Characteristics of injuries related to Kin-Ball sport in Japan: A questionnaire study.

INTRODUCTION: The number of Kin-Ball sport participants is expected to increase in the future. However, there is no report on the characteristics of the injuries associated with Kin-Ball sport. OBJECTIVE: The purpose of this study was to describe the characteristics of injuries relate to Kin-Ball sport. DESIGN: Observational study. SETTING: A self-administered questionnaire was used for data collection. PARTICIPANTS: One hundred ninety Kin-Ball sport participants were included in this study. MAIN OUTCOME MEASURES: The questionnaire was designed based on physical characteristics, participation in Kin-Ball sport, and Kin-Ball sport injuries. Participation in Kin-Ball sport includes the length of time spent playing Kin-Ball sport as well as the playing categories (junior, friendly, champion challenge, champion, over 40). Kin-Ball sport injuries include the presence or absence of injury experience, the site, type, situation, and current injuries or pain associated with Kin-Ball sport. RESULTS: One hundred fifty-two players (80%) of Kin-Ball sport participants were injured. The ankle was the most frequently visited body site (60; 22.1%), and the elbow was the second most visited body site (40; 14.8%). Sprains were the most common type of injury. CONCLUSION: This is the first study to describe the characteristics of injuries relate to Kin-Ball sport. The findings of this study could be beneficial for athletes, coaches, trainers, and clinicians to prevent, or treatment of the injuries.

Differences in Electroencephalography Power Levels between Poor and Good Performance in Attentional Tasks.

Decreased attentional function causes problems in daily life. However, a quick and easy evaluation method of attentional function has not yet been developed. Therefore, we are searching for a method to evaluate attentional function easily and quickly. This study aimed to collect basic data on the features of electroencephalography (EEG) during attention tasks to develop a new method for evaluating attentional function using EEG. Twenty healthy young adults participated; we examined cerebral activity during a Clinical Assessment for Attention using portable EEG devices. The Mann-Whitney U test was performed to assess differences in power levels of EEG during tasks between the low- and high-attention groups. The findings revealed that the high-attention group showed significantly higher EEG power levels in the δ wave of L-temporal and bilateral parietal lobes, as well as in the ß and γ waves of the R-occipital lobe, than did the low-attention group during digit-forward, whereas the high-attention group showed significantly higher EEG power levels in the θ wave of R-frontal and the α wave of bilateral frontal lobes during digit-backward. Notably, lower θ, α, and ß bands of the right hemisphere found in the low-attention group may be key elements to detect attentional deficit.

Assessing attentional task-related electroencephalogram signal variations by using mobile electroencephalogram technology: An experimental study.

BACKGROUND: A better understanding of the network responses of cortical activities during rest and cognitive tasks is necessary. Therefore, in this study, we aimed to evaluate cerebral activities during attentional tasks by using mobile electroencephalography, identifying the types of attentional components and brain waves. METHODS: In this experimental study, we enrolled 12 healthy young adults. The attentional tasks comprised parts A and B of the Trail-Making Test (TMT). Nineteen electroencephalography electrodes were placed over various brain regions. The Wilcoxon signed-rank test was used to examine the differences in power levels between the rest and TMT conditions. RESULTS: During TMT part A, the electroencephalography power level of the delta waves was significantly higher in the right frontal, left central, left occipital, left inferior frontal, right mid-temporal, right posterior temporal, and middle parietal areas (P < .05) than those during the resting state; that of the alpha waves was significantly lower in the left posterior temporal area (P = .006); and that of the high gamma waves was significantly lower in the left parietal (P = .05) and left occipital (P = .002) areas. During TMT part B, the electroencephalography power level of the beta waves was significantly higher in the right frontal area (P = .041) than that during the resting state, and that of the low gamma waves was significantly higher in the left frontal pole, right frontal, and right inferior frontal areas (P < .05). During the focused attentional task, the power level of the delta waves increased and that of the alpha waves decreased, and during the alternating attentional task, those of both the beta and gamma waves increased. The delta waves were related to the whole brain, the alpha and high gamma waves to the left posterior lobe, and the beta and low gamma waves to both frontal lobes. CONCLUSION: These findings contribute to the basic knowledge necessary to develop new attentional assessment methods for clinical situations.

