Postural Control Performance Research Articles

Evaluating the Effects of Frequency of Subthalamic Nucleus Deep Brain Stimulation on Postural Control in Parkinson's Disease: A Case-Series Study.

Background/Objectives: Subthalamic nucleus deep brain stimulation (STN-DBS) is a standard treatment for motor complications in Parkinson's disease (PD). Its impact on axial symptoms is still not fully understood. This study aimed to quantitatively evaluate the effect of frequency changes within the therapeutic window on postural control performances of individuals with PD who underwent bilateral STN-DBS. Methods: Postural control was assessed using Computerized Dynamic Posturography with randomized DBS frequency parameters, low (60 Hz), high (130 Hz), and very high (180 Hz), across six sensory organization test (SOT) conditions. Results: Twenty PD participants with a mean age of 61.2 ± 10.1 years were included. There were no differences in equilibrium scores of SOT conditions between 60, 130, and 180 Hz frequencies (p > 0.05), except the SOT6 score (p = 0.003), where 60 Hz showed better equilibrium performance in SOT6, indicating an advantage in postural control when visual cues are disturbed. Discussion: Low-frequency settings (60 Hz) in STN-DBS may benefit those who rely heavily on visual cues while ineffectively using somatosensory and vestibular inputs. Conclusions: A tailored approach to the DBS frequency setting could optimize postural stability and reduce fall risk in these patients. Future research is needed to explore these mechanisms to enhance therapeutic strategies.

Assessing acute effects of two motor-cognitive training modalities on cognitive functions, postural control, and gait stability in older adults: a randomized crossover study.

The process of aging often accompanies a decline in cognitive function, postural control, and gait stability, consequently increasing the susceptibility to falls among older individuals. In response to these challenges, motor-cognitive training has emerged as a potential intervention to mitigate age-related declines. This study aims to assess the acute effects of two distinct motor-cognitive training modalities, treadmill dual-task training (TMDT) and interactive motor-cognitive training (IMCT), on cognitive function, postural control, walking ability, and dual-task performance in the elderly population. In this randomized crossover study, 35 healthy elderly individuals (aged 60-75) participated in three acute training sessions involving TMDT, IMCT, and a control reading condition. Assessments of executive function, postural control, gait performance, and cognitive accuracy were conducted both before and after each session. Both TMDT and IMCT improved executive functions. Notably, IMCT resulted in a significant enhancement in correct response rates and a reduction in reaction times in the Stroop task (p < 0.05) compared to TMDT and the control condition. IMCT also led to an increase in dual-task gait speed (p < 0.001) and showed a trend towards improved cognitive accuracy (p = 0.07). Conversely, TMDT increased postural sway with eyes open (p = 0.013), indicating a potential detriment to postural control. The findings suggest that IMCT holds greater immediate efficacy in enhancing cognitive function and gait stability among older adults compared to TMDT, with a lesser adverse impact on postural control. This underscores the potential of IMCT as a preferred approach for mitigating fall risk and enhancing both cognitive and physical functions in the elderly population.

The Effect of Different Sensory Perturbations on Postural Control and Fall Risk in Benign Paroxysmal Positional Vertigo Patients.

Benign paroxysmal positional vertigo (BPPV) patients may experience balance problems in various environmental conditions other than positional dizziness. Therefore, there is a need to investigate the postural control abilities and the ability to use sensory inputs in BPPV patients in different conditions. The aim of this study was to examine the postural control performance of middle-aged adult BPPV patients in easy and difficult balance tasks, the effect of vestibular stimulation on the maintenance of balance, and the risk of falling, by posturographic evaluation in various conditions. A total of 26 patients diagnosed with posterior canal BPPV and 26 controls were included in the study. Sensory Organization Test (SOT), Vestibular Stimulation Test (VST), and fall risk assessment (FRA) were applied to the participants, respectively. Significant difference was observed in SOT medio-lateral (ML) plane in Conditions 2 and 5 (p < .05). A significant difference was observed in the vestibular score in the SOT ML plane. No significant difference was observed in VST test scores (p > .05). In the FRA test, a significant difference was observed in the energy and gain parameters in the anterio-posterior plane (p < .05). The current study examined postural control abilities of patients with BPPV in extensive external conditions and in both planes, using various sensory perturbations and stimulation. It was thought that while BPPV patients were in the active phase of the disease, their postural control skills in the ML plane decreased and they might be at risk of falling.

