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Charles A. J. Macaulay Pro Stergiou Darren Stefanyshyn Luciano Tomaghelli 《Journal of sports sciences》2017,35(23):2350-2356
Lacrosse requires the coordinated performance of many complex skills. One of these skills is shooting on the opponents’ net using one of three techniques: overhand, sidearm or underhand. The purpose of this study was to (i) determine which technique generated the highest ball velocity and greatest shot accuracy and (ii) identify kinematic and kinetic variables that contribute to a high velocity and high accuracy shot. Twelve elite male lacrosse players participated in this study. Kinematic data were sampled at 250 Hz, while two-dimensional force plates collected ground reaction force data (1000 Hz). Statistical analysis showed significantly greater ball velocity for the sidearm technique than overhand (P < 0.001) and underhand (P < 0.001) techniques. No statistical difference was found for shot accuracy (P > 0.05). Kinematic and kinetic variables were not significantly correlated to shot accuracy or velocity across all shot types; however, when analysed independently, the lead foot horizontal impulse showed a negative correlation with underhand ball velocity (P = 0.042). This study identifies the technique with the highest ball velocity, defines kinematic and kinetic predictors related to ball velocity and provides information to coaches and athletes concerned with improving lacrosse shot performance. 相似文献
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目的:探讨有氧运动对大鼠心血管和胸主动脉平滑肌的功能重塑作用及可能的钾通道机制。方法:选用2月龄雄性Wistar大鼠20只,随机分为安静对照组和有氧运动组,进行8周跑台运动。8周后,选取部分动物(各组5只)进行股动静脉插管,插管留置体内并从颈部皮肤切口穿出固定。术后恢复1 d后,于在体、清醒状态下测定基础血压、心率,并经股静脉注射Ang II和非特异性钾通道阻断剂TEA,观察其心血管反应。另10只大鼠,开胸取胸主动脉,去内皮,并制备血管环,进行离体血管收缩特性检测。结果:1)有氧运动后大鼠的安静心率显著下降;平均动脉压有下降趋势,但与安静对照组比无显著性差异;2)静脉注射Ang II引起的升压反应幅度减小;3)静脉注射非特异性钾通道阻断剂TEA可诱发升压反应,且运动组较安静对照组显著;4)两组去内皮胸主动脉血管环对于Ang II(10-9~10-4M)均有浓度依赖性收缩,但有氧运动组的最大张力显著低于安静对照组;5)TEA(5×10-3M)可诱发大鼠血管张力增加,运动组升高幅度显著大于安静组。结论:有氧运动可诱导大鼠心血管和胸主动脉平滑肌出现功能重塑,其中钾通道活性的增强可能是重要机制之一。 相似文献
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将SD大鼠随机分成训练组和对照组，参照Bedford大鼠耐力训练模型对训练组进行电动跑台训练，16周后将SD大鼠断头处死，将胸主动脉取出，使用计算机图像采集及分析系统测量血管环的张开角、壁厚、内径并计算壁厚／内径。结果表明：在零应力状态下测定张开角发现，训练组的张开角比对照组减小，而血管的壁厚却无明显差异；在血管的管径方面，训练组较对照组明显增大。表明耐力运动可以造成SD大鼠胸主动脉零应力状态及几何形态学的重建。 相似文献
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我国优秀艺术体操运动员脊柱形态的调查研究 总被引：1，自引：0，他引：1
对我国现阶段不同省份不同年龄的46名优秀艺术体操运动员的胸椎下部至骶骨上部进行了X线摄片检查，对脊柱曲度，顺列、椎间隙和椎体形态的改变进行了观察与分析。结合临床检查，发现该项目运动员的脊柱存在着严重的问题，成为影响运动员正常训练和提高成绩的主要因素之一。 相似文献
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目的：探索床旁快捷教学法在胸外科见习中的应用。方法：对到胸外科见习的临床医学本科生进行床旁快捷教学,评估教学效果。结果：胸外科见习中运用床旁快捷教学法,教学效果良好。结论：胸外科见习中运用床旁快捷教学法有助于迅速调动学生的积极性,激发学生的兴趣,培养语言表达能力和思考分析能力,提高教学效率,值得推广使用。 相似文献