An effective salivation-facilitating method for COVID-19 testing: An experimental study.

BACKGROUND: Simple tools, such as antigen test kits, are readily available for determining coronavirus disease 2019 infection at hospitals and homes. However, it is challenging for elderly people who are prone to dry mouth and other diseases. The main objective of this study was to investigate whether the presence or consumption of a plum pickle can facilitate salivation during coronavirus disease 2019 testing. METHOD: Twenty healthy adult women participated in the study. The participants were allocated to 2 groups: presentation and non-presentation (n = 10; with and without presentation of a plum pickle, respectively), and eating and non-eating (n = 10; with and without consumption of plum pickle, respectively). We recorded the number of saliva swallows in 1 minute under each condition, using a swallowing test device, which attached film sensors to the hyoid bone and thyroid cartilage. RESULTS: There was a significant difference in the number of swallows between the non-presentation and presentation groups ( P < .01, r = 0.89, Z = -2.82) as well as between the non-eating and eating groups ( P < .01, r = 0.85, Z = -2.68). CONCLUSIONS: The strength of 3 factors, namely: direct stimulation with citric acid, saliva buffer capacity, and motor learning, may have affected the results. Our study suggests that saliva collection using the plum pickle is an effective complementary method for facilitating salivation. This technique may be useful in avoiding the risk associated with citric acid intake and for efficient specimen collection during coronavirus disease 2019 testing. In the future, we need to verify this method in elderly participants in a clinical setting.

The Association between Party Horn Use and Respiratory Function in Patients with Dementia: An Experimental Study.

Background and Objectives: Respiratory diseases account for 55.5% and 33.1% of all mortality rates in patients with Alzheimer's disease and vascular dementia, respectively. However, the widespread use of spirometers is often difficult due to challenges in performing the procedure. Therefore, the use of spirometers is usually unfeasible in patients with dementia and hinders the provision of preventive measures for aspiration pneumonia. The party horn is a common toy in many countries and can potentially be used as a novel tool. This study was conducted to analyze the usefulness of the party horn as an assessment tool for respiratory function, and to detect eating-related behavioral problems in patients with dementia. Materials and Methods: A total of 62 inpatient participants with dementia (34 males, 28 females; age, mean ± SD, 80.4 ± 7.59 years) were included in the study. The respiratory functions of patients were assessed using a party horn and a spirometer. Assessment items pertaining to cognitive function, mental and behavioral disorders, eating-related behavioral problems, and the required dietary modifications were evaluated to compare between patient groups stratified by respiratory function. Results: Significant differences between groups were noted in length of hospital stay, cognitive functions, mental and behavioral disorders, eating-related behavioral problems, and dietary modifications. Forced expiratory volume in 1 s, peak expiratory flow, and eating-related behavioral problems were significantly associated with the party-horn-integrated value (p < 0.05). Conclusions: Party-horn-based evaluation can facilitate the screening and evaluation of older dementia patients for eating-related behavioral problems and aspiration risk.

Diagnostic model for preschool workers' unwillingness to continue working: Developed using machine-learning techniques.

The turnover of kindergarten teachers has drastically increased in the past 10 years. Reducing the turnover rates among preschool workers has become an important issue worldwide. Parents have avoided enrolling children in preschools due to insufficient care, which affects their ability to work. Therefore, this study developed a diagnostic model to understand preschool workers' unwillingness to continue working. A total of 1002 full-time preschool workers were divided into 2 groups. Predictors were drawn from general questionnaires, including those for mental health. We compared 3 algorithms: the least absolute shrinkage and selection operator, eXtreme Gradient Boosting, and logistic regression. Additionally, the SHapley Additive exPlanation was used to visualize the relationship between years of work experience and intention to continue working. The logistic regression model was adopted as the diagnostic model, and the predictors were "not living with children," "human relation problems with boss," "high risk of mental distress," and "work experience." The developed risk score and the optimal cutoff value were 14 points. By using the diagnostic model to determine workers' unwillingness to continue working, supervisors can intervene with workers who are experiencing difficulties at work and can help resolve their problems.

Factors affecting the mental health of medical students during the COVID-19 pandemic: A cross-sectional study.

