Dynamics and moderating factors of esport participation and loneliness: A daily diary study.

The purpose of this study was to examine the association between esport participation and loneliness, as well as its moderating factors. Chinese college students (N = 216) self-reported their esport playing time and degree of loneliness each day immediately before bedtime for four consecutive weeks. The findings revealed that as playing time increased, students did not experience reduced sense of loneliness during playing esport, but they experienced a temporary and intensified feeling of loneliness the same day following gameplay. Students with higher general loneliness tended to feel more after-game loneliness associated with increased esport participation. Students with higher obsessive passion about esport tended to experience more loneliness (both in-game and after-game) associated with increased esport participation. Students with greater coping motivation about esport tended to experience more in-game loneliness associated with previous increased esport participation. Students who played esport less often with friends in person, or with more escape motivation toward esport, tended to increase esport participation time more following previous increased after-game loneliness. The findings suggested that college students should avoid utilizing esport to achieve a sense of belonging and should be cautious of the loneliness-inducing effect after gameplay. A healthy level of loneliness can be maintained by playing esport more with friends in person, learning strategies to avoid obsessive passion, coping motivation, and escape motivation towards esport.

Acute cardiovascular responses to unilateral bicep curls with blood flow restriction.

A consensus on the acute cardiovascular responses to low intensity (LI) resistance exercise (RE) combined with blood flow restriction (BFR) has not yet been reached. This study was designed to compare acute cardiovascular responses to a single bout of LIRE, high intensity (HI) RE, and LIRE with BFR in physically active young males. Participants completed 3 RE sessions in random order, where each session consists of 4 sets of unilateral dumbbell bicep curls. Cardiovascular hemodynamics were measured at baseline and right after each set of RE. Aortic augmentation index (AIx) was significantly higher after set 2,3,4 of RE in LI + BFR session compared to LI session (P < 0.05). Brachial systolic blood pressure (SBP), heart rate (HR), brachial rate pressure product (RPP), and central RPP responses did not differ between LI and LI + BFR sessions (P > 0.05). HI session had a higher central SBP, brachial RPP, central RPP, and aortic AIx compared to LI session after each set of RE (P < 0.05), but not brachial SBP (P > 0.05). Taken together, this study showed that LIRE combined with BFR acutely augmented aortic stiffness, as also observed in HI session, but myocardial oxygen consumption was only higher in HI session when compared to LI session. Thus, although BFR did not exaggerate cardiovascular responses nor cause extra myocardial oxygen consumption, it should be prescribed with caution when control of acute aortic stiffening is necessary during RE.

Is Increased Video Game Participation Associated With Reduced Sense of Loneliness? A Systematic Review and Meta-Analysis.

The purpose of this systematic review was to evaluate the existing evidence in literature addressing the relationship between video game participation and loneliness. The following databases were searched on October 2, 2021: Medline, Psychinfo, SportDiscus, Web of Science, and CINAHL. The risk of bias of cross-sectional study was assessed by using the Joanna Briggs Institute (JBI) critical appraisal checklist for analytical cross-sectional studies with attrition bias added for longitudinal studies. The results of all included studies were synthesized using narrative synthesis. Meta-analysis was utilized to synthesis the findings of the studies that had sufficient degree of statistical and methodological homogeneity. Eighteen studies were included in this systematic review, which comprised of 20,372 participants. The narrative synthesis showed mixed findings on the relationship between video game participation and loneliness. Meta-analysis that was conducted to nine cross-sectional studies revealed that video game participation was positively and weakly associated with loneliness (r = 0.10, 95% CI = 0.03-0.17). Both cross-sectional and longitudinal studies demonstrated serious risk of bias with the addition of serious inconsistency of findings from cross-sectional studies. The existing literature is equivocal in terms of making a definitive judgment on the association between video game participation and loneliness. PROSPERO registration number: CRD42021283025. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42021283025.

Correspondence and Concordance of Retrospective and Concurrent Responses to Physiotherapists and Sport Psychology Questionnaire Items.

