共查询到19条相似文献，搜索用时 243 毫秒
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我们用兔抗人α-actinin(α-辅肌动蛋白)抗血清和羊抗兔IgG-胶体金复合物作为标记物,在由Lowicryl K4M包埋的组织超薄切片上定位Z带蛋白α-actinin。在大负荷斜蹲后48小时从6名男性受试者(年龄为22—22岁)的两侧腿股外肌中取得活检样品,并在运动后不同时刻及活检取样前对随机确定的每一受试者的一条腿进行针刺或静力牵张,另一侧腿作对照。结果发现,针刺或静力牵张腿Z带特异性标记密度比其对照腿高。此外,针刺或静力牵张还能使Z带发生超微结果的变化率分别减少36％和22％,并使显著变化的比例减少,轻度变化的比例增加。以上观察结果揭示了针刺或静力牵张能抑制由于α-actinin的解聚或降解引起的Z带超微结构变化过程,或者通过加速α-actinin的聚合或合成而促进Z带超微结构的恢复。 相似文献
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针刺和静力牵张对大负荷运动后骨骼肌收缩结构变化影响的免疫电镜研究 总被引：2，自引：0，他引：2
用免疫电镜的方法观察大负荷运动后骨骼肌收缩结构变化时M蛋白、α-辅肌动蛋白和肌球蛋白的定位,以探索超过习惯负荷后收缩结构延迟性变化的性质,以及针刺和静力牵张对促进其恢复的机理,结果发现:在多组力竭性工作后,收缩结构发生变化的同时,伴有该结构的免疫标记密度下降以及有关收缩蛋白的免疫标记向其结构以外区域扩散,这一结果提示:超过习惯负荷后收缩结构变化或解体是由于延迟性的收缩蛋白的降解优势所致。由于这种变化是一过性的,经过休息和调整训练负荷即可能恢复,并未形成稳定的改变,因而其性质仍可认为是生理性的或是生理向病理性变化的过渡状态。针刺和静力牵张能通过加强收缩蛋白的合成代谢而有效地促进收缩结构的恢复并出现疼痛的消除,其作用的机理尚待进一步的研究。 相似文献
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力竭运动对大鼠骨骼肌自由基代谢及肌细胞膜通透性的影响 总被引：20，自引：0，他引：20
以大鼠急性递增负荷运动至力竭为模型,观察运动后大鼠骨骼肌形态学改变与自由基损伤的关系。结果表明:力竭性运动后骨骼肌脂质过氧化水平显著增高,至运动后48 h 仍未恢复;骨骼肌形态改变主要表现为肌纤维膜通透性增高,线粒体肿大,Z线异常,肌原纤维降解,并以运动后24～48 h 最为严重。脂质过氧化程度与骨骼肌超微结构改变有密切关系。运动后自由基生成增多是骨骼肌结构破坏的直接因素,更是其形态进一步改变的激发因素。 相似文献
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枸杞是运动员饮食中常用的营养补剂,对运动后体能恢复、免疫能力提高等具有重要作用。为了研究补充枸杞对力竭运动后大鼠骨骼肌超微结构变化的影响,对Wistar大鼠6周枸杞灌喂后进行一次性力竭运动,观察运动后即刻、24 h、48 h、72 h的大鼠比目鱼肌超微结构变化。发现力竭运动导致大鼠比目鱼肌在运动后即刻至48 h间超微结构出现显著变化,表现为Z线的紊乱、肌纤维断裂、线粒体结构改变及肌核内移等现象。表明补充枸杞能显著改善力竭运动后即刻至48 h比目鱼肌超微结构损伤,加速骨骼肌超微结构损伤恢复。 相似文献
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于滢 《哈尔滨体育学院学报》2016,(4):15-20
目的:观察一次离心运动对骨骼肌线粒体动力学相关蛋白的变化,并探究针刺干预对其影响.方法:将SD大鼠分为安静对照、针刺、一次离心运动和运动针刺四大组.运动方式采取下坡跑,坡度-16°,速度16m/min,时间90min;针刺方法小腿三头肌纵向从远端斜刺,进针角度约30°,进针止于小腿三头肌肌腹处,留针2min.各组又按运动后时相点分为0h、6h、12h、24h、48h和72h小组,大鼠在对应时间点取比目鱼肌进行检测.Western Blot法检测针刺干预及一次运动后不同时程后线粒体动力学相关蛋白Mfn2、Drp1的蛋白表达.结果:单纯针刺后Mfn2蛋白表达上调,Drp1在12h出现显著上调.单纯运动组Drp1在0h出现显著降低.与运动组相比较,运动针刺后Mfn2在0h、24h有显著变化.Drp1蛋白表达在0h、12h有显著变化.结论:一次离心运动早期使骨骼肌线粒体出现分裂抑制.针刺可以改善一次离心运动导致的骨骼肌线粒体动力学状态,进而影响线粒体分布与功能. 相似文献
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一次力竭性离心运动后大鼠骨骼肌α-actin代谢变化及针刺对其影响 总被引：4，自引：0，他引：4
为了研究一次力竭性离心运动后大鼠骨骼肌肌动蛋白（α-actin）代谢变化及针刺对其影响，将130只成年SD大鼠随机分为安静对照组和运动实验组。将运动实验组又分为非针刺组和针刺组。将非针刺组和针刺组根据运动后的不同取样时间分别分为：运动后即刻组、6h组、12h组、24h组、48h组和72h组。运动组大鼠动物在跑台上以16m/min的速度进行持续性下坡跑至力竭。在一次力竭性离心运动后即刻，对针刺组大鼠进行针刺，安静对照组和非针刺组不进行针刺处理。分别在运动后即刻6、12、24、48、72h取大鼠的股四头肌，利用Dnase I抑制法测定了大鼠肌骼肌单体肌动蛋白（G-actin）、纤维状肌动蛋白（F-actin）和总肌动蛋白（T-actin）的含量。和安静对照组相比，一次力竭性离心运动后大鼠骨骼肌T-actin含量没有明显变化，G-actn含量只在运动后即刻显著低于安静对照组，F-actin含量在运动后即刻到运动后6小时，高于安静对照组，运动后12～24h降低到低于安静对照组水平。出现延迟性F-actin解聚加强现象。运动后即刻到运动后6h，针刺组大鼠骨骼肌F-actin的升高幅度低于非针刺组，而在运动后12～24h显著高于非针刺组，说明针刺对大负荷运动后大鼠骨骼肌F-actin的含量有调节作用，而且，这种调节作用可能是双向的，针刺可以阻遏大负荷运动引起的F-actim，延迟性解聚加强。 相似文献