The coronavirus disease 2019 outbreak has impacted many educational institutions by imposing restrictions on offline or in-person lessons. Many students were stressed by "the loss of everyday life" due to the pandemic, and it is important to examine the impact of this loss on adolescents' mental health. This study aimed to investigate the factors that affect students' mental health during the pandemic from various perspectives. A total of 166 medical students participated in this study. Participants completed questionnaires about their demographics, life stress, mental health, and stress factors during in-person and online lecture days. Participants were divided into 2 groups, those with low and high mental health. The researchers compared independent variables between the groups using the χ2 test or Fisher's exact test. Multiple logistic regression analysis was performed, with mental health as the dependent variable. The multiple logistic regression analysis indicated that increased time spent online was significantly associated with mental health (P < .05). Human relations and the inability to meet/talk with friends trended toward a significant association with mental health (P < .1). The students who were not stressed about the increased time spent online were at a risk of low mental health. The students who appreciated interacting with others experienced more stress during the lockdown. To reduce students' stress on online days, teachers should devise a lecture style with frequent breaks and introduce active learning. The findings of this study will contribute to addressing students' low mental health and reducing their stress during the coronavirus disease 2019 pandemic.

The relationship between scapular position and glenohumeral rotational range of motion in high school baseball players.

BACKGROUND: Past research indicated that scapular malposition is related to the glenohumeral internal rotation deficit (GIRD). However, there is no research examining the effect of throwing-related pain on this relationship. This study investigated the relationship between scapular position and range of motion (ROM) and compared the difference in this relationship between with and without throwing-related pain. METHODS: Forty male baseball players in high school were recruited for this study. The existence and degree of throwing-related pain were obtained from a questionnaire. Participants were divided into 2 groups according to the presence or absence of the pain. Glenohumeral internal and external rotation ROM (abduction internal rotation angle and abduction external rotation angle [ABER], respectively) were measured using a digital inclinometer. The pectoralis minor muscle length was measured using a vernier caliper and scapula index, which indicated the scapular position, measured using a measuring tape. All these measurements were taken on both dominant and nondominant sides. The GIRD and total motion arc (TMA) deficit were calculated from the ROM measurements. Groups were compared using a mixed-model analysis of variance. RESULTS: There was a significant interaction between group and ABER dominance. Other variables were not seen as the interaction effect. There was a significant positive correlation between the scapula index and TMA (r = 0.47, P = .02) and a negative correlation between the scapula index and GIRD (r = -0.65, P < .01) in the dominant side of the pain group. In addition, in the nondominant side of the pain group, the scapula index and ABER were significantly correlated (r = 0.43, P = .04). CONCLUSIONS: The results of this study indicate that the scapular position is associated with the glenohumeral ROM in high school baseball players. In addition, this study demonstrated that the scapular internally rotated position was correlated with the GIRD and TMA deficit in high school baseball players who had throwing-related pain. On the other hand, the scapular externally rotated position was correlated with increased ABER, mainly in the pain-free baseball players or on the nondominant side. These results indicated that the scapular position might affect the glenohumeral rotational ROM in high school baseball players.

Why Do They Leave? The Counterplans to Continue Working among Preschool Workers in Japan: A Cross-Sectional Survey.

Three institutions predominantly care for preschool children in Japan: kindergartens, authorized childcare institutions, and nursery centers. Recently, the turnover rates of preschool workers in these institutions have been high, and Japan has been facing a shortage of kindergarten teachers. The study aimed to provide concrete counterplans to reduce preschool workers' turnover rate. To determine the causes of turnover, we conducted a cross-sectional survey. We recruited preschool workers from several kindergartens, authorized childcare institutions, and nursery centers in Japan to fill out a survey regarding counterplans for employment. Of the 1002 surveys, 551 (541 women; 10 men) complete surveys were received (response rate: 55%). A total of 295 participants answered that they were unwilling to continue working for longer than five years and completed the questionnaires. The Jiro Kawakita method was used to categorize and analyze the four sections of the counterplan questionnaires. The results showed that the main reasons for high turnover were overtime work, low salary, and difficult human relations. To solve these issues, the counterplan ideas such as workshop ideas and conditions conducive to continuing working longer were related to human relations, work conditions, and mental health.

Factors associated with kindergarten teachers' willingness to continue working.

