active balance control. Fifteen participants stood bilaterally and unilaterally while conducting a pointing task with an outstretched arm. Excursion of center of foot pressure (CoP) and limb movements were...

To investigate change in coordinative strategies due to wrist immobilization and index loading, postural tremors from the index, hand, and forearm were recorded during different postural holding tasks. The wrist joint was immobilized with a thermoplastic splint in the constrained condition, and a copper mass of 100 grams was applied to the index fi...

This study investigated exertion-dependent motor overflow among healthy adults when they performed isometric tasks with contralateral joints in different task directions. Twenty healthy adults (10 males and 10 females, mean age = 26.2 yrs) were instructed to complete a set of isometric contractions of various force vectors with the shoulder, elbow,...

The goal of this study was to design a robot system for assisting in the rehabilitation of patients with neuromuscular disorders by performing various facilitation movements. The robot should be able to guide patient's wrist to move along planned linear or circular trajectories. A hybrid position/force controller incorporating fuzzy logic was devel...

Global synkinesis (GS), or motor irradiation, is an involuntary movement associated with the coactivation of numerous muscles in one limb when the opposite limb is active. The electromyographic (EMG) patterns of people with stroke and people who were healthy were analyzed to characterize GS development in relation to joint involvement and to attemp...

Although both starting position and stretching velocity play an important role in reflex response, their interaction with stretch reflexes has not been thoroughly investigated. This study examined the interaction effect of starting position and stretching velocity on the reflex threshold angle (RTA) of the stretch reflex in the soleus muscle of nor...

The objective of the research was to examine the effects of loading and posture on motoneuronal excitability of the triceps surae (TS) for patients with hemiplegia. Twelve healthy subjects and 12 patient subjects with post-stroke hemiparesis (onset period: 3-60 months) were enrolled in this study. The subjects were instructed to remain in quiet sit...

The purpose of this study was to investigate the dependence of the surface EMG and varied internal effort due to different joint positions, and its muscle control strategies. Ten healthy subjects performed a fixed level (40% MVC measured in the neutral position) of isometric dorsiflexion and plantarflexion contraction in the ankle neutral, dorsifle...

This study quantified the performance variability and effect of rail support on the ankle joint for normal and hemiparetic subjects during treadmill walking. Muscle activities of the anterior tibialis (TA) and medial gastrocnemius (MG) from six hemiparetic patients and 14 healthy subjects were assessed with EMG linear envelope and variance ratio of...

Inter-trial variation in soleus H reflex amplitude for different effort modes, elicited at different test-stimulus intensities, was studied in fifteen healthy subjects. Regardless of test-stimulus intensity, weak isometric plantarflexion and dorsiflexion at 20% of maximum voluntary contraction caused significant potentiation and depression of the H...

As variations in the amplitude of H reflex potentials can be influenced by changes in muscle length, motoneuronal excitability in terms of H reflex during free movement has long been argued. With the maximal M response controlled, the present study compared several H reflex parameters in order to assess motoneuronal excitability of the resting sole...

To investigate the effects of joint position and effort level of antagonist contraction on reciprocal inhibition, experiments with 15 healthy volunteers were performed to compare the changes of standardized soleus H reflex during dorsiflexion contraction (0%, 25%, 50%, 75% maximal voluntary contraction [MVC] associated with different ankle position...

To quantify velocity dependent and position related properties of increased muscle tone measured during a constant velocity stretch. Elbow flexors were vertically stretched under four different velocities (40, 80, 120, and 160 degrees /s) through a 75 degrees range of motion in 12 patients with hemiparesis, 16 with parkinsonism, and 12 normal contr...

Synergy generally refers to the coordinated action of several motor elements to produce a specific motor task, either intentionally or automatically. One example is motor irradiation, a sudden spread of synergistic muscular coactivation resulting from a forceful single joint movement. To investigate this type of synergy pattern, a quantitative EMG...