The effects of six weeks of combined balance and plyometric training on postural control performance in elite badminton players: A pilot randomized, controlled study

Background/ObjectivesThe athletic performance in badminton players largely depends on the capability of dynamic postural control to quickly restore balance when performing high-paced movements (e.g., frequent single-leg jumps). Our aim was to examine the effects of a novel intervention that combines balance training on an unstable surface and plyometric training on the performance of restoring balance after jumping, as well as related postural control in elite badminton players. MethodsSixteen elite male badminton players were randomly allocated to either a combined balance and plyometric training group (CT, n = 8) or a plyometric training group (PT, n = 8). The CT group participated in a six-week training program, which included three training sessions per week. Each session comprised 40 min of plyometric exercises and 20 min of balance training. The PT group underwent plyometric training using the identical protocol as that of the CT group. All participants underwent identical technical training in badminton throughout the duration of the study. At baseline and immediately after the intervention, participants completed a single-leg jumping test. The capacity to restore balance was evaluated using the time to stabilization (TTS) after landing; and the related center of pressure (COP) fluctuations were also recorded. The effect of intervention was examined by two-way repeated-measures of ANOVA. ResultsThe primary two-way repeated-measures ANOVA models showed no significant interactions between group and time on either the time to stability in the dominant leg (D-TTS) or the time to stability in the non-dominant leg (N-TTS) (p > 0.70). Significant main effects of time, group, and their interactions on dominant legs of the anterior-posterior displacement difference (D-COPAP) (time: p = 0.001; group: p = 0.001; interaction: p = 0.014), non-dominant legs of the anterior-posterior displacement difference (N-COPAP) (time: p < 0.001; group: p = 0.003; interaction: p = 0.021) and non-dominant legs of the medial-lateral displacement difference (N-COPML) (time: p < 0.001; group: p < 0.001; interaction: p = 0.026), that is, compared to baseline of both groups and post PT, the COP metrics were significantly reduced after CT. Secondarily, within the CT and PT group, after the intervention, the N-TTS (CT: p = 0.001, post: 0.58 ± 0.87; PT: p = 0.03, post: 0.71 ± 0.11) was significantly decreased compared to baseline (CT pre: 0.76 ± 0.16; PT pre: 0.88 ± 0.13). ConclusionThis pilot study demonstrated that, compared to PT-only, the 6-week CT which combines balance training induced comparable improvements in the capacity to restoring balance after landing from a single-leg jump, and significantly improved the postural control performance as measured by COP metrics.

Neural Mechanisms Associated With Postural Control in Collegiate Soccer and Non-Soccer Athletes.

Sport-specific training may improve postural control, while repetitive head acceleration events (RHAEs) may compromise it. Understanding the neural mechanisms underlying postural control may contextualize changes due to training and RHAE. The goal of this study was to determine whether postural sway during the Balance Error Scoring System (BESS) is related to white matter organization (WMO) in collegiate athletes. Collegiate soccer ( N =33) and non-soccer athletes ( N =44) completed BESS and diffusion tensor imaging. Postural sway during each BESS stance, fractional anisotropy (FA), and mean diffusivity (MD) were extracted for each participant. Partial least squares analyses determined group differences in postural sway and WMO and the relationship between postural sway and WMO in soccer and non-soccer athletes separately. Soccer athletes displayed better performance during BESS 6, with lower FA and higher MD in the medial lemniscus (ML) and inferior cerebellar peduncle (ICP), compared to non-soccer athletes. In soccer athletes, lower sway during BESS 2, 5, and 6 was associated with higher FA and lower MD in the corticospinal tract, ML, and ICP. In non-soccer athletes, lower sway during BESS 2 and 4 was associated with higher FA and lower MD in the ML and ICP. BESS 1 was associated with higher FA, and BESS 3 was associated with lower MD in the same tracts in non-soccer athletes. Soccer and non-soccer athletes showed unique relationships between sway and WMO, suggesting that sport-specific exposures are partly responsible for changes in neurological structure and accompanying postural control performance and should be considered when evaluating postural control after injury.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content, available at: http://links.lww.com/JNPT/A472 ).

