<jats:p><jats:italic><jats:bold>Purpose</jats:bold>:</jats:italic> The aim of this study was to examine whether cortical activity changes during exercise with increasing cognitive demands in preadolescent children. <jats:italic><jats:bold>Method</jats:bold>:</jats:italic> Twenty healthy children (8.75 [0.91] y) performed one movement game, which was conducted with lower and higher cognitive demands. During a baseline measurement and both exercise conditions, cortical activity was recorded using a 64-channel electroencephalographic system, and heart rate was assessed. Ratings of perceived excertion and perceived cognitive engagement were examined after each condition. To analyze power spectral density in the theta, alpha-1, and alpha-2 frequency bands, an adaptive mixture independent component analysis was used to determine the spatiotemporal sources of cortical activity, and brain components were clustered to identify spatial clusters. <jats:italic><jats:bold>Results</jats:bold>:</jats:italic> One-way repeated-measures analyses of variance revealed significant main effects for condition on theta in the prefrontal cluster, on alpha-1 in the prefrontal, central, bilateral motor, bilateral parieto-occipital, and occipital clusters, and on alpha-2 in the left motor, central, and left parieto-occipital clusters. Compared with the lower cognitive demand exercise, cortical activity was significantly higher in theta power in the prefrontal cluster and in alpha-1 power in the occipital cluster during the higher cognitive demand exercise. <jats:italic><jats:bold>Conclusion</jats:bold>:</jats:italic> The present study shows that exercise complexity seems to influence cortical processing as it increased with increasing cognitive demands.</jats:p>

<jats:sec><jats:title>Introduction</jats:title><jats:p>Exergames are increasingly used in rehabilitation settings for older adults to train physical and cognitive abilities. To meet the potential that exergames hold, they need to be adapted to the individual abilities of the player and their training objectives. Therefore, it is important to know whether and how game characteristics affect their playing. The aim of this study is to investigate the effect of two different kinds of exergame (step game and balance game) played at two difficulty levels on brain activity and physical activity.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Twenty-eight older independently living adults played two different exergames at two difficulty levels each. In addition, the same movements as during gaming (leaning sideways with feet in place and stepping sideways) were performed as reference movements. Brain activity was recorded using a 64-channel EEG system to assess brain activity, while physical activity was recorded using an accelerometer at the lower back and a heart rate sensor. Source-space analysis was applied to analyze the power spectral density in theta (4 Hz–7 Hz) and alpha-2 (10 Hz–12 Hz) frequency bands. Vector magnitude was applied to the acceleration data.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Friedman ANOVA revealed significantly higher theta power for the exergaming conditions compared to the reference movement for both games. Alpha-2 power showed a more diverse pattern which might be attributed to task-specific conditions. Acceleration decreased significantly from the reference movement to the easy condition to the hard condition for both games.</jats:p></jats:sec><jats:sec><jats:title>Discussion</jats:title><jats:p>The results indicate that exergaming increases frontal theta activity irrespective of type of game or difficulty level, while physical activity decreases with increasing difficulty level. Heart rate was found to be an inappropriate measure in this population older adults. These findings contribute to understanding of how game characteristics affect physical and cognitive activity and consequently need to be taken into account when choosing appropriate games and game settings for exergame interventions.</jats:p></jats:sec>

<jats:p> Agility, a key component of team ball sports, describes an athlete´s ability to move fast in response to changing environments. While agility requires basic cognitive functions like processing speed, it also requires more complex cognitive processes like working memory and inhibition. Yet, most agility tests restrict an assessment of cognitive processes to simple reactive times that lack ecological validity. Our aim in this study was to assess agility performance by means of total time on two agility tests with matched motor demands but with both low and high cognitive demands. We tested 22 female team athletes on SpeedCourt, using a simple agility test (SAT) that measured only processing speed and a complex agility test (CAT) that required working memory and inhibition. We found excellent to good reliability for both our SAT (ICC = .79) and CAT (ICC =.70). Lower agility performance on the CAT was associated with increased agility total time and split times ( p &lt; .05). These results demonstrated that agility performance depends on the complexity of cognitive demands. There may be interference-effects between motor and cognitive performances, reducing speed when environmental information becomes more complex. Future studies should consider agility training models that implement complex cognitive stimuli to challenge athletes according to competitive demands. This will also allow scientists and practitioners to tailor tests to talent identification, performance development and injury rehabilitation. </jats:p>

