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1.
Alex Bliss Jeanne Dekerle 《Measurement in physical education and exercise science》2019,23(2):118-123
Knee flexor and extensor muscular assessment via isokinetic dynamometry is common practice and established in the research literature. However, reporting assessment methodology regarding reciprocal and nonreciprocal movements is often vague or absent. Such methodological issues are crucial for accurate assessments. Therefore, knee extensor and flexor peak moment using either reciprocal movement or nonreciprocal modalities was assessed. Fifteen participants performed three blocks of five concentric muscle actions at three angular velocities [1: nonreciprocal (maximal active flexion followed by passive extension); B2: reciprocal (maximal active extension followed by maximal active flexion); B3 nonreciprocal (maximal active extension followed by passive flexion)]. ANOVA revealed statistically significant within-subject modality effects for peak knee extensor moment and flexor velocity and modality differences (p < .05). Reciprocal and nonreciprocal assessments give significantly different results, with nonreciprocal giving higher peak moments. Reporting which modality is used is crucial to allow for greater clarity for the reader and practitioner. 相似文献
2.
Kohei Watanabe Takayuki Sato Takahiro Mukaimoto Wataru Takashima Michio Yamagishi Tetsunari Nishiyama 《Journal of sports sciences》2016,34(15):1413-1422
We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles. 相似文献
3.
茜草提取物对大强度耐力训练大鼠股四头肌ATP 酶活性及运动能力影响的实验研究 总被引：2，自引：0，他引：2
目的：探讨茜草提取物对大强度耐力训练大鼠股四头肌ATP酶活性及运动能力的影响，为茜草作为运动补剂提供理论依据。方法：选取24只大鼠，随机分为安静组、训练组和训练加药组。训练组与训练加药组按照训练模型进行为期6周的耐力训练，最后一次训练进行一次力竭性运动，力竭后取股四头肌组织并进行样本处理。内容：通过建立大强度耐力训练大鼠模型，测定运动大鼠力竭运动的时间以及股四头肌ATP酶活性。研究茜草提取物对大强度耐力训练大鼠股四头肌的保护作用。结论：茜草提取物可明显提高大鼠股四头肌在大强度耐力运动中的能量供给，提高了大鼠大强度耐力运动的运动时间。 相似文献
4.
膝关节受伤以后,最早出现萎缩的肌肉是股四头肌内侧头。足球运动员膝关节伤病多,所以对其股四头肌肌粗值进行定量分析,具有实际意义。以体表形态数据建立数学模型,推导出股四头肌肌粗值,建立了统一的对比衡量标准。肌粗值的变化,首先是受髌骨上５ｃｍ 外缘腿围影响,其次是受髌中围的影响,相关程度分别为高度相关和低度相关,而肌粗值与髌骨上１０ｃｍ 外缘腿围间变化呈不相关。 相似文献
5.
Aaron T Scanlan Jordan L Fox Nattai R Borges Anne Delextrat Tania Spiteri Vincent J Dalbo 《Journal of sports sciences》2018,36(8):852-860
This study quantified lower-limb strength decrements and assessed the relationships between strength decrements and performance fatigue during simulated basketball. Ten adolescent, male basketball players completed a circuit-based, basketball simulation. Sprint and jump performance were assessed during each circuit, with knee flexion and extension peak concentric torques measured at baseline, half-time, and full-time. Decrement scores were calculated for all measures. Mean knee flexor strength decrement was significantly (P < 0.05) related to sprint fatigue in the first half (R = 0.65), with dominant knee flexor strength (R = 0.67) and dominant flexor:extensor strength ratio (R = 0.77) decrement significantly (P < 0.05) associated with sprint decrement across the entire game. Mean knee extensor strength (R = 0.71), dominant knee flexor strength (R = 0.80), non-dominant knee flexor strength (R = 0.75), mean knee flexor strength (R = 0.81), non-dominant flexor:extensor strength ratio (R = 0.71), and mean flexor:extensor strength ratio (R = 0.70) decrement measures significantly (P < 0.05) influenced jump fatigue during the entire game. Lower-limb strength decrements may exert an important influence on performance fatigue during basketball activity in adolescent, male players. Consequently, training plans should aim to mitigate lower-limb fatigue to optimise sprint and jump performance during game-play. 相似文献
6.
自行车运动时股四头肌肌电图指标与功率输出的比较研究 总被引：2，自引：0，他引：2
为了揭示运动训练对股四头肌sEMG指标与输出功率的影响,对52人次健康受试者测试30 s全力蹬踏自行车过程中的功率输出和MegaWin记录运动过程中的肌电变化。结果提示前5 s的单谱肌电图指标和后5 s单谱和平均谱与相对最大功率相关程度可反映训练水平,后5 s的单谱肌电图指标反映疲劳程度。 相似文献
7.