Dominance of attentional focus: a comparative study on its impact on standing postural control in healthy younger and older adults.

Attentional focus is a phenomenon in which shifting the focus of attention alters performance of standing postural control. It can be categorized as internal focus (IF), which directs attention to the body parts, or external focus (EF), which directs attention to the external environment. Although attentional focus that improves standing postural control in younger people exhibits individual dominance, the dominance of attentional focus in standing postural control in older adults remains ambiguous. Therefore, this study aimed to compare the dominance of attentional focus in standing postural control between healthy younger and older adults, a crucial step for understanding the aging process. The participants performed a standing postural control task under the IF and EF conditions. Based on the condition during which they exhibited superior performance, the participants were divided into two groups: IF-dominant and EF-dominant. The standing postural control performance in each group under the IF and EF conditions was subsequently compared. The results showed that the participants, encompassing both younger and older adults, were divided into the IF-dominant and EF-dominant groups, confirming the dominance of attentional focus. The performance under the EF condition in older adults was also influenced by the dominance of attentional focus. These results highlight the potential importance of intervention methods based on the dominance of attentional focus, providing valuable insights into future research and clinical practice.

Postural control performance of active and inactive older adults during manipulation of sensory information tests: a cross-sectional study

Postural control performance of active and inactive older adults during manipulation of sensory information tests: a cross-sectional study

Impact of foot sole insensitivity and reduced nerve conduction velocity on postural control and functional gait

Peripheral neuropathy is characterized by decreased foot sole sensitivity and slowed nerve conduction velocity, leading to impaired postural control and functional gait performance. This study assessed the differential effects of reduced foot sole sensitivity and slowed nerve conduction velocity on postural control and functional gait. Thirty-five participants were evaluated for two main clinical symptoms: the H-index and foot sole sensitivity. Two times the square of the height (H) of the individual divided by the latency (T) between the onsets of the M- and H-waves of the H-reflex were used to calculate the H-index (2 &amp;times; [H/T]2). Foot sole sensitivity was evaluated using a monofilament on five sites at the bottom of the foot. Participants were categorized into three symptomological groups: (i) less affected (LA), (ii) moderately affected (MA), and (iii) severely affected (SA), based on their H-index ranges of 78.0 &amp;ndash; 109.4, 42.8 &amp;ndash; 76.6, and 45.6 &amp;ndash; 75.5 cm2/ms2, respectively, and foot sole sensitivity score ranges of 6 &amp;ndash; 10, 6 &amp;ndash; 10, and 0 &amp;ndash; 5, respectively. Outcome variables included center of pressure (COP) standard deviation in the anteroposterior direction and COP average velocity (Vavg) during 30 s of eyes-open quiet standing, as well as 6-min walk distance (6MWD) and timed-up-and-go duration (TUG). Multivariate analysis revealed significant group differences (P &lt; 0.05), with post hoc analysis showing significant differences between LA and SA in Vavg (F4,30 = 3.752; P = 0.014). Discriminant analysis revealed Vavg as the primary determinant, while 6MWD and TUG were secondary determinants of group separation. Notably, enhanced functional gait was associated solely with sensitive foot soles and heightened nerve conduction velocity within the LA group, not in the MA or SA groups. Disease severity mediated the specific effects on postural control and functional gait, underscoring the importance of tailoring rehabilitation protocols to address individual symptoms.

Postural control and cognitive flexibility in skilled athletes: Insights from dual-task performance and event-related potentials

