Corticospinal changes induced by fatiguing eccentric versus concentric exercise     

Yoann M. Garnier  Christos Paizis  Romuald Lepers 《European Journal of Sport Science》2019,19(2):166-176

The present study assessed neuromuscular and corticospinal changes during and after a fatiguing submaximal exercise of the knee extensors in different modes of muscle contraction. Twelve subjects performed two knee extensors exercises in a concentric or eccentric mode, at the same torque and with a similar total impulse. Exercises consisted of 10 sets of 10 repetitions at an intensity of 80% of the maximal voluntary isometric contraction torque (MVIC). MVIC, maximal voluntary activation level (VAL) and responses of electrically evoked contractions of the knee extensors were assessed before and after exercise. Motor evoked potential amplitude (MEP) and cortical silent period (CSP) of the vastus medialis (VM) and rectus femoris (RF) muscles were assessed before, during and after exercise. Similar reductions of the MVIC (?13%), VAL (?12%) and a decrease in the peak twitch (?12%) were observed after both exercises. For both VM and RF muscles, MEP amplitude remained unchanged during either concentric or eccentric exercises. No change of the MEP amplitude input–output curves was observed post-exercise. For the RF muscle, CSP increased during the concentric exercise and remained lengthened after this exercise. For the VM muscle, CSP was reduced after the eccentric exercise only. For a similar amount of total impulse, concentric and eccentric knee extensor contractions led to similar exercise-induced neuromuscular response changes. For the two muscles investigated, no modulation of corticospinal excitability was observed during or after either concentric or eccentric exercises. However, intracortical inhibition showed significant modulations during and after exercise.  相似文献   

跆拳道后旋踢技术动作的运动学特征分析          下载免费PDF全文

杨小芳 《河北体育学院学报》2016,30(3):81-85

采用三维高速摄像技术和运动生物力学原理,对后旋踢技术身体重心移动、动作所用时间、踝关节角度、膝关节角度和髋关节角度的运动学特征进行比较分析,得出结论:踢击腿在离地瞬间身体重心要快速向回旋方向移动;踢击腿膝关节最大程度弯曲,以缩短动作时间、加快踢击速度;踢击腿髋关节只有最大程度地弯曲,弯曲的膝关节才能快速展开;踢击腿的髋关节最大程度弯曲再打开时,踝关节能快速鞭打;支撑腿弯曲后在踢击腿踢出的瞬间,髋关节开始伸展,将对打击高度产生影响;踢击腿膝关节和髋关节最大程度弯曲时能增加击打力度.  相似文献   

膝关节贴扎技术的临床应用研究进展          下载免费PDF全文

姜敏  陈文华  余波 《体育科研》2017,(5):94-97

膝关节疾病易发多见,贴扎技术作为主要的非侵入性治疗技术也已广泛应用于临床。结合各类膝关节受累疾病总结了近年贴扎相关的临床应用研究进展,为贴扎技术改善膝关节各类主诉尤其是运动功能障碍方面提供一定参考。  相似文献   

The Dutch language anterior cruciate ligament return to sport after injury scale (ACL-RSI) – validity and reliability     

Anton J. Slagers  Inge H. F. Reininga  Inge van den Akker-Scheek 《Journal of sports sciences》2017,35(4):393-401

The ACL-Return to Sport after Injury scale (ACL-RSI) measures athletes’ emotions, confidence in performance, and risk appraisal in relation to return to sport after ACL reconstruction. Aim of this study was to study the validity and reliability of the Dutch version of the ACL-RSI (ACL-RSI (NL)).

Total 150 patients, who were 3–16 months postoperative, completed the ACL-RSI(NL) and 5 other questionnaires regarding psychological readiness to return to sports, knee-specific physical functioning, kinesiophobia, and health-specific locus of control. Construct validity of the ACL-RSI(NL) was determined with factor analysis and by exploring 10 hypotheses regarding correlations between ACL-RSI(NL) and the other questionnaires. For test–retest reliability, 107 patients (5–16 months postoperative) completed the ACL-RSI(NL) again 2 weeks after the first administration. Cronbach’s alpha, Intraclass Correlation Coefficient (ICC), SEM, and SDC, were calculated. Bland–Altman analysis was conducted to assess bias between test and retest.

Nine hypotheses (90%) were confirmed, indicating good construct validity. The ACL-RSI(NL) showed good internal consistency (Cronbach’s alpha 0.94) and test–retest reliability (ICC 0.93). SEM was 5.5 and SDC was 15. A significant bias of 3.2 points between test and retest was found.