<jats:p>Background: Medical professionals working in an elite sport environment have the challenging task to balance the athlete’s readiness to return to the playing field after severe injury with other stakeholders’ (coaches, sponsors, teammates) opinions and objectives.Objectives: Our study aimed to evaluate differences in the physical profiles of elite rugby players at return to play (RTP) after a severe knee injury, compared with their pre-injury profiles and matched controls.Method: Before the injury, participants performed four performance tests during their preseason screening. These tests were repeated and compared to baseline once a player was declared fit to play.Results: Significant differences (p ≤ 0.05) were found in the injured players’ group who were slower over 10 m speed, in their decision-making time and the total time of the reactive agility tests at RTP, whilst controls were significantly faster over 10 m and 30 m speed tests. The countermovement jump outcomes showed significant improvement in the uninjured participants (p ≤ 0.05).Conclusion: Our study highlights that injured players’ running speeds and decision-making times are slower after injury. The uninjured players have a positive outcome to training and match stimulus by improving their running speed and lower body explosive power during the season.Clinical implications: Our study provides insight into the RTP profile of elite rugby players, and a novel finding was the decision-making time deficit. This highlights the importance of cognitive training during injury rehabilitation as athletes make numerous decisions in a pressured and uncontrolled environment during a match. Speed training development is recommended as the athletes were slower after severe knee injury.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Coordinative challenging exercises in changing environments referred to as open-skill exercises seem to be beneficial on cognitive function. Although electroencephalographic research allows to investigate changes in cortical processing during movement, information about cortical dynamics during open-skill exercise is lacking. Therefore, the present study examines frontal brain activation during table tennis as an open-skill exercise compared to cycling exercise and a cognitive task. 21 healthy young adults conducted three blocks of table tennis, cycling and n-back task. Throughout the experiment, cortical activity was measured using 64-channel EEG system connected to a wireless amplifier. Cortical activity was analyzed calculating theta power (4–7.5 Hz) in frontocentral clusters revealed from independent component analysis. Repeated measures ANOVA was used to identify within subject differences between conditions (table tennis, cycling, n-back; <jats:italic>p</jats:italic> &lt; .05). ANOVA revealed main-effects of condition on theta power in frontal (<jats:italic>p</jats:italic> &lt; .01, <jats:italic>η</jats:italic><jats:sub>p</jats:sub><jats:sup>2</jats:sup> = 0.35) and frontocentral (<jats:italic>p</jats:italic> &lt; .01, <jats:italic>η</jats:italic><jats:sub>p</jats:sub><jats:sup>2</jats:sup> = 0.39) brain areas. Post-hoc tests revealed increased theta power in table tennis compared to cycling in frontal brain areas (<jats:italic>p</jats:italic> &lt; .05, <jats:italic>d</jats:italic> = 1.42). In frontocentral brain areas, theta power was significant higher in table tennis compared to cycling (<jats:italic>p</jats:italic> &lt; .01, <jats:italic>d</jats:italic> = 1.03) and table tennis compared to the cognitive task (<jats:italic>p</jats:italic> &lt; .01, <jats:italic>d</jats:italic> = 1.06). Increases in theta power during continuous table tennis may reflect the increased demands in perception and processing of environmental stimuli during open-skill exercise. This study provides important insights that support the beneficial effect of open-skill exercise on brain function and suggest that using open-skill exercise may serve as an intervention to induce activation of the frontal cortex.</jats:p>