Athletes of skill-oriented sports (hereinafter referred to as “skilled athletes”), such as gymnasts and rhythmic gymnasts, have demonstrated better postural control than nonathletes. However, previous studies have mainly focused on single postural tasks and have not considered how skilled athletes use and allocate attentional resources during postural control. This research used the event-related potential (ERP) to explore the postural control performance of skilled athletes under cognitive processes and their utilization and allocation of attentional resources. A dual-task paradigm was used to simulate the actual situation in sports. 26 skilled athletes and 26 nonathletes were required to perform postural control and task-switching simultaneously. The results showed that skilled athletes demonstrated more postural control stability and a higher accuracy of task-switching than nonathletes in all dual tasks. Compared with nonathletes, they showed a stable enhanced N1 (electrodes: Oz, O1, and O2) amplitude during three postures. Moreover, larger N2 component on Fz, FCz, and Cz and theta band power was found in the frontal cortex (on Fz, FCz) of skilled athletes under feet together and single leg standing posture. The study illustrated that skilled athletes show greater frontal activation during dual tasks, which allows for more rational and flexible brain attentional resource input and allocation in cognitive processes, this may be due to long-term professional training, which enables them to have a higher level of automation of postural control and cognitive flexibility. This study’s results offer valuable insights into the interplay between postural control and multitasking in skilled athletes, and its outcomes carry significant implications for the training and assessment of athletes across various sports.

Ground reaction forces better than center of pressure differentiate postural control between young female volleyball players and untrained peers

A comprehensive explanation of the relationship between postural control and athletic performance requires compare body balance in athletes with their never training counterparts. To fill this gap in relation to volleyball, the aim of this study was to compare the balance of intermediate adolescent female players (VOL, n = 61) with inactive peers (CON, n = 57). The participants were investigated in normal quiet stance during 20 s trials on a Kistler force plate. The traditional spatial (amplitude and mean speed) and temporal (frequency and entropy) indices were computed for ground reaction forces (GRF) and center-of-pressure (COP) time-series. The spatial parameters of the both time-series did not discriminate the two groups. However, the temporal GRF parameters revealed much lower values in VOL than in CON (p < .0001). This leads to three important conclusions regarding posturography applications. First, GRF and COP provide different information regarding postural control. Second, measures based on GRF are more sensitive to changes in balance related to volleyball training and perhaps to similar training and sports activity regimens. And third, the indicators calculated based on these two time series can complement each other and thus enrich the insight into the relationship between balance and sports performance level.

Effects of a Passive Back-Support Exosuit on Postural Control and Cognitive Performance During a Fatigue-Inducing Posture Maintenance Task.

To evaluate the effectiveness of passive back-support exosuit on postural control and cognitive performance during a fatigue-inducing posture maintenance task. Wearable support systems (exoskeletons/exosuits) reduce physical demands but may also influence postural control and cognitive performance by reducing muscular fatigue. Eighteen participants visited on two different days to test an exosuit system and performed dual-task cognitive assessments based on human information processing (information acquisition, information integration, and action implementation) while maintaining a 35° trunk flexion posture for 16minutes. Center-of-pressure (CoP), cognitive performance, and perceived workload were recorded, while erector spinae muscle activity was captured to quantify muscle fatigue. The exosuit was effective in reducing erector spinae muscle fatigue during the static posture maintenance task (61% less in Δmedian frequency: -9.5Hz (EXO-Off) versus -3.7Hz (EXO-On)). The fatigue-inducing task increased CoP velocity as a function of time (29% greater: 9.3mm/sec (pre) versus 12.0mm/sec (post)), and exosuit use decreased CoP velocity (23% less: 12.1mm/sec (EXO-Off) versus 9.4mm/sec (EXO-On)). The exosuit was also effective at mitigating cognitive degradation, as evidenced by a higher hit-to-signal ratio (8% greater: 81.3 (EXO-Off) versus 87.9 (EXO-On)) in the information integration task and reducing perceived workload in all stages of human information processing. Exosuit provided benefits of postural control and information integration processing during a 16-min static posture maintenance task. Torso exoskeletons/suits can have positive implications for occupations with concurrent physical and cognitive demands.

Comparison Between Effects of Galvanic and Vibration-Based Vestibular Stimulation on Postural Control and Gait Performance in Healthy Participants: A Systematic Review of Cross-Sectional Studies.