Orthopedic and sport-related injuries are a major public health concern and a common reason for referral to physical therapy. The use of psychological techniques by physical therapists has been assessed in research studies primarily with retrospective self-report questionnaires that have not been validated against concurrent assessments of the same behaviors. The primary purpose of this study was to examine the extent to which the results obtained from physical therapists' retrospective self-reports of their use of psychological techniques reflect their use of the techniques assessed concurrently. Physical therapists (N = 14) completed the Physiotherapists and Sport Psychology Questionnaire (PSPQ) at the beginning of this study and a checklist based on the PSPQ at the end of the sessions with patients (N = 306). Patients also completed the checklist at the end of the sessions. Across 12 psychological techniques, the physical therapists' retrospective (PSPQ) responses showed relatively weak correspondence (mean r = 0.31) and poor concordance with their concurrent (checklist) responses. Compared to the physical therapists' checklist responses, the patients' checklist responses showed weaker correspondence (mean r = 0.03) and better concordance with the physical therapists' PSPQ responses. The findings suggest that retrospective self-reports may not accurately reflect the use of psychological techniques by physical therapists and, consequently, that physical therapists should consider documenting their use of psychological techniques as close to their implementation as possible. Suggestions for improved assessment are provided.

Effectiveness of Warm-Up Intervention Programs to Prevent Sports Injuries among Children and Adolescents: A Systematic Review and Meta-Analysis.

Sports participation by children and adolescents often results in injuries. Therefore, injury prevention warm-up programs are imperative for youth sports safety. The purpose of this paper was to assess the effectiveness of Warm-up Intervention Programs (WIP) on upper and lower limb sports injuries through a systematic review and meta-analysis. Searches for relevant studies were performed on PubMed, EMBASE, Web of Science, SPORTDiscus, and Cochrane databases. Studies selected met the following criteria: original data; analytic prospective design; investigated a WIP and included outcomes for injury sustained during sports participation. Two authors assessed the quality of evidence using Furlan's criteria. Comprehensive Meta-Analysis 3.3 software was used to process and analyze the outcome indicators of the literature. Across fifteen studies, the pooled point estimated injury rate ratio (IRR) was 0.64 (95% CI = 0.54−0.75; 36% reduction) while accounting for hours of risk exposure. Publication bias assessment suggested a 6% reduction in the estimate (IRR = 0.70, 95% CI = 0.60−0.82), and the prediction interval intimated that any study estimate could still fall between 0.34 and 1.19. Subgroup analyses identified one significant moderator that existed in the subgroup of compliance (p < 0.01) and might be the source of heterogeneity. Compared with the control group, WIPs significantly reduced the injury rate ratio of upper and lower limb sports injuries in children and adolescents.

Corrigendum: Neural Efficiency in Athletes: A Systematic Review.

[This corrects the article DOI: 10.3389/fnbeh.2021.698555.].

Neural Efficiency in Athletes: A Systematic Review.

According to the neural efficiency hypothesis (NEH), professionals have more effective cortical functions in cognitive tasks. This study is focusing on providing a systematic review of sport-related NEH studies with functional neuroimaging or brain stimulation while performing a sport-specific task, with the aim to answer the question: How does long-term specialized training change an athlete's brain and improve efficiency? A total of 28 studies (N = 829, Experimental Group n = 430) from 2001 to 2020 (Median = 2014, SD = 5.43) were analyzed and results were organized into four different sections: expert-novice samples, perceptual-cognitive tasks and neuroimaging technologies, efficiency paradox, and the cluster analysis. Researchers examined a wide range of sport-specific videos and multiple object tracking (MOT) specific to 18 different sports and utilized blood oxygenation-level dependent (BOLD) functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), and electroencephalogram (EEG). Expert-novice comparisons were often adopted into investigations about the variations in general about optimal-controlled performance, neurophysiology, and behavioral brain research. Experts tended to perform at faster speeds, more accurate motor behavior, and with greater efficiency than novices. Experts report lower activity levels in the sensory and motor cortex with less energy expenditure, experts will possibly be more productive. These findings generally supported the NEH across the studies reviewed. However, an efficiency paradox and proficient brain functioning were revealed as the complementary hypothesis of the NEH. The discussion concentrates on strengths and key limitations. The conclusion highlights additional concerns and recommendations for prospective researchers aiming to investigate a broader range of populations and sports.

Pursuing Collective Synchrony in Teams: A Regime-Switching Dynamic Factor Model of Speed Similarity in Soccer.