<jats:title>Abstract</jats:title><jats:sec> <jats:title>Purpose</jats:title> <jats:p>Exhaustive cardiovascular load can affect neural processing and is associated with decreases in sensorimotor performance. The purpose of this study was to explore intensity-dependent modulations in brain network efficiency in response to treadmill running assessed from resting-state electroencephalography (EEG) measures.</jats:p> </jats:sec><jats:sec> <jats:title>Methods</jats:title> <jats:p>Sixteen trained participants were tested for individual peak oxygen uptake (VO<jats:sub>2 peak</jats:sub>) and performed an incremental treadmill exercise at 50% (10 min), 70% (10 min) and 90% speed VO<jats:sub>2 peak</jats:sub> (all-out) followed by cool-down running and active recovery. Before the experiment and after each stage, borg scale (BS), blood lactate concentration (B<jats:sub>La</jats:sub>), resting heartrate (HR<jats:sub>rest</jats:sub>) and 64-channel EEG resting state were assessed. To analyze network efficiency, graph theory was applied to derive small world index (SWI) from EEG data in theta, alpha-1 and alpha-2 frequency bands.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>Analysis of variance for repeated measures revealed significant main effects for intensity on BS, B<jats:sub>La</jats:sub>, HR<jats:sub>rest</jats:sub> and SWI. While BS, B<jats:sub>La</jats:sub> and HR<jats:sub>rest</jats:sub> indicated maxima after all-out, SWI showed a reduction in the theta network after all-out.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusion</jats:title> <jats:p>Our explorative approach suggests intensity-dependent modulations of resting-state brain networks, since exhaustive exercise temporarily reduces brain network efficiency. Resting-state network assessment may prospectively play a role in training monitoring by displaying the readiness and efficiency of the central nervous system in different training situations.</jats:p> </jats:sec>

<jats:title>Abstract </jats:title><jats:p>Mobile Electroencephalography (EEG) provides insights into cortical contributions to postural control. Although changes in theta (4–8 Hz) and alpha frequency power (8–12 Hz) were shown to reflect attentional and sensorimotor processing during balance tasks, information about the effect of stance leg on cortical processing related to postural control is lacking. Therefore, the aim was to examine patterns of cortical activity during single-leg stance with varying surface stability. EEG and force plate data from 21 healthy males (22.43 ± 2.23 years) was recorded during unipedal stance (left/right) on a stable and unstable surface. Using source-space analysis, power spectral density was analyzed in the theta, alpha-1 (8–10 Hz) and alpha-2 (10–12 Hz) frequency bands. Repeated measures ANOVA with the factors leg and surface stability revealed significant interaction effects in the left (<jats:italic>p</jats:italic> = 0.045, <jats:italic>η</jats:italic><jats:sub><jats:italic>p</jats:italic></jats:sub><jats:sup>2</jats:sup> = 0.13) and right motor clusters (<jats:italic>F</jats:italic> = 16.156; <jats:italic>p</jats:italic> = 0.001, <jats:italic>η</jats:italic><jats:sub><jats:italic>p</jats:italic></jats:sub><jats:sup>2</jats:sup> = 0.41). Furthermore, significant main effects for surface stability were observed for the fronto-central cluster (theta), left and right motor (alpha-1), as well as for the right parieto-occipital cluster (alpha-1/alpha-2). Leg dependent changes in alpha-2 power may indicate lateralized patterns of cortical processing in motor areas during single-leg stance. Future studies may therefore consider lateralized patterns of cortical activity for the interpretation of postural deficiencies in unilateral lower limb injuries.</jats:p>