Electricity and vibration were two commonly used physical agents to provide vestibular stimulation in previous studies. This study aimed to systematically review the effects of galvanic (GVS) and vibration-based vestibular stimulation (VVS) on gait performance and postural control in healthy participants. Five bioscience and engineering databases, including MEDLINE via PubMed, CINAHL via EBSCO, Cochrane Library, Scopus, and Embase, were searched until March 19th, 2023. Studies published between 2000 and 2023 in English involving GVS and VVS related to gait performance and postural control were included. The procedure was followed via the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. The methodological quality of included studies was assessed using the NIH study quality assessment tool for observational cohort and cross-sectional studies. A total of 55 cross-sectional studies met the inclusion criteria and were included in this study. Five studies were good-quality while 49 were moderate-quality and 1 was poor-quality. There were 50 included studies involving GVS and 5 included studies involving VVS. GVS and VVS utilized different physical agents to provide vestibular stimulation and demonstrated similar effects on vestibular perception. Supra-threshold GVS and VVS produced vestibular perturbation that impaired gait performance and postural control, while sub-threshold GVS and VVS induced stochastic resonance phenomenon that led to an improvement. Bilateral vestibular stimulation demonstrated a greater effect on gait and posture than unilateral vestibular stimulation. Compared to GVS, VVS had the characteristics of better tolerance and fewer side effects, which may substitute GVS to provide more acceptable vestibular stimulation.

Kinematic characteristics of gait with different myopia: a cross-sectional study.

Myopia, a condition affecting approximately one-quarter of the world' s population, has been projected to double in prevalence by the year 2050. It can have an impact on postural control during walking and can increase the risk of falls and injuries. (1) To examine the abnormal performance of postural control during walking in male college students who used convex lenses for myopia intervention from a kinematic perspective; (2) to establish theoretical foundation for preventing falls and injuries in the myopic population. A total of 22 male college students participated in this study. The center of gravity (COG), the percentage of gait cycle (PGC) and the joint angle(JT) were collected as indications of postural control during walking. A quantitative analysis was conducted using a One-Way Repeated Measures ANOVA to examine the variations among the three groups. During myopic interventions, (1) the range of vertical COG changes is significant to be greater compared with normal vision (P < 0.05). (2) there was an significant increase in the PGC in single-legged support, accompanied by a decrease in the PGC in double-legged support, compared with normal vision (P < 0.05). (3) The myopic intervention leads to increased variability in JT of the hip and the knee during the single-leg support and swing, as compared to individuals with normal vision (P < 0.05). Severe myopic interventions result in more changes in JT of ankle. Myopia has been found to have a negative impact on postural control during walking, leading to changes in balance, increased instability, and an elevated risk of injury.

Postural control in emotional states: An effect of biofeedback

BackgroundEmotional states in the short term and affective impairments, such as anxiety and depression in the long run, can have a significant impact on postural control. Individuals with these conditions often struggle with maintaining balance during emotionally charged situations, which can increase their risk of falls and injuries. Biofeedback has been proposed as a potential intervention to improve postural control during emotional induction. Research questionHow do emotional stimuli affect postural control performance in the presence of real-time postural feedback? MethodsForty-two participants took part in the study. The visual stimuli used in the experiment to induce emotions of various valence in the subjects were video clips, containing a series of pictures (24 positive, 24 neutral and 24 negative pictures). During the experiment, participants were required to maintain balance standing on a force platform while watching the videos on a computer screen. For each subject, three sessions of 480 s were generated, each of which included two conditions: with and without biofeedback (a target on the screen indicating the subject’s position relative to the center of pressure (CoP). ResultsThe No Feedback condition provoked a higher medial-lateral and anterior-posterior sway, but lower velocity of CoP than the Feedback condition. We did not find any effect of the valence of emotional videos on indicators of postural control in No Feedback condition. However, both negative and positive videos provoked a lower velocity of CoP in comparison to neutral videos in the Feedback condition. SignificanceChanges observed in postural control during the Feedback condition in the presence of emotional stimuli (both negative and positive) could be explained by the shift in attention from the task of maintaining posture to the emotional videos. The results of this study have important implications for clinicians involved in postural training and rehabilitation.