Collective synchrony refers to the simultaneous occurrence of behavior, cognition, emotion, and/or physiology within teams of three or more persons. It has been suggested that collective synchrony may emanate from the copresence of team members, from their engagement in a shared task, and from coordination enacted in pursuit of a collective goal. In this paper, a regime-switching dynamic factor analytical approach is used to examine interindividual similarities in a particular behavioral measure (i.e., speed) in a collegiate soccer team. First, the analytical approach is presented didactically, including the state space modeling framework in general, followed by the regime-switching dynamic factor model in particular. Next, an empirical application of the approach is presented. Speed similarity (covariation in speed, operationalized in two ways: running cadence and distance covered) during competitive women's soccer games is examined. A key methodological aspect of the approach is that the collective is the unit of analysis, and individuals vary about collective dynamics and their evolution. Reporting on the results of this study, we show how features of substantive interest, such as the magnitude and prevalence of behavioral similarity, can be parameterized, interpreted, and aggregated. Finally, we highlight several key findings, as well as opportunities for future research, in terms of methodological and substantive aims for advancing the study of collective synchrony.

The Effects of a 10-Week Neuromuscular Training on Postural Control in Elite Youth Competitive Ballroom Dancers: A Randomized Controlled Trial.

The purpose of this randomized controlled trial was to evaluate the efficacy of a 10-week neuromuscular training (NMT) program on the postural control of elite youth competitive ballroom dancers. Forty-two dancers (21 couples) were randomly assigned to either the NMT group (n = 22) or the control group (CG; n = 20). Participants in NMT underwent a three-sessions-per-week NMT program for 10 weeks. Testing at baseline and after the 10 weeks intervention included the Y-balance test (YBT) and Modified-Balance Error Scoring System (M-BESS). Results of YBT indicated that NMT participants demonstrated increased reach in the posterolateral and posteromedial directions for the right and left lower limb, whereas no significant change was found in the anterior direction for both limbs. Results of Modified-Balance Error Scoring System (M-BESS) showed that NMT participants displayed significantly decreased errors of the double-leg floor (p = 0.026), single-leg foam (p = 0.010), double-leg foam (p = 0.003), tandem floor (p = 0.031), and tandem foam (p = 0.038), while no significant change was found in single-leg floor performance (p = 0.476). CG participants did not exhibit any significant change during the 10-week period. In summary, the study affirmed that the 10-week NMT program enhanced the postural control performance of youth ballroom dancers and showed effects on ballroom dance-specific performance and lower-limb injury prevention. The results suggest that NMT may be a valuable addition to ballroom dance training regimens.

Chronic Physical Activity for Attention Deficit Hyperactivity Disorder and/or Autism Spectrum Disorder in Children: A Meta-Analysis of Randomized Controlled Trials.

Purpose: To explore the effects of physical activity (PA) intervention on executive function (EF) and motor skills (MS) among children with attention deficit hyperactivity disorder and/or autism spectrum disorder (ASD). Methods: Relevant studies were sourced from PubMed, Web of Science, EMBASE, Cochrane Library, CNKI and Wanfang Data. Only randomized controlled trials (RCT) were included based upon the following criteria: (1) participants were children and clinically diagnosed with ADHD/ASD, (2) intervention strategies were identified as chronic physical activity, and (3) EF (e.g., cognitive flexibility) and/or MS (e.g., gross motor skills) were measured at baseline and post-intervention and compared with an eligible control group. Results: Eleven studies involving 346 participants were finally identified. PA elicited significant improvements in EF and MS in children with ADHD/ASD. Regarding changes in the EF of participants, PA showed a great improvement in overall EF [standardized mean difference (SMD): 0.90, 95% confidence interval (CI) 0.49-1.30, p < 0.00001], inhibitory control (SMD: 1.30, 95% CI 0.58-2.02, p = 0.0004) and cognitive flexibility (SMD: 0.85, 95% CI 0.42-1.29, p = 0.0001), but no significant improvement in working memory (SMD: 0.28, 95% CI -0.15-0.71, p = 0.20). Significant improvements were also found with respect to gross motor skills (SMD: 0.80, 95% CI 0.30-1.30, p = 0.002), but no significant changes were found in fine motor skills (SMD: 0.30, 95% CI -0.91-1.52, p = 0.62). Conclusion: Chronic PA interventions may promote EF and MS in children with ADHD/ASD, especially in inhibitory control, cognitive flexibility, and gross motor skills. However, PA interventions seemed to have insignificant effects on working memory and fine motor skills to children with ADHD/ASD. PROSPERO registration number: CRD42019118622.

Effects of kinematic complexity and number of muscles on musculoskeletal model robustness to muscle dysfunction.

