Effect of gender on trunk and pelvis control during lateral movements with perturbed landing     

Elmar Weltin  Albert Gollhofer  Guillaume Mornieux 《European Journal of Sport Science》2016,16(2):182-189

In lateral reactive movements, core stability may influence knee and hip joint kinematics and kinetics. Insufficient core stabilisation is discussed as a major risk factor for anterior cruciate ligament (ACL) injuries. Due to the higher probability of ACL injuries in women, this study concentrates on how gender influences trunk, pelvis and leg kinematics during lateral reactive jumps (LRJs). Perturbations were investigated in 12 men and 12 women performing LRJs under three different landing conditions: a movable landing platform was programmed to slide, resist or counteract upon landing. Potential group effects on three-dimensional trunk, pelvic, hip and knee kinematics were analysed for initial contact (IC) and the time of peak pelvic medial tilt (PPT). Regardless of landing conditions, the joint excursions in the entire lower limb joints were gender-specific. Women exhibited higher trunk left axial rotation at PPT (women: 4.0 ± 7.5°, men: ?3.1 ± 8.2°; p = 0.011) and higher hip external rotation at both IC and PPT (p < 0.01). But women demonstrated higher knee abduction compared to men. Men demonstrated more medial pelvic tilt at IC and especially PPT (men: –5.8 ± 4.9°, women: 0.3 ± 6.3°; p = 0.015). Strategies for maintaining trunk, pelvis and lower limb alignment during lateral reactive movements were gender-specific; the trunk and hip rotations displayed by the women were associated with the higher knee abduction amplitudes and therefore might reflect a movement strategy which is associated with higher injury risk. However, training interventions are needed to fully understand how gender-specific core stability strategies are related to performance and knee injury.  相似文献   

The influence of shoe drop on the kinematics and kinetics of children tennis players     

Alexis Herbaut  Pascale Chavet  Maxime Roux  Nils Guéguen  Christophe Gillet  Franck Barbier 《European Journal of Sport Science》2016,16(8):1121-1129

This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12?mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p?=?.004) and the ankle was less dorsiflexed at foot strike (p?=?.037). In D0 compared with D12, the peak impact force was reduced by 17% (p?=?.049), the ankle was less dorsiflexed at foot strike (p?=?.045) and the knee was more flexed at foot strike (p?=?.007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p?=?.658) or the peak ankle plantarflexor moment (p?=?.071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries.  相似文献   

Bilateral practice improves dominant leg performance in long jump     

Anne Focke  Sina Spancken  Christian Stockinger  Benjamin Thürer  Thorsten Stein 《European Journal of Sport Science》2016,16(7):787-793

Benefits of bilateral practice both for the non-dominant and for the dominant body side have been shown in several studies. Thereby, most of the studies included movement tasks of the upper extremity or investigated sports games in which the ability of acting bilaterally is an essential basis for success and, thus, a bilateral practice is reasonable anyway. Individual unilaterally performed sports including movement tasks of the lower extremity are rarely investigated. Therefore, the aim of our study was to test if contralateral transfer due to bilateral practice can be found in an unilaterally performed sport including the lower extremity. We trained and tested 61 adolescent athletes in long jump to compare the jumping performance of the dominant leg after a 12-week practice period between two groups: a bilateral practice group that practiced specific long jump exercises with both the dominant and non-dominant leg and an unilateral practice group that practiced specific long jump exercises only with the dominant leg. Results showed a superior effect of bilateral practice compared to unilateral practice regarding the jumping performance of the dominant leg. The performance increase at post-test and retention-test for the dominant limb was significantly higher for the bilateral practice group (pre-to-post: 5.2%, pre-to-retention: 7.4%) compared to the unilateral practice group (pre-to-post: 3.4%, pre-to-retention: 4.5%). Thus, bilateral practice should be established in the early practice programmes of track and field athletes to improve the performance of the dominant take-off leg.  相似文献   