Vestibular function and balance performance in children with sensorineural hearing loss

Objective Balance difficulties are common in children with sensorineural hearing loss (SNHL). For some of these children, concomitant vestibular deficits may impact postural control. This study aimed to explore vestibular function, functional balance and postural control, and the relationship between these measures in children with SNHL. Design Cross-sectional study quantifying peripheral vestibular function (vestibular evoked myogenic potentials [VEMP], video head impulse test), functional balance (Bruininks–Oseretsky Test of Motor Proficiency [BOT]) and postural control (static posturography with modified sensory inputs). The relationship between the degree of vestibular impairment, functional balance and postural control was explored. Study sample Eleven with SNHL, and 11 with normal sound detection (NSD) between 5 and 12 years of age. Results Children with SNHL had varying degrees of vestibular dysfunction and differences in overall balance performance. Across all children, greater degrees of vestibular impairment were associated with significantly poorer functional balance and postural control performance for complex standing conditions (BOT percentile rank p = 0.001; compliant surface eyes open [EO]: p = 0.027; compliant surface eyes closed: p = 0.048). Conclusions Vestibular dysfunction in children with SNHL was variable. Vestibular impairment predicted poorer functional balance performance and postural control abilities, including differences in postural sway patterns.

Fronto-parietal theta high-definition transcranial alternating current stimulation may modulate working memory under postural control conditions in young healthy adults.

This study aimed to investigate the immediate effects of fronto-parietal θ HD-tACS on a dual task of working memory-postural control. In this within-subject cross-over pilot study, we assessed the effects of 20 min of 6 Hz-tACS targeting both the left dorsolateral prefrontal cortex (lDLPFC) and posterior parietal cortex (PPC) in 20 healthy adults (age: 21.6 ± 1.3 years). During each session, single- and dual-task behavioral tests (working memory single-task, static tandem standing, and a dual-task of working memory-postural control) and closed-eye resting-state EEG were assessed before and immediately after stimulation. Within the tACS group, we found a 5.3% significant decrease in working memory response time under the dual-task following tACS (t = -3.157, p = 0.005, Cohen's d = 0.742); phase synchronization analysis revealed a significant increase in the phase locking value (PLV) of θ band between F3 and P3 after tACS (p = 0.010, Cohen's d = 0.637). Correlation analyses revealed a significant correlation between increased rs-EEG θ power in the F3 and P3 channels and faster reaction time (r = -0.515, p = 0.02; r = -0.483, p = 0.031, respectively) in the dual-task working memory task after tACS. However, no differences were observed on either upright postural control performance or rs-EEG results (p-values <0.05). Fronto-parietal θ HD-tACS has the potential of being a neuromodulatory tool for improving working memory performance in dual-task situations, but its effect on the modulation of concurrently performed postural control tasks requires further investigation.

Analysis of Postural Control in Patients Diagnosed with Unilateral Knee Osteoarthrosis and Its Relationship with the Risk of Falls.

Knee osteoarthrosis, whether subtle or marked, appears to alter the stability and performance of the knee joint in activities of daily living that prevent the maintenance of bipedal posture. However, there is still a gap in the literature as to how knee osteoarthritis can affect static balance. To analyze the performance of postural control in elderly diagnosed with unilateral knee osteoarthrosis. 40 elderly people of both sexes participated in this study, divided into two groups containing 20 elderly each. Group 1 (G1) consists of elderly patients who have received a diagnosis of unilateral knee osteoarthritis. Despite undergoing conservative treatment, their condition has shown insufficient improvement, leading to a clinical recommendation for total knee arthroplasty (TKA). The G2 group was made up of 20 elderly with an average age of 71.09 years, considered active, who do not have a diagnosis of osteoarthritis in the knee joint and practice physical activity. With the aid of a Baroscan pressure platform, the center of pressure (COP) displacement in the anteroposterior (COPAP) direction and mediolateral direction (COPML) and the area of center of pressure displacement were evaluated during bipedal postural control with eyes open and eyes closed. During postural control with eyes open and eyes closed, the G1 group showed greater displacement of the COP in the anteroposterior direction-COPAP (p = 0.007)-and mediolateral direction-COPML (p = 0.033)-when compared to the G2 group. As for the area of displacement of the COP, group G1 presented a larger area of displacement (p = 0.002) than group G2 during bipedal postural control with open eyes. For the condition with eyes closed, both groups showed similar behaviors, which resulted in no present statistically significant differences. The results suggest that unilateral knee osteoarthritis influences bipedal postural control and activities of daily living that require this static balance, since information from the somatosensory system is reduced, resulting in stability of tasks that require body control and promoting the risk of falls. From a clinical perspective, the results suggest that the assessment of bipedal postural control can assist orthopedic physicians in assessing joint stability in patients with unilateral knee osteoarthrosis.