<jats:p>Whereas initial findings have already identified cortical patterns accompanying proprioceptive deficiencies in patients after anterior cruciate ligament reconstruction (ACLR), little is known about compensatory sensorimotor mechanisms for re-establishing postural control. Therefore, the aim of the present study was to explore leg dependent patterns of cortical contributions to postural control in patients 6 weeks following ACLR. A total of 12 patients after ACLR (25.1 ± 3.2 years, 178.1 ± 9.7 cm, 77.5 ± 14.4 kg) and another 12 gender, age, and activity matched healthy controls participated in this study. All subjects performed 10 × 30 s. single leg stances on each leg, equipped with 64-channel mobile electroencephalography (EEG). Postural stability was quantified by area of sway and sway velocity. Estimations of the weighted phase lag index were conducted as a cortical measure of functional connectivity. The findings showed significant group × leg interactions for increased functional connectivity in the anterior cruciate ligament (ACL) injured leg, predominantly including fronto−parietal [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 8.41, <jats:italic>p</jats:italic> ≤ 0.008, η<jats:sup>2</jats:sup> = 0.28], fronto−occipital [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 4.43, <jats:italic>p</jats:italic> ≤ 0.047, η<jats:sup>2</jats:sup> = 0.17], parieto−motor [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 10.30, <jats:italic>p</jats:italic> ≤ 0.004, η<jats:sup>2</jats:sup> = 0.32], occipito−motor [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 5.21, <jats:italic>p</jats:italic> ≤ 0.032, η<jats:sup>2</jats:sup> = 0.19], and occipito−parietal [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 4.60, <jats:italic>p</jats:italic> ≤ 0.043, η<jats:sup>2</jats:sup> = 0.17] intra−hemispherical connections in the contralateral hemisphere and occipito−motor [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 7.33, <jats:italic>p</jats:italic> ≤ 0.013, η<jats:sup>2</jats:sup> = 0.25] on the ipsilateral hemisphere to the injured leg. Higher functional connectivity in patients after ACLR, attained by increased emphasis of functional connections incorporating the somatosensory and visual areas, may serve as a compensatory mechanism to control postural stability of the injured leg in the early phase of rehabilitation. These preliminary results may help to develop new neurophysiological assessments for detecting functional deficiencies after ACLR in the future.</jats:p>

<jats:title>Abstract</jats:title><jats:p>The interaction of acute exercise and the central nervous system evokes increasing interest in interdisciplinary research fields of neuroscience. Novel approaches allow to monitor large-scale brain networks from mobile electroencephalography (EEG) applying graph theory, but it is yet uncertain whether brain graphs extracted after exercise are reliable. We therefore aimed to investigate brain graph reliability extracted from resting state EEG data before and after submaximal exercise twice within one week in male participants. To obtain graph measures, we extracted global small-world-index (SWI), clustering coefficient (CC) and characteristic path length (PL) based on weighted phase leg index (wPLI) and spectral coherence (Coh) calculation. For reliability analysis, Intraclass-Correlation-Coefficient (ICC) and Coefficient of Variation (CoV) were computed for graph measures before (REST) and after POST) exercise. Overall results revealed poor to excellent measures at PRE and good to excellent ICCs at POST in the theta, alpha-1 and alpha-2, beta-1 and beta-2 frequency band. Based on bootstrap-analysis, a positive effect of exercise on reliability of wPLI based measures was observed, while exercise induced a negative effect on reliability of Coh-based graph measures. Findings indicate that brain graphs are a reliable tool to analyze brain networks in exercise contexts, which might be related to the neuroregulating effect of exercise inducing functional connections within the connectome. Relative and absolute reliability demonstrated good to excellent reliability after exercise. Chosen graph measures may not only allow analysis of acute, but also longitudinal studies in exercise-scientific contexts. </jats:p>