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通过建立大鼠下坡跑运动损伤模型,研究运动损伤后骨骼肌超微损伤和恢复发生的机制。主要结果:运动后大鼠肱三头肌超微结构发生改变,电镜下可见肌纤维排列紊乱,Z线异常(包括Z线流、Z线模糊、Z线扭曲和Z线消失),肌细胞膜模糊、溶解,线粒体肿胀、空泡样改变等。这些现象随运动时间的不同而发生改变。运动后24 h表现最为明显,而后逐渐恢复;运动后72 h恢复明显,但没有完全恢复。运动后即刻血清CK活性(2035.42±426.49)U/L与对照组血清CK活性(293.66±76.07)U/L相比,非常显著增高(P<0.01),达到了峰值,而后逐渐恢复。运动后72h组血清CK活性(425.51±143.34)U/L与即刻组血清CK活性相比已显著恢复(P<0.01)。结论:运动后24h骨骼肌的损伤程度最为严重,72 h后可明显恢复;大强度运动对CK的活性具有非常显著的影响,血清CK活性的变化能够反映运动后骨骼肌超微结构损伤的状况。 相似文献
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通过采用银针加艾灸的方法,对106名运动员急慢性软组织损伤的治疗效果进行观察,发现疗效优良者占80.19％,中占16.98％,差占2.83％。由于银针的针体较粗,导热性能良好,针灸后可改善受伤部位微循环,具明显镇痛作用,疗效较好。 相似文献
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通过采用银针加艾灸的方法,对106名运动员急慢性软组织损伤的治疗效果进行观察,发现疗效优良者占80.19％,中占16.98％,差占2.83％。由于银针的针体较粗,导热性能良好,针灸后可改善受伤部位微循环,具明显镇痛作用,疗效较好。 相似文献
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目的:测试静态拉伸训练前、后男性青年排球运动员踝关节跖-背屈动作和落地缓冲动作生物力学参数,分析静态拉伸对踝关节动力学及下肢缓冲特征影响的机制及意义。方法:22名健康男性青年高水平排球运动员随机分为实验组和对照组,对实验组进行36组下肢静态拉伸训练。分别于训练前、12组训练后、24组训练后、36组训练后、停训4周恢复期后测试踝关节跖-背屈动力学和缓冲期下肢及下肢各关节动力学、运动学数据,同步测试小腿后肌群影像学。结果:12组训练后至恢复期踝关节跖-背屈范围增加非常显著(P<0.01),小腿后肌群被动刚度显著降低(P<0.05),二者的增加/降低率%于36组训练后改变最明显(P<0.05),且变化率%之间呈非常显著正相关(P<0.01)。训练后小腿后肌群滞后%明显降低(P<0.05),肌腱弹性回缩率%明显升高(P<0.05),且二者之间呈显著负相关(P<0.05)。下肢刚度显著降低(P<0.05),髋、膝、踝关节做功均显著增加(P<0.05),训练各阶段踝关节做功贡献度均最大(P<0.05)。结论:静态拉伸训练早期即可通过降低肌肉-肌腱复合体被动刚度而增加关节活动范围和通过降低滞后而提高肌腱弹性回缩率并保持至恢复期,提示,静态拉伸训练急性期和慢性期均能提高肌肉-肌腱复合体的柔韧性及肌腱的弹性能利用率,从而有利于提高拉长-缩短周期运动表现。训练后各阶段下肢刚度降低的同时各关节缓冲吸能增加且踝关节是吸能的主要部位,提示,静态拉伸可通过调整缓冲模式、提高关节能量吸收、增效踝关节作用降低排球运动员下肢损伤的风险。 相似文献
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《European Journal of Sport Science》2013,13(1):41-49
Abstract We investigated the effects of static stretch duration on peak isometric plantarflexor moment and passive ankle moment in seven healthy volunteers. After the passive ankle plantarflexor moment was recorded on an isokinetic dynamometer, the peak isometric ankle moment was measured with simultaneous electromyographic monitoring of the medial gastrocnemius. The participants subsequently performed a single 5-s stretch, a single 15-s stretch, four 5-s stretches, four 15-s stretches or no stretch (control) before being re-tested. All participants randomly completed each condition with a 24-h rest between tests. The main finding of the study was a significant correlation between reductions in peak moment and stretch duration (r=0.68; P<0.05), which became significantly different from the control group after four 15-s stretches (16.7%, s=5.3; P<0.05). There