Kinematic effects of repeated turns while running     

《European Journal of Sport Science》2013,13(8):1072-1081

Abstract

In team sports, non-contact ACL and MCL injuries occur during abrupt changes of direction, like turns or cutting manoeuvres. Fatigue affects dynamic neuromuscular control and increases knee injury risk. This study analysed how lower limb joints and centre-of-mass kinematics are affected throughout a high-intensity running protocol involving repeated 180°-turns. Twenty young men (18–23 years, BMI: 20.8–24.4?kg?m^?2) completed a 5-m shuttle running trial lasting 5?min at an average speed of 75% of their maximum aerobic speed. During the test, cardio-metabolic parameters were obtained, together with joints and centre-of-mass kinematics, using a motion capture system. Kinematic data were compared between the first and the last minute of exercise. Perceived exercise intensity ranged from “hard” to “maximum exertion” and post-exercise lactate concentration ranged from 5.4 to 15.5?mM. The repetition of 180°-turns induced a substantial reduction of hip (?60%, p?<?.001, large effect) and knee flexion (?40%, p?=?.003, medium-to-large effect), and an increase of hip adduction and internal rotation (+25–30%, p?<?.05, medium-to-large effect). Since such movements are factors increasing the likelihood of non-contact knee injuries, we concluded that the prolonged repetition of turns may expose participants to increased risk of ligament failure. Prevention programmes should include discipline-specific neuromuscular training especially in late practices.  相似文献   

运动对骨骼肌线粒体生物合成调节因子影响进展研究     

王震 《吉林体育学院学报》2013,(4):93-97

运动激活细胞信号诱导线粒体生物合成,不仅可以有效地增加线粒体体积、提高ATP供能能力和延缓运动性疲劳发生,还可预防与年龄相关的退行性改变而导致肌肉功能下降。随年龄增长且运动时间减少,线粒体通道受损导致有氧功能减退和细胞凋亡趋势增加可导致肌肉功能下降。通过选择合适的运动方式,能改善这种代谢功能障碍,维持肌肉质量。  相似文献   

对膝内侧副韧带损伤盘坐康复效果的观察     

陶胜国 《精武》2013,(35):7-8

观察盘坐对大学生运动员膝关节内佣副韧带损伤康复疗效。方法：将52例膝关节内例副韧带损伤大学生运动员随机分为两组。两组前期均采用针刺、推拿、TDP灯照射等方法进行治疗,待症状好转后,均进行15天的康复训练,实验组26例采用盘坐法康复,对照组26倒采用常规方法进行康复治疗。结果：实验组改良Lysholmscale评分积分值98．89,对照组分值86．42,差异有统计学意义（P〈0．01）。结论：盘坐较常规康复训练方法对膝关节内佣副韧带损伤彻底康复效果显著。  相似文献   

浅析运动创伤障碍修复治疗研究     

李奕华 《湖北体育科技》2013,32(6):498-500

经络与经筋结合孔穴对运动损伤的治疗方法和原理遵循人体经络系统的运行规律和走向,以达到康复的目的,因此是无创伤、无后遗症的健康绿色疗法。  相似文献   

试论体育教学中的伤害风险及其管理     

问梅  李俊 《湖北体育科技》2013,(11):1008-1011

高校体育教学中意外伤害事故以及引发的法律纠纷,不仅影响了学生上体育课的积极性,更给学校体育部门特别是一线体育教师带来了极大的困惑,在一定程度上影响了体育教学质量的提高。从理论上研究体育教学中的伤害风险,有助于提高学校体育部门、教师、学生对伤害风险的认识,加强防范意识,对体育教学中的伤害进行有效的防控和管理,提高教学效果具有指导意义。  相似文献   

中学生在运动训练中运动损伤情况调查分析     

孙亚男 《搏击·武术科学》2013,(1):122-124

文章采用问卷调查法、文献资料法和数理统计法,对苏尼特右旗综合高中运动队中的运动损伤的原因、运动损伤的项目、运动损伤的身体部位以及预防措施进行了调查与分析。运动损伤对运动员所造成的影响是相当严重的,不仅影响正常的训练、比赛,还妨碍运动成绩提高,减短运动寿命,严重的还可能导致残废,甚至死亡。所以无论是运动员还是教练员都切实做好预防工作,从而最大限度地减少或避免运动损伤。  相似文献   

