Region-specific Effects of Transcranial Direct Current Stimulation Over Posterior Parietal Cortex and Cerebellum on Standing Postural Displacement After Prism Adaptation.

Prism adaptation (PA) induces the after-effects of adapted tasks and transfers after-effects of non-adapted tasks, in which PA with pointing movements transfers to postural displacement during eyes-closed standing. However, the neural mechanisms underlying the transfer of PA after-effects on standing postural displacement remain unclear. The present study investigated the region-specific effects of transcranial direct current stimulation (tDCS) over the posterior parietal cortex (PPC) and cerebellum during prism exposure (PE) on standing postural displacement in healthy adults.

Influence of postural control difficulty on changes in spatial orienting of attention after leftward prism adaptation.

Prism adaptation (PA) affects visuospatial attention such as spatial orienting in both the right and left hemifields; however, the systematic after-effects of PA on visuospatial attention remain unclear. Visuospatial attention can be affected by non-spatial attentional factors, and postural control difficulty, which delays the reaction time (RT) to external stimulation, may be one such factor. Therefore, we aimed to investigate the influence of postural control difficulty on changes in spatial orienting of attention after leftward PA.

Prism adaptation during balance standing enhances the transfer after-effect on standing postural displacement.

Prism adaptation (PA) is a sensorimotor adaptation paradigm that induces after-effects of adapted tasks and transfer after-effects of non-adapted tasks. Previous studies showed inconsistent results of transfer after-effects of adaptation to a leftward prismatic shift on the center-of-pressure (COP) displacement during eyes-closed standing. Challenging balance during PA increases the generalization of the internal model to untrained movements, resulting in increased transfer after-effects.

Influences of different cognitive loads on central common neural drives to the ankle muscles during dual-task walking.

While dual-task walking with additional cognitive tasks may decrease walking performance, many studies have also shown increases in walking performance during dual tasks, especially as cognitive load increases. However, the neural mechanisms that cause changes in postural control during dual tasks according to the difference in cognitive load remain unclear. Therefore, this study aimed to investigate the influence of different cognitive loads on the neural control of muscle activity during dual-task walking using intra- and intermuscular coherence analyses.

Rhythmic auditory stimulation during gait adaptation enhances learning aftereffects and savings by reducing common neural drives to lower limb muscles.

Rhythmic auditory stimulation (RAS) improves gait symmetry in neurological patients with asymmetric gait patterns. However, whether RAS can accelerate gait adaptation remains unclear. This study aimed to investigate whether RAS during gait adaptation can enhance learning aftereffects and savings of gait symmetries.

Different modulation of oscillatory common neural drives to ankle muscles during abrupt and gradual gait adaptations.

Different neural contributions to motor learning might be involved when different error sizes of perturbation are introduced. Although the corticospinal drive contributes to abrupt gait adaptation processes, no studies have investigated whether cortical involvement during gait differs between perturbations applied abruptly and gradually. This study aimed to investigate the differences in oscillatory common neural drives to ankle muscles during gait between abrupt and gradual adaptations, using coherence analyses of paired surface electromyographic (EMG) recordings.

Immediate effects of stance and swing phase training on gait in patients with stroke.

To compare the effects of gait trainings targeting the stance (stance training) and the swing phases (swing training) among the subjects with stroke, and quantify the characteristics in the subjects who benefitted from either the stance training or the swing training. Sixteen subjects with stroke performed the stance training, which focused on the center of pressure to move from the heel to the forefoot, and the swing training, which focused on the improvement of hip flexion in the swing phase. To investigate the immediate effects of the stance training and the swing training, the instrumented gait analysis was performed before and after training.

Gait-combined transcranial alternating current stimulation modulates cortical control of muscle activities during gait.

Non-invasive brain stimulation has been of interest as a therapeutic tool to modulate cortical excitability. However, there is little evidence that oscillatory brain stimulation can modulate the cortical control of muscle activities during gait, which can be assessed using coherence analysis of paired surface electromyographic (EMG) recordings. This study aimed to investigate the effects of gait-combined transcranial alternating current stimulation (tACS) at the gait cycle frequency on the cortical control of muscle activities during gait using EMG-EMG coherence analysis.

Gait kinematics and physical function that most affect intralimb coordination in patients with stroke.