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运动训练对大鼠主动脉一氧化氮合酶及细胞凋亡的影响 总被引：2，自引：4，他引：2
目的:探讨不同强度训练对大鼠主动脉一氧化氮合酶(NOS)及细胞凋亡的影响。方法:采用跑台训练方式,建立大鼠有氧运动和疲劳运动模型,运用免疫组织化学SABC法研究不同运动强度对大鼠主动脉神经型一氧化氮合酶(neuronal nitric oxide synthase,nNOS)、诱导型一氧化氮合酶(in-duced nitric oxide synthase,iNOS)、内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)和细胞凋亡蛋白(Bcl-2/Bax)表达的影响。结果:有氧训练组与对照组比较,主动脉NOS 3个亚型及Bcl-2,Bax表达差异显著(P<0.05);疲劳训练组与对照组和有氧训练组比较,主动脉iNOS、eNOS及Bcl-2,Bax表达差异显著(P<0.05),nNOS虽有增加但差异不显著。结论:运动可引起大鼠主动脉NOS 3个亚型及Bcl-2,Bax表达变化,且与运动强度关系密切。有氧训练可使主动脉NOS适度表达且抑制细胞凋亡,疲劳训练会导致大鼠主动脉iNOS过量表达,细胞发生凋亡现象。因此认为,运动训练引起NOS亚型表达变化与运动诱导的主动脉细胞凋亡关系密切。 相似文献
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Jess Rasmussen Birgitte Hanel Kari Saunamaki Niels H. Secher 《Journal of sports sciences》2013,31(6):525-531
Abstract Pulmonary diffusing capacity (Dlco), together with spirometric variables, arterial oxygen tension (paO2) and cardiac output were determined before and at intervals after maximal arm cranking, treadmill running and erogmeter rowing. Independent of the type of exercise, Dlco increased immediately post‐exercise from a median 13.6 (range 7.3–16.3) to 15.1 (9.3–19.6) mmol min‐1 kPa‐1 (P <0.01). However, it decreased to 11.6 (6.9–15.5) mmol min‐1 kPa‐1 (P <0.01) after 24 h with cardiac output and paO2 at resting values, and Dlco normalized after 20 h. Thoracic electrical impedance at 2.5 and 100 kHz increased slightly post‐exercise, indicating a decrease in thoracic fluid balance, and there were no echocardiographic signs of left ventricular failure at the time of the decrease in Dlco. Also, active muscle (limb) circumference and volume, and an increase in haematocrit from 43.8 (38.0–47.0) to 47.1 (42.7–49.8) (P <0.01), had normalized at the time of the decrease in Dlco. Vital capacity, forced vital capacity, forced expiratory volume in 1 s, peak and peak mid‐expiratory flows did not change. However, total lung capacity increased from 6.8 (5.0–7.6) to 7.0 (5.1–7.8) litres (P <0.05) immediately after exercise and remained elevated at 6.9 (5.1–8.7) litres (P <0.05) when a decrease in Dlco was noted. The results demonstrate that independent of the type of maximal exercise, an approximate 15% reduction in Dlco takes place 2–3 h post‐exercise, which normalizes during the following day of recovery. 相似文献
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目的：探讨肿瘤全椎体切除植骨椎弓根钉内固定手术配合体会。方法：加强术前访视、术中护理配合,积极采取针对性的护理措施,预防术中并发症的发生。结果手术配合默契,术后病情好转,出院3个月随访,患者功能恢复良好,未出现并发症和不良反应。结论：术前完善的准备、术中紧密的医护配合及术后并发症的观察是手术成功的重要保证。 相似文献
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为探讨运动训练对大血管的影响，对长期游泳训练的大鼠主动脉中膜作了透射电镜及光镜的配合观察。结果发现：游泳训练后的大鼠主动脉中膜平滑肌细胞线粒体、粗面内质网、微饮小泡等超微结构产生了形态学上的变化。中膜弹力纤维增多有利于大动脉的弹性贮器功能。为进一步研究运动训练对大血管的影响提供了形态学上的依据。 相似文献