排序方式： 共有47条查询结果，搜索用时 15 毫秒
31.
Fiona Wilson John Gormley Conor Gissane Ciaran Simms 《Journal of sports sciences》2013,31(14):1481-1489
Abstract Lumbar spine injury is common in rowers and examination of spinal kinematics may improve the understanding of this injury's prevalence. This study aimed to examine the range of frontal plane angular displacement (AD) in the lumbar spine at L3 during ergometer rowing and to investigate the effect of exhaustion on lumbar kinematics. Twelve elite male rowers completed an incremental test on a Concept 2 ergometer. Lumbar AD at L3 was measured continually throughout the rowing trial using a Spectrotilt Inclinometer and blood lactate was sampled at 3-minute intervals. AD of between 4.7° and 8.8° was recorded at L3. There was a significant increase in AD between the first and last stage of the test (mean increase = 4.1 ± 1.94°, 95% Confidence Interval [CI], 2.9 to 5.3°, t = 7.36, P = 0.000014). Incremental rise in AD was associated with an incremental rise in blood lactate but regression confirmed that only stroke rate was a significant predictor for increasing angle. Thus there is a statistically significant increase in frontal plane AD at L3 over the course of an incremental exercise test although it cannot be confirmed if this is as a result of exhaustion. The values of AD confirm that there is motion in the frontal plane in ergometer rowing. 相似文献
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Benjamin Lee 《Journal of sports sciences》2017,35(18):1768-1780
Ballistic limb motion is enabled by proximal “core” stiffness. However, controversy exists regarding the best method of training this characteristic. This study sought to determine the most effective core training method to enhance distal limb athleticism. A total of 12 participants (24 ± 3 years, 1.8 ± 0.05 m, 76.8 ± 9.7 kg) consisting of Muay Thai athletes performed a core training protocol (Isometric vs. Dynamic, with Control) for 6 weeks, using a repeated measures design to assess performance (peak strike velocity, peak impact force, muscular activation) in various strikes. Isometric training increased impact force in Jab (554.4 ± 70.1 N), Cross (1895.2 ± 203.1 N), Combo (616.8 ± 54.9 N), and Knee (1240.0 ± 89.1 N) trials (P < 0.05). Dynamic training increased strike velocity in Jab (1.3 ± 0.2 m · s?1), Cross (5.5 ± 0.9 m · s?1), Combo (0.7 ± 0.1, 2.8 ± 0.3 m · s?1), and Knee (3.2 ± 0.3 m · s?1) trials (P < 0.05). Isometric training increased Combo impact force 935.1 ± 100.3 N greater than Dynamic and 931.6 ± 108.5 N more than Control (P < 0.05). Dynamic training increased Jab strike velocity 1.3 ± 0.1 m · s?1 greater than Isometric and 0.8 ± 0.1 m · s?1 more than Control (P < 0.05). It appears that both static and dynamic approaches to core training are needed to enhance both velocity and force in distal limbs. 相似文献
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目的:通过对脊柱形态的测量,找出长期冲击应力对蹦床运动员脊柱的影响。方法:通过Spinal Mouse脊柱测量仪,对8名高水平蹦床运动员和20名正常大学生进行脊柱测量,并进行比较,找出两者的差异之处。结果:运动员和大学生脊柱在静态和动态情况下角度都存在不同程度的差异。结论:通过对测得的脊柱数据进行比较分析,长期的冲击应力使得蹦床运动员直立时腰椎的生理弯曲变小,骨盆前倾减小,但是对胸椎的生理弯曲影响不大。在脊柱动态活动时,蹦床运动员胸椎的活动度变小,腰椎的活动度没有变化,骨盆活动度变大,脊柱总活动度变大。 相似文献
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Alejandro Martínez-Cava Ricardo Morán-Navarro Luis Sánchez-Medina Juan José González-Badillo 《Journal of sports sciences》2019,37(10):1088-1096
