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Auroral brightening is one of the most common phenomena that occur during substorm onset and is usually recognized as a projection of the substorm‐associated magnetospheric plasma dynamics to the ionosphere. However, electromagnetic fields and plasma features associated with the substorm brightening arc have not been well understood. In this study, we present a comprehensive observation of the source plasma and field variations of a substorm brightening aurora in the inner magnetosphere. We performed a unique conjugate observation of a substorm brightening auroral arc observed by a ground‐based camera and by the Arase satellite in the magnetospheric source region at L ∼ 6. The event was observed at Tromsø (69.6°N, 19.2°E), Norway, on 12 October 2017. The brightening arc indicates east‐west structures with longitudinal scales of ∼0.5°–2.0°. Field‐aligned bi‐directional electrons with an energy range between 66 and 1,800 eV were detected by the satellite, simultaneously with the appearance of the brightening arc in the camera. These electrons were probably supplied from the auroral brightening region in the ionosphere, indicating that the satellite was on the same field line of the brightening aurora. The magnetic and electric field data show characteristic fluctuations and earthward Poynting flux around the time that the satellite crossed the aurora. Anti‐phase oscillations between the thermal pressure and the magnetic pressure are also reported. Based on these observations, we suggest the possibility that a ballooning instability occurred in the source region of the substorm brightening arc in the inner magnetosphere at L ∼ 6. Plain Language Summary: A frequently occurring source of variations in the magnetosphere is the substorm, a process that causes energy dissipation into the atmosphere. Substorm is presented as the development of aurorae at high latitudes in the ionosphere. The study of substorm processes helps in understanding the near‐Earth space environment and the space weather. Along Earth's magnetic field lines, the aurora at a latitude of ∼65°N can be traced to ∼4–7 Earth radii away from the Earth at the equatorial plane in space. Using a ground‐based auroral camera, we can construct the correspondence between auroral motion and field and plasma variation at the satellite. This study reports such a unique event of substorm brightening arc observed at Tromsø, Norway, on 12 October 2017. Satellite observed bi‐directional electrons prove the connection between aurora break‐up at ∼100 km altitude and its source region in the magnetosphere at ∼30,000 km away from Earth. Based on the magnetic wave spectrograms, auroral bead‐like structures and other observational results, we suggest the possibility that a ballooning plasma instability occurred in the source region of the substorm brightening arc in the inner magnetosphere. Key Points: Observation of plasma and field features in the source region of a sudden brightening auroral arc during a minor substorm onset at L ∼ 6Energization of particles, field‐aligned electrons, and electromagnetic field fluctuations were observed during the arc crossing by AraseSeveral observational facts indicate the possibility of ballooning instability occurring at this substorm onset [ABSTRACT FROM AUTHOR]

Introduction: Cold exposures impair neuromuscular function.1 Tensiomyography (TMG) non-invasively assesses muscle contractile properties with electrical stimulation.2 Until present, there are no reports to clarify icing effects on muscle contractile properties with TMG. Objective: To investigate the effects of icing on muscle temperature and contractile properties. Methods: Eight healthy males (age: 22.9 ± 2.2 years) participated in this study. Each participant completed two conditions (icing and control) each for 15 minutes on separate days in a random order. Icing was applied on the right gastrocnemius muscles. Muscle temperature was measured at gastrocnemius lateralis. Muscle contractile properties of the gastrocnemius medialis were measured using Tensiomyography (TMG--100). The stimulation intensity was increased gradually to 20 mA, reaching a plateau in the twitch response curve. TMG parameters, including maximal radial displacement (Dm), delay time (Td), contraction time (Tc), and velocity of contraction (Vc), were then measured from the maximal twitch response. Two-way repeated-measures ANOVA was performed, and the Bonferroni test was used for post-hoc comparisons. Results: In the icing condition, muscle temperature were significantly decreased (Pre: 34.2 ± 0.9 °C; Post: 28.6 ± 2.7 °C, p < 0.001). Neuromuscular properties were shown with Td (Pre: 20.2 ± 1.1 ms; Post: 23.9 ± 1.4 ms, p < 0.001), Tc (Pre: 20.9 ± 2.1 ms; Post: 23.2 ± 2.6 ms, p = 0.021) and Vc (Pre: 0.087 ± 0.024 mm/ms; Post: 0.076 ± 0.021 mm/ms, p < 0.001) were significantly impaired after icing. However, no significant changes with Dm in icing condition (p = 0.206) and muscle temperature and TMG parameters in control condition (p = 0.092-0.994). Conclusion: Icing temporally impairs muscle contractile properties, but the maximal radial displacement remains unchanged. The present results suggest that icing may negatively affect neuromuscular properties without altering mechanical properties with the muscle contraction. [ABSTRACT FROM AUTHOR]

