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1.
Ayako Higashihara Yasuharu Nagano Takashi Ono Toru Fukubayashi 《European Journal of Sport Science》2016,16(1):36-41
The purpose of this study was to investigate the time series relationships between the peak musculotendon length and electromyography (EMG) activation during overground sprinting to clarify the risk of muscle strain injury incidence in each hamstring muscle. Full-body kinematics and EMG of the right biceps femoris long head (BFlh) and semitendinosus (ST) muscles were recorded in 13 male sprinters during overground sprinting at maximum effort. The hamstring musculotendon lengths during sprinting were computed using a three-dimensional musculoskeletal model. The time of the peak musculotendon length, in terms of the percentage of the running gait cycle, was measured and compared with that of the peak EMG activity. The maximum length of the hamstring muscles was noted during the late swing phase of sprinting. The peak musculotendon length was synchronous with the peak EMG activation in the BFlh muscle, while the time of peak musculotendon length in the ST muscle occurred significantly later than the peak level of EMG activation (p < 0.05). These results suggest that the BFlh muscle is exposed to an instantaneous high tensile force during the late swing phase of sprinting, indicating a higher risk for muscle strain injury. 相似文献
2.
Ayako Higashihara Yasuharu Nagano Kazumasa Takahashi Toru Fukubayashi 《Journal of sports sciences》2015,33(13):1366-1375
This study aimed to investigate the effects of forward trunk lean on hamstring muscle kinematics during sprinting. Eight male sprinters performed maximal-effort sprints in two trunk positions: forward lean and upright. A three-dimensional musculoskeletal model was used to compute the musculotendon lengths and velocity of the biceps femoris long head, semitendinosus, and semimembranosus muscles during the sprinting gait cycle. The musculotendon lengths of all the three hamstring muscles at foot strike and toe-off were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. In addition, a positive peak musculotendon lengthening velocity was observed in the biceps femoris long head and semimembranosus muscles during the late stance phase, and musculotendon lengths at that instant were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. The present study provides significant evidence that a potential for hamstring muscle strain injury involving forward trunk lean sprinting would exist during the stance phase. The results also indicate that the biceps femoris long head and semimembranosus muscles are stretched during forward trunk lean sprinting while contracting eccentrically in the late stance phase; thus, the elongation load on these muscles could be increased. 相似文献
3.
Miyamoto N Wakahara T Sugisaki N Murata K Kanehisa H Fukunaga T Kawakami Y 《Journal of sports sciences》2010,28(14):1535-1542
The aim of the present study was to examine elbow joint extension power-load characteristics with and without a countermovement. Eight male participants performed maximal elbow extensions with and without a countermovement against different loads (0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0 kg). Electromyographic activity of the lateral and long heads of the triceps brachii and the biceps brachii muscles was recorded. The average joint power in the concentric phase was significantly enhanced in the countermovement condition at all loads except for 0 kg. The optimal load for the maximal joint power was greater in the countermovement (7.5 kg) than in the no countermovement condition (5.0 kg). Electromyographic activity was unchanged over the intensities and conditions. Our results suggest that the optimal load for the maximal joint power depends on the type of action (i.e. with or without a counter-movement), and that the enhanced joint power in the countermovement condition is due primarily to the storage and utilization of elastic energy. 相似文献
4.
Ayako Higashihara Yasuharu Nagano Takashi Ono Toru Fukubayashi 《Journal of sports sciences》2018,36(12):1313-1318
This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances. 相似文献
5.
OBJECTIVE: This article explores characteristics of Munchausen Syndrome by Proxy (MSBP) in Japan, a country which provides an egalitarian, low cost, and easy-access health care system. METHODS: We sent a questionnaire survey to 11 leading doctors in the child abuse field in Japan, each located in different hospital-based sites. Child abuse doctors answered questions regarding the characteristics of MSBP cases for whom they had helped care. RESULTS: Twenty-one MSBP cases (20 families) were reported. Characteristics of the victims included: no differences based on sex, 4.6 years of age on average when MSBP was confirmed, and an average of 1.9 years duration of MSBP abuse. Biological mothers were at least one of the perpetrators in 95% of cases. Among the 12 cases (57%) who remained with their families, 2 victims died. Only 5% of perpetrators had a medical background or relatives who engaged in healthcare work. CONCLUSION: There are similar features of MSBP cases between Japan and other English-speaking countries, such as the UK or the US. However, perpetrators of MSBP in Japan did not have a medical background. Easier access to hospital resources in Japan may give greater opportunities for perpetrators to obtain medical knowledge from doctors or nurses. PRACTICE IMPLICATIONS: The findings suggest that perpetrators of MSBP should not be assumed to possess a medical background in a country which provides universal medical care such as Japan. A contributory factor of MSBP may be the high frequency of medical consultations and equal level of accessibility of medical resources for Japanese citizens. Social welfare services that need to decide on custody for MSBP victims should recognize the relatively high risk of life-threatening danger in their family of origin. Further collaboration between hospital staff including pediatricians, nurses, medical social workers and staff at the social welfare services is needed to protect children from MSBP. 相似文献
6.