Therefore, the ACL-RSI(NL) can be used to investigate psychological factors relevant to returning to sport after ACL reconstruction.  相似文献   

优秀散打运动员下肢关节等速肌力特征研究     

王聚龙  刘存忠  王宏 《武汉体育学院学报》2019,53(1):92-97

运用IsoMed2000型肌力测试系统，选择60°/s和240°/s，对23名优秀男子散打运动员（健将级9名为A组，国家一级14名为B组）支撑腿和进攻腿髋、膝、踝屈伸肌群各项等速肌力指标进行测量。探讨优秀散打运动员支撑腿和进攻腿髋、膝、踝关节等速肌力特征，分析两腿的肌力差异，判断肌力平衡、关节稳定，运动员等级水平对肌力的影响。结果：国家健将级散打运动员双侧下肢髋、膝、踝关节等速肌力及稳定性显著优于国家一级运动员，支撑腿主要体现力的有效传递及稳定性，进攻腿主要体现屈伸肌力大小。  相似文献   

Associated ACL risk factors differences during an unanticipated volleyball blocking movement     

David Zahradnik  Daniel Jandacka  Gabriela Beinhauerova  Joseph Hamill 《Journal of sports sciences》2020,38(20):2367-2373

ABSTRACT

The lateral tilt of the arms accompanied by trunk lateral tilt is a typical blocking manoeuvre in volleyball. However, during this unanticipated blocking movement, an associated risk of ACL injury may result. The aim of the present study was to compare associative ACL risk factors at the initial contact and the first and second peak of VGRF during an unanticipated blocking movement with different arm positions. Synchronized kinematic and kinetic data were collected for each trial of each condition. Student paired t-tests and effect size were used to determine differences between two conditions (S – with arms straight up from the body) and (T – with the arms and trunk laterally tilted). The results showed that the T condition significantly decreases knee flexion, increases VGRF at the foot contact, first peak force and increases the valgus moment at the first peak force. The values of the associated risk factors for a non-contact ACL injury appear to be related to the tilted arm position accompanied by trunk tilt towards to right lower limb during landing. The players should be taught to land with greater knee flexion and, if possible, a double-leg landing to decrease right lower limb loading during the blocking manoeuvre.  相似文献   

膝关节ACL损伤关节镜术后早期康复计划研究   总被引：6，自引：0，他引：6  

杨时  严明  林勇 《体育科研》2003,24(6):42-45

采用实验法,对专业运动员膝关节前交叉韧带及半月板关节镜修补手术后的康复运动训练进行研究,结果显示,本研究中制定的康复计划,在运动员客观症状改善和运动能力恢复方面均优于传统的临床实践,具有损伤后运动竞技能力尽早恢复的可行性。  相似文献   

短跑运动员专项力量训练的新思路   总被引：1，自引：0，他引：1  

黄希斌 《闽江学院学报》2008,29(5)

如何设计和选择专项力量训练手段,取决于教练对专项技术和力量本质特征的正确认识．现代短跑运动员技术的本质特征应视以髋为轴的高速摆动一平动运动．短跑专项力量训练是当代力量训练的核心,发展短跑专项力量不仅应采用负重的专项练习,而且更重要的是改进杠铃训练使其在练习形式、负荷和力度尽可能接近专项．  相似文献   

太极拳运动中的足底压力分布研究     

杨春荣 《北京体育大学学报》2007,30(5):645-647

该研究对16名优秀太极拳练习者的5个典型太极动作的脚底9个区域的压力分布数据进行了采集和分析,结果表明:在太极拳运动中,脚底第1跖骨头和第1脚趾的压力载荷显著大于其它部位(P＜0.05);在太极拳的向前、向后和左右脚步动作中,足底压力中心的内外侧方向上的位移显著大于正常步行(P＜0.05);在太极拳的向前脚步移动中,足底压力中心的前后侧方向上的位移显著大于正常步行(P＜0.05).该研究认为太极拳运动的足底压力分布特征可能是造成太极拳运动能够提高平衡和控制肌肉力量的重要因素之一.  相似文献   

对不同训练水平短跑运动员相关肌群变化规律的研究     

徐开春  高航  关雨田 《吉林体育学院学报》2007,23(1):93-94

通过对不同训练水平短跑运动员相关肌群变化规律的探索,揭示出不同训练水平短跑运动员肌肉工作特点及内在联系,明确各肌群力量素质的合理比例,为今后短跑运动教学与训练提供参考和咨询.  相似文献