Yi-Ching Chen

• Durham 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...

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...

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...

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...

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...

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...

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...

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...

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 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...

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...

The objective of this study was to demonstrate the diversity of urodynamic findings and temporal effects on bladder dysfunction in diabetes as well as to evaluate the predisposing factors that attenuate the storage and voiding function of diabetic women. In this prospective study, 181 women with type 2 diabetes mellitus (DM) and lower urinary tract...

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...

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...

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...

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 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...

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,...

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...

Prevalence studies show that nocturia is a very common condition, affecting older age groups in particular. In this study, we evaluate (1) the community-based prevalence of nocturia and its associated overactive bladder according to the patient's perception and disturbance to sleep and (2) whether age or menopausal (MP) transition has a greater eff...

Tissue ischemia-hypoxia can activate the calpain proteolytic system. Mechanical trauma to the upper vaginal wall and pelvic floor could compromise vascular perfusion and could also result in calpain expression. The aims of this investigation were to assess the expression messenger RNA and proteins for m-calpain and micro-calpain in the vaginal wall...

Anal incontinence and constipation are not only physically and psychologically disabling symptoms but also a significant social and public health problem. The epidemiology of anal incontinence and constipation from community-bases remains largely unknown, especially in Asian women. This study is a continuation of a previous survey taken on the epid...

To evaluate whether the increasing occurrence of urinary and voiding dysfunction is independently influenced by the transition from pre- to postmenopause or by the interactive and additive effects of age-associated changes in bladder and urethral function. Of the 1,584 women randomly sampled from a community-based health population, 1,253 (79.1%) w...

We randomly sampled a community-based, healthy population to evaluate the prevalence and correlation of urinary incontinence and overactive bladder. We also assessed the influences of these conditions on quality of life and associated risk factors. Of the 1,581 women sampled (2.92% of registered female residents aged 20 years and older), 1,253 (79....