Background: Disturbed lower limb coordination is thought to limit gait ability in patients with stroke. However, the relationship of lower limb coordination with gait kinematics and physical function has not yet been clarified.

Objective: The purpose of the study was to clarify the gait kinematic and physical function variables that most affect intralimb coordination by using the continuous relative phase (CRP) between the thigh and shank.

Gait-synchronized oscillatory brain stimulation modulates common neural drives to ankle muscles in patients after stroke: A pilot study.

The present study aimed to investigate the long-term effects of gait intervention with transcranial alternating current stimulation (tACS) synchronized with gait cycle frequency on the cortical control of muscle activity during gait, using coherence analyses, in patients after stroke. Eight chronic post-stroke patients participated in a single-blinded crossover study, and 7 patients completed the long-term intervention. Each patient received tACS over the primary motor cortex foot area on the affected side, which was synchronized with individual gait cycle frequency, and sham stimulation during treadmill gait in a random order.

Gait-Synchronized Rhythmic Brain Stimulation Improves Poststroke Gait Disturbance: A Pilot Study.

Background and Purpose- Gait disturbance is one of serious impairments lowering activity of daily life in poststroke patients. The patients often show reduced hip and knee joint flexion and ankle dorsiflexion of the lower limbs during the swing phase of gait, which is partly controlled by the primary motor cortex (M1). In the present study, we investigated whether gait-synchronized rhythmic brain stimulation targeting swing phase-related M1 activity can improve gait function in poststroke patients.

Number of Synergies Is Dependent on Spasticity and Gait Kinetics in Children With Cerebral Palsy.

Purpose: Children with cerebral palsy have motor dysfunctions, which are mainly associated with the loss of motor coordination. For the assessment of motor coordination, muscle synergies calculated by nonnegative matrix factorization have been investigated. However, the characteristics of muscle synergies in children with cerebral palsy are not understood.

Ankle muscle coactivation and its relationship with ankle joint kinematics and kinetics during gait in hemiplegic patients after stroke.

Introduction: Increased ankle muscle coactivation during gait is a compensation strategy for enhancing postural stability in patients after stroke. However, no previous studies have demonstrated that increased ankle muscle coactivation influenced ankle joint movements during gait in patients after stroke.

Purpose: To investigate the relationship between ankle muscle coactivation and ankle joint movements in hemiplegic patients after stroke.

Clinical factors associated with ankle muscle coactivation during gait in adults after stroke.

Background: Increased ankle muscle coactivation during gait represents an adaptation strategy to compensate for postural instability in adults after stroke. Although increased ankle muscle coactivation is correlated with gait disorders in adults after stroke, it remains unclear which physical impairments are the most predictive clinical factors explaining ankle muscle coactivation during gait.

Objective: To investigate these physical impairments in adults after stroke using stepwise multiple regression analyses.

Ankle muscle coactivation during gait is decreased immediately after anterior weight shift practice in adults after stroke.

Increased ankle muscle coactivation during gait has frequently been observed as an adaptation strategy to compensate for postural instability in adults after stroke. However, it remains unclear whether the muscle coactivation pattern increases or decreases after balance training. The aim of this study was to investigate the immediate effects of balance practice on ankle muscle coactivation during gait in adults after stroke.

Descending neural drives to ankle muscles during gait and their relationships with clinical functions in patients after stroke.

Objective: The objective of this study was to investigate the descending neural drive to ankle muscles during gait in stroke patients using a coherence analysis of surface electromyographic (EMG) recordings and the relationships of the drive with clinical functions.

Methods: EMG recordings of the paired tibialis anterior (TA), medial and lateral gastrocnemius (MG and LG), and TA-LG muscles were used to calculate intramuscular, synergistic, and agonist-antagonist muscle coherence, respectively, in 11 stroke patients and 9 healthy controls. Paretic motor function, sensory function, spasticity, ankle muscle strength, and gait performance were evaluated.

Reduction in energy expenditure during walking using an automated stride assistance device in healthy young adults.

Objective: To investigate the effects of an automated stride assistance device that assists hip joint flexion and extension movement in energy expenditure during walking in healthy young adults using an expired gas method.

Design: Prospective, single-group design to compare the differences of energy expenditure between 2 assistive conditions.

Setting: Laboratory.