Introduction: Repetitive baseball pitching causes valgus stress on elbow joints and consequently increases ulnar collateral ligament (UCL) injury risk.1 The medial elbow joint space was found to increase after 60 pitches in a previous study.2,3 However, the pitching task in the previous study was performed on "straight" pitches only in a controlled setting. Objectives: To investigate the repetitive pitching effects in a baseball game on the medial joint space at elbow joint. Design: A cross-sectional study Methods: Twenty-six young male collegiate baseball pitchers were enrolled. The medial elbow joint space was measured using ultrasonography in the following conditions: resting with forearm on bed (unloaded), valgus load with forearm weight (loaded), and valgus load with forearm weight and maximal grip (loaded-contracted). The medial elbow joint space was measured before and after pitching in a game. Subgroup analysis was conducted considering the throwing frequency (≥ 60 pitches and < 60 pitches). The minimum detectable change (MDC) was also calculated. Two-way repeated-measures analysis of variance was used to assess the effects of the game and condition on the medial elbow joint space. Results: In the analysis of all participants, the medial elbow joint space significantly increased (0.14 mm) after pitching in the loaded condition (p = 0.01). In the subgroup analysis, the medial elbow joint space in the ≥ 60 pitches significantly increased (0.13 mm) after pitching in the loaded contraction (p = 0.02). However, none of these results exceeded the MDC (0.28 mm). There were no significant changes in the < 60 pitches. Conclusions: Repetitive pitching with various types of throwing in an actual game was indicated to decrease elbow valgus stability. However, the effect may be considered small due to less than the MDC. [ABSTRACT FROM AUTHOR]

Introduction: Middle-aged women are influenced by mood symptoms such as anxiety which may be associated with autonomic modulation.1 Stretching improves mood symptoms and increases parasympathetic activity. However, there are no reports that examine these indicators simultaneously.2,3 Objective: To investigate the acute effects of stretching on mood symptoms and autonomic modulation in middle-aged women. Methods: Twenty-five middle-aged women (age: 51.8 ± 4.4 years) enrolled in this study. Each participant completed two conditions (static stretching and control) for 25 minutes each on separate days in a random order. Static stretching was conducted with a whole-body program. The mood symptoms were measured using the State Trait Anxiety Inventory (STAI) questionnaire. Total score, subscales of anxiety-present and anxiety-absent were calculated pre- and post-intervention. Autonomic modulation was measured by heart rate variability (HRV). The HRV indices which assess parasympathetic activity were calculated with the root mean square of successive differences (RMSSD) and high-frequency power (HF) pre- and post-intervention and again 30 minutes later (PRE, POST-0, POST-30). The RMSSD and HF were transformed using the natural logarithm. Two-way repeated-measures analysis of variance was performed, and the Bonferroni test was used for posthoc comparisons. Results: In the stretching condition, mood symptoms, especially state anxiety indicated with STAI-total (PRE: 34.2 ± 7.7; POST-0: 29.6 ± 6.7, p = < 0.001) and positive mood state determined with STAI-anxiety absent (PRE: 22.5 ± 6.9; POST0: 19.1 ± 6.3, p = < 0.001) were significantly improved after stretching. However, there were no significant changes with RMSSD and HF with either POST-0 or POST-30 in both stretching and control condition (p = 0.068-0.808). Conclusion: Stretching immediately improved mood symptoms in middle-aged women. However, autonomic modulations were unchanged after stretching. Therefore, stretching is an effective intervention for mood symptoms in middle-aged women. [ABSTRACT FROM AUTHOR]