The robustness of motor outputs to muscle dysfunction has been investigated using musculoskeletal modeling, but with conflicting results owing to differences in model complexity and motor tasks. Our objective was to systematically study how the number of kinematic degrees of freedom, and the number of independent muscle actuators alter the robustness of motor output to muscle dysfunction. We took a detailed musculoskeletal model of the human leg and systematically varied the model complexity to create six models with either 3 or 7 kinematic degrees of freedom and either 14, 26, or 43 muscle actuators. We tested the redundancy of each model by quantifying the reduction in sagittal plane feasible force set area when a single muscle was removed. The robustness of feasible force set area to the loss of any single muscle, i.e. general single muscle loss increased with the number of independent muscles and decreased with the number of kinematic degrees of freedom, with the robust area varying from 1% and 52% of the intact feasible force set area. The maximum sensitivity of the feasible force set to the loss of any single muscle varied from 75% to 26% of the intact feasible force set area as the number of muscles increased. Additionally, the ranges of feasible muscle activation for maximum force production were largely unconstrained in many cases, indicating ample musculoskeletal redundancy even for maximal forces. We propose that ratio of muscles to kinematic degrees of freedom can be used as a rule of thumb for estimating musculoskeletal redundancy in both simulated and real biomechanical systems.

Frontline Science: High fat diet and leptin promote tumor progression by inducing myeloid-derived suppressor cells.

Obesity is a risk factor for cancer incidence and cancer mortality. The association of obesity and cancer is attributed to multiple factors, but the tightest linkage is with the chronic, low-grade inflammation that accompanies obesity. Myeloid-derived suppressor cells (MDSC) are known facilitators of cancer progression that act by suppressing the activation and function of tumor-reactive T cells. Because MDSC quantity and function are driven by chronic inflammation, we hypothesized that MDSC may accumulate in obese individuals and facilitate tumor growth by suppressing antitumor immunity. To test this hypothesis, tumor-bearing mice on a high fat or low fat diet (HFD or LFD) were assessed for tumor progression and the metabolic dysfunction associated with obesity. HFD enhanced the accumulation of MDSC, and the resulting MDSC had both beneficial and detrimental effects. HFD-induced MDSC protected mice against diet-induced metabolic dysfunction and reduced HFD-associated inflammation, but also increased the accumulation of fat, enhanced tumor progression, and spontaneous metastasis and reduced survival time. HFD-induced MDSC facilitated tumor growth by limiting the activation of tumor-reactive CD8+ T cells. Leptin, an adipokine that regulates appetite satiety and is overexpressed in obesity, undergoes crosstalk with MDSC in which leptin drives the accumulation of MDSC while MDSC down-regulate the production of leptin. Collectively, these studies demonstrate that although MDSC protect against some metabolic dysfunction associated with HFD they enhance tumor growth in HFD mice and that leptin is a key regulator linking HFD, chronic inflammation, immune suppression, and tumor progression.

Bivariate autoregressive state-space modeling of psychophysiological time series data.

Heart rate (HR) and electrodermal activity (EDA) are often used as physiological measures of psychological arousal in various neuropsychology experiments. In this exploratory study, we analyze HR and EDA data collected from four participants, each with a history of suicidal tendencies, during a cognitive task known as the Paced Auditory Serial Addition Test (PASAT). A central aim of this investigation is to guide future research by assessing heterogeneity in the population of individuals with suicidal tendencies. Using a state-space modeling approach to time series analysis, we evaluate the effect of an exogenous input, i.e., the stimulus presentation rate which was increased systematically during the experimental task. Participants differed in several parameters characterizing the way in which psychological arousal was experienced during the task. Increasing the stimulus presentation rate was associated with an increase in EDA in participants 2 and 4. The effect on HR was positive for participant 2 and negative for participants 3 and 4. We discuss future directions in light of the heterogeneity in the population indicated by these findings.

Neurophysiology of action anticipation in athletes: A systematic review.

The purpose of this study was to provide a systematic review of action anticipation studies using functional neuroimaging or brain stimulation during a sport-specific anticipation task. A total of 15 studies from 2008 to 2014 were evaluated and are reported in four sections: expert-novice samples, action anticipation tasks, neuroimaging and stimulation techniques, and key findings. Investigators examined a wide range of action anticipation scenarios specific to eight different sports and utilized functional magnetic resonance imaging (fMRI), electroencephalogram (EEG), and transcranial magnetic stimulation (TMS). Expert-novice comparisons were commonly used to investigate differences in action anticipation performance and neurophysiology. Experts tended to outperform novices, and an extensive array of brain structures were reported to be involved differently for experts and novices during action anticipation. However, these neurophysiological findings were generally inconsistent across the studies reviewed. The discussion focuses on strengths and four key limitations. The conclusion posits remaining questions and recommendations for future research.