The effect of warm-up on postural sway in the dominant and non-dominant leg

Although the chronic effects of a long-term warm-up program have been widely studied, to our knowledge, the number of studies examining the acute effects of a single warm-up session on inter-limb balance asymmetries in symmetrical sports such as cycling is limited. The aim of this study was to examine the effect of warm-up on postural sway in the dominant and non-dominant leg in male bicycle athletes. Sixteen healthy young male volunteers who engage in cycling sports participated in the study. The participants' age was determined as 15.50±1.15 years, body weight as 56.06±7.79 kg, height as 169.87±4.98 cm, and sports experience as 4.31±1.25 years. The postural control performance on the dominant and non-dominant leg of the athletes was evaluated on Biodex Balance System balance device platform for 20 seconds before and after a 10-minute warm-up exercise performed at a constant pedaling frequency of 80 RPM on a bicycle ergometer. In the comparison of the pre-test to post-test dominant leg Overall Sway Index (t=3.456; p=0.004), Anterior-Posterior (Z=-3.160; p=0.002) and Medial-Lateral (Z=-2.428; p=0.015) postural control scores of the participants, a significant decrease was found in the post-test. It was determined that warm-up exercise can only improve acute postural control in the dominant leg. The effects of the study can be extended to different sports branches with symmetrical features in order to obtain comparable results.

Counseling Patients with Chronic Obstructive Pulmonary Disease Traveling to High Altitude.

Bloch, Konrad E., Talant M. Sooronbaev, Silvia Ulrich, Mona Lichtblau, and Michael Furian. Clinician's corner: counseling patients with chronic obstructive pulmonary disease traveling to high altitude. High Alt Med Biol. 24:158-166, 2023.-Mountain travel is increasingly popular also among patients with chronic obstructive pulmonary disease (COPD), a highly prevalent condition often associated with cardiovascular and systemic manifestations. Recent studies have shown that nonhypercapnic and only mildly hypoxemic lowlanders with moderate to severe airflow obstruction owing to COPD experience dyspnea, exercise limitation, and sleep disturbances when traveling up to 3,100 m. Altitude-related adverse health effects (ARAHE) in patients with COPD include severe hypoxemia, which may be asymptomatic but expose patients to the risk of excessive systemic and pulmonary hypertension, cardiac arrhythmia, and even myocardial or cerebral ischemia. In addition, hypobaric hypoxia may impair postural control, psycho-motor, and cognitive performance in patients with COPD during altitude sojourns. Randomized, placebo-controlled trials have shown that preventive treatment with oxygen at night or with acetazolamide reduces the risk of ARAHE in patients with COPD while preventive dexamethasone treatment improves oxygenation and altitude-induced excessive sleep apnea, and lowers systemic and pulmonary artery pressure. This clinical review provides suggestions for pretravel assessment and preparations and measures during travel that may reduce the risk of ARAHE and contribute to pleasant mountain journeys of patients with COPD.

Effect of dual-task interaction combining postural and visual perturbations on cortical activity and postural control ability

Previous studies have suggested cortical involvement in postural control in humans by measuring cortical activities and conducting dual-task paradigms. In dual-task paradigms, task performance deteriorates and can be facilitated in specific dual-task settings. Theoretical frameworks explaining these dual-task interactions have been proposed and debated for decades. Therefore, we investigated postural control performance under different visual conditions using a virtual reality system, simultaneously measuring cortical activities with a functional near-infrared spectroscopy system. Twenty-four healthy participants were included in this study. Postural stability and cortical activities after perturbations were measured under several conditions consisting of postural and visual perturbations. The results showed that concurrent visual and postural perturbations could facilitate cortical activities in the supplementary motor area and superior parietal lobe. Additionally, visual distractors deteriorated postural control ability and cortical activation of the supplementary motor area. These findings supported the theoretical framework of the “Cross talk model”, in which concurrent tasks using similar neural domains can facilitate these task performances. Furthermore, it indicated that the cortical resource capacity and domains activated for information processing should be considered in experiments involving dual-task paradigms and training.