Validation of the Microsoft Kinect® camera system for measurement of lower extremity jump landing and squatting kinematics     

Moataz Eltoukhy  Adam Kelly  Chang-Young Kim  Hyung-Pil Jun  Richard Campbell 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(1):89-102

Cost effective, quantifiable assessment of lower extremity movement represents potential improvement over standard tools for evaluation of injury risk. Ten healthy participants completed three trials of a drop jump, overhead squat, and single leg squat task. Peak hip and knee kinematics were assessed using an 8 camera BTS Smart 7000DX motion analysis system and the Microsoft Kinect® camera system. The agreement and consistency between both uncorrected and correct Kinect kinematic variables and the BTS camera system were assessed using interclass correlations coefficients. Peak sagittal plane kinematics measured using the Microsoft Kinect® camera system explained a significant amount of variance [Range_hip = 43.5–62.8%; Range_knee = 67.5–89.6%] in peak kinematics measured using the BTS camera system. Across tasks, peak knee flexion angle and peak hip flexion were found to be consistent and in agreement when the Microsoft Kinect® camera system was directly compared to the BTS camera system but these values were improved following application of a corrective factor. The Microsoft Kinect® may not be an appropriate surrogate for traditional motion analysis technology, but it may have potential applications as a real-time feedback tool in pathological or high injury risk populations.  相似文献   

Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners     

Daniel Kuhman  Daniel Melcher 《European Journal of Sport Science》2016,16(4):433-440

The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6?min?mile^?1) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations.  相似文献   

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   

Understanding the consequences of victory amongst sport spectators: The mediating role of BIRGing     

Iouri Bernache-Assollant  Yves Chantal  Patrick Bouchet  Marie-Françoise Lacassagne 《European Journal of Sport Science》2016,16(6):719-725

Prior work on the relationships between team identification and spectators’ reactions to one's team victory has largely neglected the potential effects of mediating variables. In this research, we proposed that the process of Basking in Reflected Glory [BIRGing – the tendency to reduce the distance between oneself and one's team; Cialdini, R. B., Bordon, R. J., Thorne, A., Walker, M. R., Freeman, S., &; Sloan, L. R. (1976). Basking in reflected glory: Three (football) field studies. Journal of Personality and Social Psychology, 34, 366–375] would lead spectators to almost take ownership of victories and share its benefits, thereby impacting their sense of national belonging in a positive manner. To this end, participants (N?=?73) were asked to watch an edited video clip showing a victory of the French national rugby team playing against South Africa. As expected, results revealed that BIRGing mediated the relationship between team identification and one's sense of national belonging. In closing, a number of implications are discussed along with future research avenues pertaining to the sport spectatorship literature.  相似文献   

一种提高掌纹识别率方法的研究     

吴攀 《教育技术导刊》2007,(3)

掌纹识别是利用人的手掌掌纹图像对其身份进行认证的一种生物特征识别技术,有着巨大的发展潜力。掌纹线中的主线和皱褶是重要的特征,在空间域内掌纹图像中纹理的疏密和深浅,与频域内能量聚集和紧密程度相关。目前的掌纹研究主要集中在就一种掌纹特征的提取算法上如何提高匹配率,而对结合两种以及两种以上的掌纹特征的提取算法,如何提高掌纹识别匹配率的讨论较少。提出了一种有效提高掌纹识别率的方法,即结合点特征的提取和傅立叶变换特征的提取,提高掌纹特征匹配识别率。将该方法与单独使用点特征提取和傅立叶变换提取进行了比较实验,实验结果证明新方法的识别率有明显提高。  相似文献   

墨子尚同说的专制性特征解析——兼及尚同说对韩非君主专制思想的影响   总被引：1，自引：0，他引：1  

高建立 《河南师范大学学报(哲学社会科学版)》2005,32(1):16-19

春秋战国之际，墨子针对国与国之间的战争给社会和人民带来的危害，提出了“兼爱”“非攻”的主张，但是，墨子认识到仅仅靠“兼爱”“非攻”的道德说教是不能奏效的，没有一个得到普遍承认和服从的政治权威，不能建立一种新的稳定的政治秩序，要想实现社会的稳定是不可能的，因此墨子提出了“尚同”说，即“一同天下之义”，以最高统治者的是非为根本标准，按照最高统治者的意思行事，“上之所是，必皆是之；上之所非，必皆非之”，对最高统治者即天子的权威要无条件地服从。墨子的“尚同说”具有明显的专制主义特征。“尚同”学说，从古代中国统一的意义上讲具有积极意义，反映了要求制止战争、以达统一的愿望，但是，其学说自身的矛盾性，使他的“尚同”思想抹上了比较浓重的专制主义色彩，并且对后世产生了深刻的影响。韩非作为法家代表人物，继承了墨子的尚同说，建构了封建专制主义集权思想。  相似文献   

汉字形旁类化研究   总被引：3，自引：0，他引：3  

毛远明 《西南师范大学学报(人文社会科学版)》2006,32(6):173-177

形音性质的汉字，在使用状态下，受上下文字形、字义的影响，出现大量的形旁类化字，对汉字系统的变化、汉字与它记录的词语的对应关系、汉字的写词显义功能等方面都产生了较大的影响。形旁类化字与假借字、区别字形式相同，而实质不同。讨论汉字形旁类化问题是汉字发展史研究的一项重要任务。  相似文献   

健美操运动损伤之初探   总被引：2，自引：0，他引：2  

黄艳红 《株洲师范高等专科学校学报》2002,7(5):43-45

近年来，我国健美操运动如雨后春笋迅速发展，但起步较晚，又受物质条件及其科研工作滞后等因素影响；训练中常出现各种损伤，影响了运动技术水平的提高和受训学生的身心健康，通过对武汉体院122名健美操专选班学生参加健美操训练的调查，探索研究了健美操运动损伤规律及预防措施，为受训学生创造最佳成绩，最大限度延长其运动年限，减少伤病事故发生，以及为体育院校顺利完成健美操专业训练课程及其选修课程提供参考依据。  相似文献   

运动损伤的机体康复与心理恢复   总被引：1，自引：0，他引：1  

张镇 《齐齐哈尔师范高等专科学校学报》2002,21(3):66-68

运动损伤在体育教学和训练中经常发生，本就如何科学的进行机体康复和心理恢复进行了描述，旨在使伤早日康复。  相似文献   

福建省游泳场馆游泳者风险管理问题研究     

寇健忠 《洛阳师范学院学报》2011,30(11):113-116

结合福建省游泳场馆游泳者现状,采用多种方法游泳者风险及游泳场馆溺死问题进行研究,旨在建立游泳场馆安全管理体系.研究结果表明,游泳场馆游泳者风险源包括23个风险因素,福建省游泳场馆游泳者面临12个主要风险因素,游泳场馆可以采用风险避免、风险控制、风险转移和风险自留四种方法应对游泳者风险.  相似文献