在客观评价肌肉功能的基础上,探讨不同针刺方法对股四头肌运动性疲劳的影响。利用表面肌电仪记录右侧股四头肌伸膝运动的动态表面肌电信号（sEMG）,并提取积分肌电值（iEMG）、中位频率（MF）。股四头肌伸膝运动sEMG原始图像显示：静息状态时,肌电信号振幅波动小,频率缓慢;运动性疲劳时,肌电信号振幅波动增大,频率加快;治疗后,浮刺组与直刺组的肌电信号振幅波动减小,频率减慢;而对照组未有明显变化。发生运动性疲劳时,iEMG值升高,MF值降低。浮刺治疗后,浮刺组股四头肌伸膝运动iEMG值较疲劳时降低,MF值较疲劳时上升。研究表明,sEMG可以作为局部肌肉运动性疲劳以及恢复效果的评价手段;针刺具有抗运动性疲劳作用;在股四头肌运动性疲劳恢复效果上浮刺优于直刺,可能与改善肌肉电生理有关。 相似文献
8.
针对国内外在电刺激法领域研究的不足,选定普通大学生、一般运动员和优秀运动员三个不同训练 水平组,进行了电刺激股四头肌并测试电刺激法训练前后膝关节伸、屈肌力矩变化的研究。结果显示,三组受 试者被刺激肌肉及其相对抗的屈肌不同速度下的等动力量均有不同程度的增加;其中普通大学生和一般运 动员组的肌力增长较电刺激法训练前有统计学显著性意义,前者的肌力增加幅度明显大于后者;而且这两组 肌力的增加显著高于优秀运动员组。 相似文献
9.
股四头肌长度和力臂的实验性研究 总被引：2，自引：0，他引：2
结合前期肌肉附着点三维坐标的研究,对股四头肌长度和力臂进行专门的实验性研究。研究髌骨对推算股四头肌长度及对膝关节力臂的影响。髌骨随膝角变化的运动轨迹特征呈抛物线状;髌骨主要对膝关节力臂有重要的影响,可使力臂长度增加2.5倍;90°～0°伸膝范围内力臂增加幅度较大。 相似文献
10.
通过观察急性运动和热预处理后急性运动对大鼠股四头肌热休克蛋白(HSP)70 表达影响的时相性变化和氧化应激标志物超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的变化,探讨HSP70对急性运动大鼠股四头肌抗氧化能力的影响和股四头肌HSP70表达的应答性反应.雄性SD大鼠随机分为室温安静组、室温运动后即刻组、室温运动后3 h组、室温运动后24 h组、热预处理安静组、热预处理运动后即刻组、热预处理运动后3 h组、热预处理运动后24 h组.热预处理组在恒温干燥箱进行热暴露处理(直肠温度达到(41.5±0.5)℃,持续15 min).安静组大鼠在热预处理24 h后对股四头肌进行取样.运动组大鼠在热预处理24 h后进行急性跑台运动(速度为25m/min,坡度为0°,时间为60 min),分别在运动后即刻、运动后3 h、运动后24 h对大鼠进行股四头肌取样,检测HSP70蛋白表达量、SOD活性和MDA含量.结果表明,大鼠急性运动后两组大鼠运动后即刻HSP70蛋白表达有上升的趋势,但差异无统计学意义(P>0.05),3 h显著增加(P<0.05),24 h后回降,室温组与基础水平相比差异无显著性(P>0.05),而热预处理组仍显著高于基础水平(P<0.05),在变化过程中热预处理组HSP70蛋白表达量显著高于室温组(P<0.05);室温组和热预处理组大鼠急性运动后即刻股四头肌SOD活性明显升高(P<0.05),3 h后活性降低,但显著高于基础水平(P<0.05),24h后回降到基础水平.在变化过程中热预处理组SOD活性显著高于室温组(P<0.05);室温组和热预处理组大鼠运动后即刻股四头肌MDA的含量显著升高(P<0.05),3h后热预处理组MDA含量恢复至基础水平,室温组含量减少,但是仍显著高于基础水平(P<0.05),室温组24 h恢复至基础水平,在变化过程中热预处理组较室温组MDA含量降低速率快(P<0.05).这些发现表明急性运动可以诱导HSP70表达增加和热预处理后进行运动可以产生HSP70表达的累加效应.诱导HSP70大量表达可能提高机体的抗氧化能力,减轻机体运动时的氧化应激损伤. 相似文献