ABSTRACT: The turnover rate among kindergarten teachers in advanced countries is extremely high. As such, there is an urgent need to determine the reasons for this turnover and to identify ways to prevent it. The current study investigates the individual and environmental factors that impact kindergarten teachers' willingness to continue working.A total of 600 kindergarten teachers in Japan participated in this study. Participants responded to questionnaires regarding their willingness to continue working, mental health, work engagement, and the availability of social support. Multiple logistic regression analysis was used to analyze participants' data, with willingness to continue working for 5 or more years as the dependent variable. Additionally, Spearman rank correlation was used to examine the correlations between factors associated with willingness to continue working.Factors such as older age, living with a spouse, caring for younger children (up to 2 years old) at work, good mental health, and higher work engagement were significantly associated with teachers' higher willingness to continue working. Factors such as marriage, health and family problems, overtime work, issues with workplace childcare, and education policy, working time/day problems, human relations, and difficulties taking care of children were correlated with teachers' lack of willingness to continue working.The findings of this cross-sectional study suggest that welfare benefits and individual support systems could be key elements to encourage kindergarten teachers to continue working and could lead to their improved job satisfaction and mental health. Balanced work conditions and workers' high agreement with their workplace's overall childcare or educational policies may lead to lower turnover. Some programs - such as relationship counselling - could have a positive impact on teachers' mental health and job satisfaction.

Hemodynamic Signal Changes During Motor Imagery Task Performance Are Associated With the Degree of Motor Task Learning.

PURPOSE: This study aimed to investigate whether oxygenated hemoglobin (oxy-Hb) generated during a motor imagery (MI) task is associated with the motor learning level of the task. METHODS: We included 16 right-handed healthy participants who were trained to perform a ball rotation (BR) task. Hemodynamic brain activity was measured using near-infrared spectroscopy to monitor changes in oxy-Hb concentration during the BR MI task. The experimental protocol used a block design, and measurements were performed three times before and after the initial training of the BR task as well as after the final training. The BR count during training was also measured. Furthermore, subjective vividness of MI was evaluated three times after NIRS measurement using the Visual Analog Scale (VAS). RESULTS: The results showed that the number of BRs increased significantly with training (P < 0.001). VAS scores also improved with training (P < 0.001). Furthermore, oxy-Hb concentration and the region of interest (ROI) showed a main effect (P = 0.001). An interaction was confirmed (P < 0.001), and it was ascertained that the change in oxy-Hb concentrations due to training was different for each ROI. The most significant predictor of subjective MI vividness was supplementary motor area (SMA) oxy-Hb concentration (coefficient = 0.365). DISCUSSION: Hemodynamic brain activity during MI tasks may be correlated with task motor learning levels, since significant changes in oxy-Hb concentrations were observed following initial and final training in the SMA. In particular, hemodynamic brain activity in the SMA was suggested to reflect the MI vividness of participants.

A method for using video presentation to increase the vividness and activity of cortical regions during motor imagery tasks.

In recent years, mental practice (MP) using laterally inverted video of a subject's non-paralyzed upper limb to improve the vividness of presented motor imagery (MI) has been shown to be effective for improving the function of a paralyzed upper limb. However, no studies have yet assessed the activity of cortical regions engaged during MI task performance using inverse video presentations and neurophysiological indicators. This study sought to investigate changes in MI vividness and hemodynamic changes in the cerebral cortex during MI performance under the following three conditions in near-infrared spectroscopy: MI-only without inverse video presentation (MI-only), MI with action observation (AO) of an inverse video presentation of another person's hand (AO + MI (other hand)), and MI with AO of an inverse video presentation of a participant's own hand (AO + MI (own hand)). Participants included 66 healthy right-handed adults (41 men and 25 women; mean age: 26.3 ± 4.3 years). There were 23 patients in the MI-only group (mean age: 26.4 ± 4.1 years), 20 in the AO + MI (other hand) group (mean age: 25.9 ± 5.0 years), and 23 in the AO + MI (own hand) group (mean age: 26.9 ± 4.1 years). The MI task involved transferring 1 cm × 1 cm blocks from one plate to another, once per second, using chopsticks held in the non-dominant hand. Based on a visual analog scale (VAS), MI vividness was significantly higher in the AO + MI (own hand) group than in the MI-only group and the AO + MI (other hand) group. A main effect of condition was revealed in terms of MI vividness, as well as regions of interest (ROIs) in certain brain areas associated with motor processing. The data suggest that inverse video presentation of a person's own hand enhances the MI vividness and increases the activity of motor-related cortical areas during MI. This study was approved by the Institutional Ethics Committee of Nagasaki University Graduate School of Biomedical and Health Sciences (approval No. 18121303) on January 18, 2019.