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Objective</jats:title> <jats:p>External focus (EF) of attention leads to improved balance performance. Consideration of the neuromodulatory effects of EF may inform its clinical utility in addressing neuroplastic impairments after musculoskeletal injuries. We aimed to determine whether electrocortical activity and balance performance changed with attentional foci that prioritized differing sensory feedback and whether changes in electrocortical activity and balance were associated.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Individuals who were healthy (n = 15) performed a single-limb balance task under 3 conditions: internal focus (IF), somatosensory focus [EF with a baton (EF-baton)], and visual focus [EF with a laser (EF-laser)]. Electrocortical activity and postural sway were recorded concurrently using electroencephalography and a triaxial force plate. Electroencephalographic signals were decomposed, localized, and clustered to generate power spectral density in θ and α-2 frequency bands. Postural sway signals were analyzed with center-of-pressure sway metrics (eg, area, distance, velocity) and knee angle. The relationship between percent change in clustered brain activity and task performance metrics was assessed.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Both EF conditions resulted in increased cortical activity and improved balance performance compared to IF. EF-laser had the largest effect, demonstrating increased frontal θ power (d = 0.64), decreased central θ power (d = −0.30), and decreased bilateral motor, bilateral parietal, and occipital α-2 power (d = −1.38 to −4.27) as well as a shorter path distance (d = −0.94) and a deeper (d = 0.70) and less variable (d = −1.15) knee angle than IF. Weak to moderate associations exist between increases in cortical activity and improved balance performance (ρ = 0.405–0.584).</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>EF resulted in increased cortical activity associated with cognitive, motor, somatosensory, and visual processing. EF-laser, which prioritized visual feedback, had the largest and broadest effects. Changes in cortical activity resulting from EF were independently associated with improved balance performance.</jats:p> </jats:sec> <jats:sec> <jats:title>Impact</jats:title> <jats:p>This study demonstrates that goal-oriented attention results in functional increases in brain activity compared to internally directed self-focus. These results suggest EF may target neurophysiologic impairments and improve balance in clinical populations.</jats:p> </jats:sec>

<jats:p>Whereas initial findings have already identified cortical patterns accompanying proprioceptive deficiencies in patients after anterior cruciate ligament reconstruction (ACLR), little is known about compensatory sensorimotor mechanisms for re-establishing postural control. Therefore, the aim of the present study was to explore leg dependent patterns of cortical contributions to postural control in patients 6 weeks following ACLR. A total of 12 patients after ACLR (25.1 ± 3.2 years, 178.1 ± 9.7 cm, 77.5 ± 14.4 kg) and another 12 gender, age, and activity matched healthy controls participated in this study. All subjects performed 10 × 30 s. single leg stances on each leg, equipped with 64-channel mobile electroencephalography (EEG). Postural stability was quantified by area of sway and sway velocity. Estimations of the weighted phase lag index were conducted as a cortical measure of functional connectivity. The findings showed significant group × leg interactions for increased functional connectivity in the anterior cruciate ligament (ACL) injured leg, predominantly including fronto−parietal [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 8.41, <jats:italic>p</jats:italic> ≤ 0.008, η<jats:sup>2</jats:sup> = 0.28], fronto−occipital [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 4.43, <jats:italic>p</jats:italic> ≤ 0.047, η<jats:sup>2</jats:sup> = 0.17], parieto−motor [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 10.30, <jats:italic>p</jats:italic> ≤ 0.004, η<jats:sup>2</jats:sup> = 0.32], occipito−motor [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 5.21, <jats:italic>p</jats:italic> ≤ 0.032, η<jats:sup>2</jats:sup> = 0.19], and occipito−parietal [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 4.60, <jats:italic>p</jats:italic> ≤ 0.043, η<jats:sup>2</jats:sup> = 0.17] intra−hemispherical connections in the contralateral hemisphere and occipito−motor [<jats:italic>F</jats:italic><jats:sub>(1, 22)</jats:sub> = 7.33, <jats:italic>p</jats:italic> ≤ 0.013, η<jats:sup>2</jats:sup> = 0.25] on the ipsilateral hemisphere to the injured leg. Higher functional connectivity in patients after ACLR, attained by increased emphasis of functional connections incorporating the somatosensory and visual areas, may serve as a compensatory mechanism to control postural stability of the injured leg in the early phase of rehabilitation. These preliminary results may help to develop new neurophysiological assessments for detecting functional deficiencies after ACLR in the future.</jats:p>

