Increasing Visual Biofeedback Scale Changes Postural Control Complexity.

Visual biofeedback (vFB) during quiet stance has been shown to improve postural control. While this improvement has been quantified by a reduction in the center of pressure (COP) sway, the effect on COP complexity remains unexplored. As such, 20 young adults (12 females; aged 23.

Investigating motor preparation in synchronous hand and foot movements under reactive vs. predictive control.

Synchronizing hand and foot movements under reactive versus predictive control results in differential timing structures between the responses. Under reactive control, where the movement is externally triggered, the electromyographic (EMG) responses are synchronized, resulting in the hand displacement preceding the foot. Under predictive control, where the movement is self-paced, the motor commands are organized such that the displacement onset occurs relatively synchronously, requiring the EMG onset of the foot to precede that of the hand.

Involvement of the prefrontal cortex in motor sequence learning: A functional near-infrared spectroscopy (fNIRS) study.

Our previous functional near-infrared spectroscopy (fNIRS) study on motor sequence learning (Polskaia et al., 2020) did not detect the same decrease in activity in the left dorsolateral prefrontal cortex (DLPFC) associated with movement automaticity, as reported by Wu et al. (2004).

The impact of eye movement on postural control depends on the type of oculomotor behavior and the visual task.

Recent evidence suggests that performing a task inducing saccades will improve stability when compared to static fixation. However, they assume the linearity of postural control by only interpreting the area of displacement and/or the velocity of sway. Conversely, non-linear measures could bring a complementary understanding of postural control.

Neural Correlates of Dual-Task Processing following Motor Sequence Learning: A Functional Near-Infrared Spectroscopy (fNIRS) Study.

The current study used functional near-infrared spectroscopy (fNIRS) to examine cerebral oxygenation changes in the prefrontal cortex (PFC) associated with dual-task processing before and after motor sequence learning. Participants performed self-initiated sequential finger movements that were 4 and 12 units in length with a visual letter-counting task. After practice, dual-task sequence-4 performance revealed decreased activity in the right dorsolateral PFC, medial PFC, and orbitofrontal cortex.

Hemodynamic responses of quiet standing simultaneously performed with different cognitive loads in older adults.

Postural control decrements with advancing age have been largely identified in the literature. Dual-task paradigms have been utilized to increase older adults' stability in order to direct the attention towards the completion of a secondary task, leaving the automatic motor control processes to modulate posture unconstrained. To the extent that older adults allocate greater attentional resources to maintain an upright posture, the present study aimed at replicating St-Amant et al.

The Fukuda Stepping Test Is Influenced by a Concurrent Cognitive Task and Step Height in Healthy Young Adults: A Descriptive Study.

The Fukuda stepping test assesses spatial orientation in people with vestibular disorders. To standardize the test, it is important to know which factors influence the outcome. This study investigated the impact of two factors, a concurrent cognitive task and step height, on the Fukuda stepping test in healthy individuals.

An fNIRS Investigation of Discrete and Continuous Cognitive Demands During Dual-Task Walking in Young Adults.

: Dual-task studies have demonstrated that walking is attention-demanding for younger adults. However, numerous studies have attributed this to task type rather than the amount of required to accomplish the task. This study examined four tasks: two discrete (i.

Effect of Dual Task on Step Variability during Stepping in Place without Vision.

Stepping in place without vision is a spatial orientation task that is associated with unperceived foot displacements. This study was aimed at determining whether foot displacement variability is modified by a concurrent cognitive task. Fourteen young adults stepped for 50 steps with their vision blocked and performed a continuous mental counting task.

Effect of Center of Mass Immobilization on Center of Pressure Displacement in Single and Dual-Task.

Recent research showed that artificially immobilizing the center of mass (COM) of participants in a standing position increased the center of pressure (COP) variability. This increase has been interpreted as an exploratory behavior. The objectives of this study are to investigate if this exploratory behavior is (1) reflected in other COP variables and (2) automatically controlled using a dual-task paradigm.

The effects of Kinesiology Tape on static postural control in individuals with functional ankle instability.

Objective: To investigate if applying Kinesiology Tape (KT) on the unstable ankle may improve static postural control in individuals with Functional ankle instability.

Design: A repeated measured study. Participants performed a series of static quiet bipedal and unipedal stances on a force platform.

Hemodynamic and behavioral changes in older adults during cognitively demanding dual tasks.

Introduction: Executive functions play a fundamental role in walking by integrating information from cognitive-motor pathways. Subtle changes in brain and behavior may help identify older adults who are more susceptible to executive function deficits with advancing age due to prefrontal cortex deterioration. This study aims to examine how older adults mitigate executive demands while walking during cognitively demanding tasks.

Unveilling the cerebral and sensory contributions to automatic postural control during dual-task standing.

Objectives: The postural control dual-task literature has demonstrated greater postural stability during dual-task in comparison to single task (i.e., standing balance alone through the examination of multiple kinetic and kinematic measures.