This study aimed to compare the load-velocity and load-power relationships of three common variations of the squat exercise. 52 strength-trained males performed a progressive loading test up to the one-repetition maximum (1RM) in the full (F-SQ), parallel (P-SQ) and half (H-SQ) squat, conducted in random order on separate days. Bar velocity and vertical force were measured by means of a linear velocity transducer time-synchronized with a force platform. The relative load that maximized power output (Pmax) was analyzed using three outcome measures: mean concentric (MP), mean propulsive (MPP) and peak power (PP), while also including or excluding body mass in force calculations. 1RM was significantly different between exercises. Load-velocity and load-power relationships were significantly different between the F-SQ, P-SQ and H-SQ variations. Close relationships (R2 = 0.92–0.96) between load (%1RM) and bar velocity were found and they were specific for each squat variation, with faster velocities the greater the squat depth. Unlike the F-SQ and P-SQ, no sticking region was observed for the H-SQ when lifting high loads. The Pmax corresponded to a broad load range and was greatly influenced by how force output is calculated (including or excluding body mass) as well as the exact outcome variable used (MP, MPP, PP). 相似文献
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分析优秀艺术体操运动员脊柱腰段损伤现状，探讨损伤的规律。结果表明：97．5％的运动员患有腰部损伤，10096的运动员表示有过不同程度的腰部疼痛；发病率前5位的损伤部位是腰椎间盘突出、腰椎峡部裂、棘突偏歪、腰椎错位和腰肌劳损；损伤多发生在重要赛事前准备期。腰部损伤规律主要表现在技术结构的特殊性、脊柱腰段过度的伸展性、技术水平的不均衡性、个人集体项目的差异性和形态与机能交化外显的不一致性。 相似文献
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新闻出版工作者的历史使命 总被引：1，自引：0，他引：1
张铁莉 《大连教育学院学报》2002,18(3):80-81
江泽民“三个代表”重要思想对新闻出版工作有着重要的指导意义。新闻出版工作者应在全面贯彻“三个代表”精神的过程中 ,努力把握“代表中国先进文化的前进方向”的内涵和精神实质 ,做中国先进文化的建设者和传播者 相似文献
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赵梦园 《体育科技文献通报》2020,(2):157-158
下背痛是常见的、给社会造成严重经济负担的肌肉骨骼疾病。从生物力学角度出发,浅析腰椎损伤常见原因,下背痛患者正常活动、妊娠下背痛、下背痛患者治疗中的生物力学。 相似文献
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Adrien Cerrito Peter Milburn Clair Alston-Knox Kerrie Evans 《Journal of sports sciences》2019,37(13):1551-1559
The aim of this study was to compare cervical spine kinematics in rugby union front row players during machine-based and “live” scrummaging. Cervical spine kinematics was measured via electromagnetic tracking of sensors attached to the head and thorax. Joint angles were extracted from each trial at two time points (“bind” prior to engagement and instant of impact) for comparison between scrummaging conditions. The effect of scrummaging condition on kinematics was evaluated using a mixed effects model and estimations were based on a Bayesian framework. With differences ranging from 38° to 50°, the results show that the cervical spine is consistently more flexed when scrummaging against opponents than against a scrum machine. In contrast, there are little differences in the excursion of lateral-flexion (range 5–8°) and axial rotation (7°) between the two conditions. The findings from this study provide clear information on motion patterns in different scrum formations, and suggest that the current design of scrum machines may not promote the same pattern of movement that occurs in live scrums. The results highlight that findings from previous studies that have investigated kinematics during machine-based scrummaging may not be generalisable to a competitive scrummaging context. 相似文献
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摘要：目的：探索非特异性腰痛（NLBP）患者中腰椎稳定性与躯干肌群形态、张力及力量等各方面特性的关系以及相关因素对这种关系的影响。方法：招募青年男性参与者，包括不同腰椎稳定性NLBP亚组（LSI组10人，Non-LSI组9人）以及正常对照组（10人）。测试采集脊柱肌群CSA、张力等数据以及最大等长屈伸力量。通过多元方差分析（MANOVA）比较各指标在参与者组别以及各种因素间的差异。结果：1)参与者组别因素与测试部位、发力位置等因素均无交互作用。2)腰多裂肌的大小和物理特性在各组别间均不具有显著性差异。3)脊柱肌群最大屈伸力矩表现出2个NLBP亚组比对照组屈肌力量更大，伸肌力量更小的趋势，LSI组更甚（P> 0.05）；LSI组屈伸力矩比值大于对照组（P< 0.05）。结论：腰痛以及腰椎稳定性因素与躯干肌群的形态和物理学特性并无直接关联；力量这一机能特性中F/E比值是反映不同腰椎稳定性LBP患者与正常人机能差异的敏感指标。NLBP不是一个同质性群体，采用腰椎稳定性进行亚组划分具有一定可行性。 相似文献