<jats:title>Abstract </jats:title><jats:p>Mobile Electroencephalography (EEG) provides insights into cortical contributions to postural control. Although changes in theta (4–8 Hz) and alpha frequency power (8–12 Hz) were shown to reflect attentional and sensorimotor processing during balance tasks, information about the effect of stance leg on cortical processing related to postural control is lacking. Therefore, the aim was to examine patterns of cortical activity during single-leg stance with varying surface stability. EEG and force plate data from 21 healthy males (22.43 ± 2.23 years) was recorded during unipedal stance (left/right) on a stable and unstable surface. Using source-space analysis, power spectral density was analyzed in the theta, alpha-1 (8–10 Hz) and alpha-2 (10–12 Hz) frequency bands. Repeated measures ANOVA with the factors leg and surface stability revealed significant interaction effects in the left (<jats:italic>p</jats:italic> = 0.045, <jats:italic>η</jats:italic><jats:sub><jats:italic>p</jats:italic></jats:sub><jats:sup>2</jats:sup> = 0.13) and right motor clusters (<jats:italic>F</jats:italic> = 16.156; <jats:italic>p</jats:italic> = 0.001, <jats:italic>η</jats:italic><jats:sub><jats:italic>p</jats:italic></jats:sub><jats:sup>2</jats:sup> = 0.41). Furthermore, significant main effects for surface stability were observed for the fronto-central cluster (theta), left and right motor (alpha-1), as well as for the right parieto-occipital cluster (alpha-1/alpha-2). Leg dependent changes in alpha-2 power may indicate lateralized patterns of cortical processing in motor areas during single-leg stance. Future studies may therefore consider lateralized patterns of cortical activity for the interpretation of postural deficiencies in unilateral lower limb injuries.</jats:p>

Advances in EEG filtering algorithms enable analysis of EEG recorded during motor tasks. Although methods such as artifact subspace reconstruction (ASR) can remove transient artifacts automatically, there is virtually no knowledge about how the vigor of bodily movements affects ASRs performance and optimal cut-off parameter selection process. We compared the ratios of removed and reconstructed EEG recorded during a cognitive task, single-leg stance, and fast walking using ASR with 10 cut-off parameters versus visual inspection. Furthermore, we used the repeatability and dipolarity of independent components to assess their quality and an automatic classification tool to assess the number of brain-related independent components. The cut-off parameter equivalent to the ratio of EEG removed in manual cleaning was strictest for the walking task. The quality index of independent components, calculated using RELICA, reached a maximum plateau for cut-off parameters of 10 and higher across all tasks while dipolarity was largely unaffected. The number of independent components within each task remained constant, regardless of the cut-off parameter used. Surprisingly, ASR performed better in motor tasks compared with non-movement tasks. The quality index seemed to be more sensitive to changes induced by ASR compared to dipolarity. There was no benefit of using cut-off parameters less than 10.</jats:p>

<jats:p><jats:italic><jats:bold>Purpose</jats:bold>:</jats:italic> Whereas many studies addressed the relation between acute physical exercise and executive functions (EF) in children, the effects of various modalities of acute exercise on EF still remain unclear. This systematic review investigated the effects of exercise with low and high cognitive demands on speed of processing and accuracy of performance in tasks examining inhibition, working memory, and cognitive flexibility in children. <jats:italic><jats:bold>Method</jats:bold>:</jats:italic> A systematic literature research in electronic databases was performed. Controlled trials assessing the effects of acute exercise on EF in a pre–post design were included. <jats:italic><jats:bold>Results</jats:bold>:</jats:italic> Ten studies involving a total of 890 participants revealed positive effects in working memory performance in speed of processing after acute exercises with low cognitive demands compared with seated rest, mixed results for inhibition after exercises with low and high cognitive demands, and mixed results for cognitive flexibility with low cognitive demands. Concerning accuracy, only mixed results were found for inhibition after exercises with low and high cognitive demands. <jats:italic><jats:bold>Conclusion</jats:bold>:</jats:italic> The differentiated effects of acute exercises with low and high cognitive demands led to more positive effects in speed of processing compared with accuracy of performance. Further investigations including assessment of neurophysiological parameters of EF are needed.</jats:p>