Mental Health and Physical Activity among Children and Adolescents during the COVID-19 Pandemic.

Coronavirus disease 2019 (COVID-19) is causing disruptions in the global social system. Japanese children and adolescents have had their schools closed, government-mandated activity restrictions imposed, and interactions outside the home reduced. These restrictions can have a considerable psychological impact on children and adolescents. This review aims to describe the impacts of COVID-19 pandemic on physical activity and psychological status of this population. The review was conducted by searching PubMed for information on the impact of COVID-19-related activity restrictions on children and adolescents. The search identified 11 articles, three of which contained data on anxiety and psychological problems due to physical inactivity. Next, a PubMed search was conducted about physical activity and psychological status in children and adolescents under psychological stress. The search identified 368 articles, 28 of which were included in the review. For children, data that revealed a correlation between physical activity and psychological health and sedentary time leading to mood disorders were included. For adolescents, there were nine studies that reported a correlation between physical activity and psychological health and four studies that reported no correlation between physical activity and psychological health. Of the studies that reported a correlation, seven reported that physical activity improves psychological health. The impact of psychologically stressful situations such as COVID-19 on children and adolescents has been experienced worldwide. Physical activity has been correlated with psychological health, and it may improve psychological status; physical activity should be recommended to better support the psychological health of children and adolescents under the influence of COVID-19.

Relationship between Muscle Fiber Conduction Velocity and the Force-time Curve during Muscle Twitches.

[Purpose] The aim of this study was to clarify the relationship between the muscle fiber conduction velocity (MFCV) obtained during muscle twitches from evoked potentials and the dynamic characteristics of muscular tension (muscle dynamic characteristics) by manipulating deep temperature. [Subjects] Subjects were 10 healthy adult men. Their mean age was 23.0 ± 3.9 years. [Methods] Measurement items were MFCV of the right tibialis anterior muscle and the force-time curve of right ankle dorsiflexion (muscle twitch). Measurements were made under conditions of ordinary (room) temperature, hot and cold. The rate of change in maximum torque was calculated from the force-time curve. [Results] In all subjects, MFCV increased significantly with heating and decreased significantly with cooling. A strong correlation was seen between MFCV and deep temperature. A strong correlation was also seen between MFCV and the rate of change in maximum torque. Stronger correlations were seen in the present results than in previous studies that conducted investigations using voluntary contractions. [Conclusion] The present results were not affected by psychological or other such factors, and are valuable as data with high physiological reliability. In conclusion, this study was able to clarify the relationship between MFCV from evoked potentials and muscle dynamic characteristics.

The effect of combined risk factors on breast cancer-related lymphedema: a study using decision trees.

BACKGROUND: The effect of combined risk factors on breast cancer-related lymphedema (BCRL) development has not yet been investigated. This study aimed to determine the combination of risk factors associated with BCRL development in patients who underwent breast cancer resection, including axillary lymph node dissection (ALND). METHODS: The participants included 129 women who were diagnosed with early-stage breast cancer and underwent breast cancer resection in this retrospective observational study. We performed a decision tree analysis to detect the combination of risk factors associated with BCRL development using age, body mass index (BMI), surgical side, mastectomy, the extent of ALND, and adjuvant therapy (chemotherapy, hormone therapy, and radiation therapy). RESULTS: Of the 129 participants, 11 (8.5%) developed BCRL. Postoperative chemotherapy was the optimal variable selected to classify patients who developed BCRL and those who did not. In participants with postoperative chemotherapy, the extent of ALND was selected as the second layer of the decision tree. When ALND was at level 3, BMI was selected as the third layer. We found that BCRL incidence was 44.4% in individuals with a BMI of 23.0 or higher. CONCLUSIONS: The combination of postoperative chemotherapy, level 3 ALND, and BMI of 23.0 or higher may further increase the risk of developing BCRL. The decision tree model will enable the identification of patients with a high risk of developing BCRL, and thus, preventive intervention, careful monitoring, and early treatment will be possible.