A Study on the Effect of Mental Practice Using Motor Evoked Potential-Based Neurofeedback.

This study aimed to investigate whether the effect of mental practice (motor imagery training) can be enhanced by providing neurofeedback based on transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEP). Twenty-four healthy, right-handed subjects were enrolled in this study. The subjects were randomly allocated into two groups: a group that was given correct TMS feedback (Real-FB group) and a group that was given randomized false TMS feedback (Sham-FB group). The subjects imagined pushing the switch with just timing, when the target circle overlapped a cross at the center of the computer monitor. In the Real-FB group, feedback was provided to the subjects based on the MEP amplitude measured in the trial immediately preceding motor imagery. In contrast, the subjects of the Sham-FB group were provided with a feedback value that was independent of the MEP amplitude. TMS was applied when the target, moving from right to left, overlapped the cross at the center of the screen, and the MEP amplitude was measured. The MEP was recorded in the right first dorsal interosseous muscle. We evaluated the pre-mental practice and post-mental practice motor performance in both groups. As a result, a significant difference was observed in the percentage change of error values between the Real-FB group and the Sham-FB group. Furthermore, the MEP was significantly different between the groups in the 4th and 5th sets. Therefore, it was suggested that TMS-induced MEP-based neurofeedback might enhance the effect of mental practice.

Comparison of cerebral activation between motor execution and motor imagery of self-feeding activity.

Motor imagery is defined as an act wherein an individual contemplates a mental action of motor execution without apparent action. Mental practice executed by repetitive motor imagery can improve motor performance without simultaneous sensory input or overt output. We aimed to investigate cerebral hemodynamics during motor imagery and motor execution of a self-feeding activity using chopsticks. This study included 21 healthy right-handed volunteers. The self-feeding activity task comprised either motor imagery or motor execution of eating sliced cucumber pickles with chopsticks to examine eight regions of interest: pre-supplementary motor area, supplementary motor area, bilateral prefrontal cortex, premotor area, and sensorimotor cortex. The mean oxyhemoglobin levels were detected using near-infrared spectroscopy to reflect cerebral activation. The mean oxyhemoglobin levels during motor execution were significantly higher in the left sensorimotor cortex than in the supplementary motor area and the left premotor area. Moreover, significantly higher oxyhemoglobin levels were detected in the supplementary motor area and the left premotor area during motor imagery, compared to motor execution. Supplementary motor area and premotor area had important roles in the motor imagery of self-feeding activity. Moreover, the activation levels of the supplementary motor area and the premotor area during motor execution and motor imagery are likely affected by intentional cognitive processes. Levels of cerebral activation differed in some areas during motor execution and motor imagery of a self-feeding activity. This study was approved by the Ethical Review Committee of Nagasaki University (approval No. 18110801) on December 10, 2018.

Cerebral haemodynamics during motor imagery of self-feeding with chopsticks: differences between dominant and non-dominant hand.

Purpose: Motor imagery is defined as a dynamic state during which a subject mentally simulates a given action without overt movements. Our aim was to use near-infrared spectroscopy to investigate differences in cerebral haemodynamics during motor imagery of self-feeding with chopsticks using the dominant or non-dominant hand.Materials and methods: Twenty healthy right-handed people participated in this study. The motor imagery task involved eating sliced cucumber pickles using chopsticks with the dominant (right) or non-dominant (left) hand. Activation of regions of interest (pre-supplementary motor area, supplementary motor area, pre-motor area, pre-frontal cortex, and sensorimotor cortex was assessed.Results: Motor imagery vividness of the dominant hand tended to be significantly higher than that of the non-dominant hand. The time of peak oxygenated haemoglobin was significantly earlier in the right pre-frontal cortex than in the supplementary motor area and left pre-motor area. Haemodynamic correlations were detected in more regions of interest during dominant-hand motor imagery than during non-dominant-hand motor imagery.Conclusions: Haemodynamics might be affected by differences in motor imagery vividness caused by variations in motor manipulation.