A functional near-infrared spectroscopy (fNIRS) examination of how self-initiated sequential movements become automatic.

The neural mechanisms underlying movement automaticity have been investigated using PET and fMRI and more recently functional near-infrared spectroscopy (fNIRS). As fNIRS is an emerging technique, the objective of the present study was to replicate the functional magnetic resonance imaging-related motor sequence findings as reported by Wu et al. (J Neurophysiol 91:1690-1698, https://doi.

Number of Trials Needed to Assess Postural Control of Young Adults in Single and Dual-Task.

Despite its popularity, there is a lack of standardization when assessing postural control. This study aimed to suggest how many trials should be used when assessing young adults' postural control with a specific single-task and dual-task quiet stance protocol. Two groups of 15 participants performed 20 trials of 60 s (feet together, eyes open) with or without a dual-task.

Automaticity of Postural Control while Dual-tasking Revealed in Young and Older Adults.

: Postural control improvements in external focus and cognitive task conditions are thought to occur because directing attention away from postural control allows greater automaticity. We aimed to support this theory by using three dynamic measures of postural control that may reveal changes in the structure or composition of sway: the discrete wavelet transform, sample entropy, and rambling trembling analyses.: We analyzed the center of pressure data from twenty-two healthy young adults (20.

The influence of carrying an anterior load on attention demand and obstacle clearance before, during, and after obstacle crossing.

Carrying an anterior load during obstacle negotiation increases attention demand, which may differ at various crossing stages. Less is known on the impact of lower visual field obstruction and the weight of the anterior load on obstacle negotiation and attention demand. The objectives of this study were to: (1) determine if carrying a weighted anterior load, lower visual field occlusion, or both, modify obstacle clearance and/or reaction time (RT); and (2) examine whether RT is modulated across obstacle crossing phases as measured by a probe RT protocol.

Absence of Ankle Stiffening While Standing in Focus and Cognitive Task Conditions in Older Adults.

Research suggests that an external focus or cognitive task may improve postural control. Removing attention from movement production may promote automaticity, or the tasks may promote ankle stiffening. To investigate these two theories, twenty older adults stood while performing baseline standing, internal focus, external focus, and two cognitive tasks.

Older and young adults adopt different postural strategies during quiet bipedal stance after ankle plantarflexor fatigue.

Background: The individual effects of fatigue and age on postural control have been extensively studied. However, there is a lack of knowledge about the combined effects of fatigue and age on postural control and posture.

Research Question: The purpose of this study was to investigate the influence of age and muscle fatigue on bipedal stance postural control and posture.

Effect of Bilateral and Unilateral Plantarflexor Muscle Fatigue on Blind Navigation Precision and Gait Parameters.

The objective was to evaluate the impact of bilateral and unilateral fatigue of the plantarflexor muscles on blind navigation. Thirty-eight young adults walked 8-m without vision before fatigue (pre-fatigue), then fatigued either one or both of their plantarflexor muscles by performing isometric contractions. After each fatigue, two blind navigation trials were performed (post-fatigue trials 1 and 2).

Reaction Time of Healthy Older Adults Is Reduced While Walking Fast.

Attentional requirements of walking at various speeds in older adults were examined. Twenty healthy older adults (69.9 ± 2.

Cognitive task modality influences postural control during quiet standing in healthy older adults.

Background: The interstimulus interval of a cognitive task was found to have a limited effect on postural control in young adults, while visual cognitive tasks were found to improve stability compared to auditory tasks. It is of interest to investigate whether postural control in healthy older adults is sensitive to these types of cognitive task manipulations.

Aims: The objectives of the present experiment were to evaluate the impact of interstimulus interval and modality of a continuous cognitive task on postural control in healthy older adults.

Improvements in Obstacle Clearance Parameters and Reaction Time Over a Series of Obstacles Revealed After Five Repeated Testing Sessions in Older Adults.

The purpose of this study was to investigate obstacle clearance and reaction time parameters when crossing a series of six obstacles in older adults. A second aim was to examine the repeated exposure of this testing protocol once per week for 5 weeks. In total, 10 older adults (five females; age: 67.

Balance and Mobility Training With or Without Simultaneous Cognitive Training Reduces Attention Demand But Does Not Improve Obstacle Clearance in Older Adults.

The purpose of this study was to determine whether balance and mobility training (BMT) or balance and mobility plus cognitive training (BMT + C) would improve obstacle clearance and reaction time (RT); whether further improvements would be exposed in the BMT + C group relative to the BMT group; and whether possible improvements would be sustained at the follow-up. Healthy older adults were allocated to the BMT (n = 15; age: 70.2 ± 3.

Effect of Transient Perturbations of Short-Term Memory on Target-Directed Blind Locomotion.

It is difficult to walk without vision to a nearby destination if there is a time delay between watching the destination and walking toward it. Indeed, path deviation occurred when delays were introduced before initiating straight ahead blindfolded walking (R. A.