玉米在近现代长江下游山区的种植与传播     

张祥稳  戴家翠 《安庆师范学院学报(社会科学版)》2019,38(5):46-50

长江下游是中国最早传入玉米并大面积种植的地域之一。自清代康乾年间始至当代,玉米日渐在杭嘉湖、皖南、皖西南和皖东苏西山区传播种植,先后形成约40个县域种植区;玉米在长江下游的传播路径有一点两线;清代和民国时期的传种者以棚民为主、土著为辅,当代则是土著和地方政府。  相似文献   

体育训练常见急性损伤及其预防     

白晓旭 《黔东南民族师专学报》2005,23(6):42-44

依据对体育训练中常见急性损伤及其防治的调查资料，分析了造成急性损伤的原因，并对预防急性损伤的措施与手段作了的探索，力求减少急性损伤的发生，使体育锻炼更好地起到促进身心健康的作用．  相似文献   

党的十六大对社会主义初级阶段收入分配理论的丰富和发展   总被引：1，自引：0，他引：1  

杨文森 《福建师大福清分校学报》2003,(3):25-26,32

十六大报告中关于收入分配的论述立意深远。内涵丰富,充满了新思想、新观念、新论断。本文拟就按生产要素分配原则;效率优先,兼顾公平原则;“调高、扩中、提低”战略等方面来论述十六大报告对社会主义初级阶段收入分配理论的丰富和发展。  相似文献   

创伤性近侧指间关节屈曲挛缩治疗方法的探讨     

苏峰  张春林  张军威  李国通 《河北北方学院学报(医学版)》2001,(1)

目的:对创伤性近侧指间关节挛缩的发病机制和治疗方法进行探讨。方法:对1995～2000年在我院治疗的创伤性近侧指间关节屈曲挛缩病例进行回顾,指间关节挛缩的发病机制,根据关节内外粘连的不同因素进行松解手术治疗。结果:创伤性近侧指间关节屈曲挛缩的病变可分为关节内粘连、关节外粘连及复合性粘连。经过:(1)单纯松解掌板延长及屈指浅肌腱切断等手术。(2)手术加牵引术,取得了良好结果。平均改善关节活动度达100度(屈)(伸)-10度。结论:(1)创伤性近侧指间关节屈曲挛缩的发生与早期处理不当有关。(2)粘连可以是关节内或关节外因素及复合因素造成。(2)手术治疗配合术后牵引治疗可取得良好的效果。  相似文献   

关于粘性导数的几个性质的探讨     

汪元伦 《绵阳师范学院学报》2004,23(2):19-21

M .G .Crandall等人在文 [1]中给出了函数的粘性导数的概念。在这个概念的基础上我们讨论了函数的粘性导数的上 (下 )导集的几个性质 :在函数可微点处的性质、闭凸性质、与C1类函数的和的性质、与C2 类函数的差在严格局部极大 (小 )值点的性质。  相似文献   

以考古文物资源提升滦河下游区域旅游竞争力     

伍长云 《唐山师范学院学报》2011,33(1):113-115

文物考古资源是地方文化的积聚,是构建特色文化旅游产品的基础。文物和考古旅游已成为最强劲的新兴专项旅游。以滦河下游为例,分析了利用考古文物资源提升区域旅游竞争力优势,并提出了具体的对策。  相似文献   

Collaborative research for sustainable learning: the case of developing innovation capabilities at Volvo Cars   总被引：1，自引：1，他引：0  

Sofia Börjesson 《Action Learning: Research and Practice》2011,8(3):187-209

This paper aims to make a contribution to the stream of literature on action research by describing a longitudinal collaborative research project which evolved out of a long-term, participation partnership with Volvo Cars. The collaboration was aimed at developing innovation capabilities in the company and accumulating knowledge on how capabilities are developed. The paper provides insights into the design of collaborative research projects to enable mutual, sustainable learning. It draws on key notions in the literature on collaborative management research and action learning, highlighting the research design of the project at Volvo Cars and its relations to action learning. The paper describes how the research design opened the way to establishing a learning system at Volvo Cars while simultaneously generating new scientific knowledge within the area of innovation capabilities. The paper provides rich and detailed data on a collaborative research setting and highlights key aspects related to organizing and undertaking collaborative research.  相似文献