后奥运时代民族传统体育文化的发扬与传承     

庄文杰 《搏击·武术科学》2013,(4):67-68,86

文章采用文献资料法、逻辑辩证法、对比分析法等研究方法,从文化人类学视角审视民族传统体育的价值与功能,旨在寻求民族传统体育发展道路与方法。研究结论指出：后工业时代人类对人文精神的呼唤,及对休闲娱乐生活方式的强烈渴求,都在呼唤偏重养生、顺应自然、休闲娱乐的中国民族传统体育文化的理性回归。并提出建议：民族传统体育文化发扬传承有赖于民众深层次意识里本土化觉醒,以及教育作为民族传统体育发扬传承的主战场。  相似文献   

Effect of time-of-day-specific strength training on maximum strength and EMG activity of the leg extensors in men     

Milan Sedliak  Taija Finni  Jussi Peltonen  Keijo Häkkinen 《Journal of sports sciences》2013,31(10):1005-1014

Abstract

In this study, we examined the effects of time-of-day-specific strength training on maximum strength and electromyography (EMG) of the knee extensors in men. After a 10-week preparatory training period (training times 17:00–19:00 h), 27 participants were randomized into a morning (07:00–09:00 h, n = 14) and an evening group (17:00–19.00 h, n = 13). Both groups then underwent 10 weeks of time-of-day-specific training. A matched control group (n = 7) completed all testing but did not train. Unilateral isometric knee extension peak torque (MVC) and one-repetition maximum half-squat were assessed before and after the preparatory training and after the time-of-day-specific training at times that were not training-specific (between 09:00 and 16:00 h). During training-specific hours, peak torque and EMG during MVC and submaximum isometric contraction at 40% MVC were assessed before and after the time-of-day-specific training. The main finding was that a significant diurnal difference (P < 0.01) in peak torque between the 07:00 and 17:00 h tests decreased after time-of-day-specific training in the morning group but not in the evening or control groups. However, the extent of this time-of-day-specific adaptation varied between individuals. Electromyography during MVC did not show any time-of-day-specific adaptation, suggesting that peripheral rather than neural adaptations are the main source of temporal specificity in strength training.  相似文献   

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise     

Simon Marwood  Jo Bowtell 《Journal of sports sciences》2013,31(10):1081-1090

Abstract

Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g · kg body mass^?1 of glutamine in 5 ml · kg body mass^?1 placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO₂ = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake ([Vdot]O_2max) immediately before completing a brief high-intensity time-trial (～4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (Δ[Vdot]O_2max, P = 0.02) and exercise performance (control: 243 s, s _x  = 7; glutamine: 242 s, s _x  = 3; hyperoxia: 231 s, s _x  = 3; hyperoxia + glutamine: 228 s, s _x  = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased Δ[Vdot]O_2max in normoxia, but not hyperoxia (interaction drink/FiO₂, P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise.  相似文献   

Transfer of momentum from different arm segments to a light movable target during a straight punch thrown by expert boxers     

N C. Spurway  B Ekblom  T D. Noakes  P D. Wagner 《Journal of sports sciences》2013,31(6):517-531

Abstract

Three modern views about the factors limiting oxygen uptake in healthy humans are set against the original (early 1920s) concept of A. V. Hill and colleagues. The majority view for most of the intervening time has been that cardiac output is the essential limiting function. Among recent research in support of this contention is that, in quadrupeds, pericardiectomy, which allows greater diastolic filling, elevates maximum oxygen uptake; however, the relevance to bipedal exercise can be questioned. In any case, algebraic analyses of model systems indicate that all identifiable stages on the oxygen transport pathway, from pulmonary diffusion to oxidative phosphorylation in skeletal muscle mitochondria, materially influence maximum uptake. Thus, if a high cardiac output is to be of benefit, all the other steps must function better too. Nevertheless, these two viewpoints concur that the limit to maximum oxygen uptake is somatic. In contrast, there are strong indications that at altitudes where oxygen availability is about half that at sea level, cerebral oxygenation is a limiting factor, and some recent experiments raise the possibility that it might be a substantial influence at sea level also. Clearly, consensus cannot yet be reached on the question posed in the title.  相似文献