This paper describes a successful cross-training and reference librarian exchange experience involving two librarians at UCLA, one based at the Louise M. Darling Biomedical Library and the other based at the College Library, which primarily serves undergraduates. The experience has increased the reference skills and expertise of both librarians by introducing them to new sets of reference tools and databases, and has broadened their network of colleagues within the UCLA Library system. The participating libraries have also benefited from the exchange, and the program is expanding to include other UCLA libraries. 相似文献
7.
Yasuharu Nagano Shogo Sasaki Ayako Higashihara Hiroshi Ichikawa 《Sports biomechanics / International Society of Biomechanics in Sports》2020,19(3):342-352
AbstractThis study aimed to elucidate the movements requiring greater trunk accelerations and its frequencies during badminton games, and compare the acceleration components among such movements. Trunk acceleration was measured using a triaxial accelerometer during badminton games. The moments that generated >4 G resultant acceleration were extracted, and movements consistent with the extracted moments were identified. We calculated the extracted movement ratio and frequency and compared the resultant, mediolateral, vertical and anteroposterior accelerations between the top five extracted movements. There were 1,342 movements that generated >4 G [mean, 7.72 (95% confidence interval, 7.31–8.14) cases/min]. The top five movements were lunging during underhand strokes with the dominant hand side leg, landing after overhand strokes on the dominant and non-dominant hand side leg, and cutting from a split step using the dominant and non-dominant hand side leg. Landing on the dominant hand side leg had a greater resultant acceleration than the other movements and had the greatest impact during the badminton game. Lunging during underhand strokes on the dominant hand side leg had greater mediolateral acceleration than the other movements. These results reflected the properties of badminton. 相似文献
8.
Differences between Japanese Infants and Caucasian American Infants in Behavioral and Cortisol Response to Inoculation 总被引：2，自引：0，他引：2
The behavioral and cortisol responses of Japanese infants and Caucasian American infants, 4 months of age, were observed during and following routine inoculation. The Caucasian American group showed a more intense initial affective response and a longer latency to quiet than the Japanese group; the Japanese group showed a greater cortisol response. A 4-group taxonomy was created based on high or low behavioral and cortisol response: high behavior–high cortisol, low behavior–low cortisol, high behavior–low cortisol, and low behavior–high cortisol. There were significant differences between the 2 groups of infants using this taxonomy: Infants in the Caucasian American group were more likely to fall in the high behavior–low cortisol group, while infants in the Japanese group were more likely to fall in the low behavior–high cortisol group. 相似文献
9.
Inagaki Ayako 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》2002,48(3-4):279-280
International Review of Education - 相似文献
10.
Yasuharu Nagano Ayako Higashihara Kazumasa Takahashi Toru Fukubayashi 《Journal of sports sciences》2013,31(18):1722-1728
AbstractWe aimed to demonstrate the changes over time in the lengths and forces of the muscles crossing the hip joint during overground sprinting and investigate the relationships between muscle lengths and muscle–tendon unit forces – particularly peak biceps femoris force. We obtained three-dimensional kinematics during 1 running cycle from 8 healthy sprinters sprinting at maximum speed. Muscle lengths and muscle–tendon unit forces were calculated for the iliacus, rectus femoris, gluteus maximus, and biceps femoris muscles of the target leg as well as the contralateral iliacus and rectus femoris. Our results showed that during sprinting, the muscles crossing the hip joint demonstrate a stretch-shortening cycle and 1 or 2 peak forces. The timing of peak biceps femoris force, expressed as a percentage of the running cycle (mean [SD], 80.5 [2.9]%), was synchronous with those of the maximum biceps femoris length (82.8 [1.9]%) and peak forces of the gluteus maximus (83.8 [9.1]%), iliacus (81.1 [5.2]%), and contralateral iliacus (78.5 [5.8]%) and also that of the peak pelvic anterior tilt. The force of the biceps femoris appeared to be influenced by the actions of the muscles crossing the hip joint as well as by the pelvic anterior tilt. 相似文献