was a similar decrease in passive moment (20.9%, s=1.3; P<0.05) after each stretch condition, but this was not accompanied by a change in hysteresis. The electromyographic activity recorded during maximal plantarflexion did not change significantly after stretching. Our results are the first to show a duration-dependent effect of stretch on force (moment) production of the plantarflexors. Further research is required to elucidate the mechanisms responsible, as alterations in the stiffness properties of the muscle–tendon complex or muscle recruitment cannot completely explain the changes. 相似文献
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Literature concerning the theoretical role of spinal reflex circuits and their sensorimotor signals in proprioceptive neuromuscular facilitation (PNF) muscle stretching techniques was examined. Reviewed data do not support the assertion commonly made in PNF literature that contraction of a stretched muscle prior to further stretch, or contraction of opposing muscles during muscle stretch, produces relaxation of the stretched muscle. Further, following contraction of a stretched muscle, inhibition of the stretch reflex response lasts only 1 s. Studies examined suggested that decreases in the response amplitude of the Hoffmann and muscle stretch reflexes following a contraction of a stretched muscle are not due to the activation of Golgi tendon organs, as commonly purported, but instead may be due to presynaptic inhibition of the muscle spindle sensory signal. The current view on the complex manner by which the spinal cord processes proprioceptive signals was discussed. The ability of acute PNF stretching procedures to often produce a joint range of motion greater than that observed with static stretching must be explained by mechanisms other than the spinal processing of proprioceptive information. Studies reviewed indicate that changes in the ability to tolerate stretch and/or the viscoelastic properties of the stretched muscle, induced by PNF procedures, are possible mechanisms. 相似文献
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Gordon Chalmers 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):159-183
Literature concerning the theoretical role of spinal reflex circuits and their sensorimotor signals in proprioceptive neuromuscular facilitation (PNF) muscle stretching techniques was examined. Reviewed data do not support the assertion commonly made in PNF literature that contraction of a stretched muscle prior to further stretch, or contraction of opposing muscles during muscle stretch, produces relaxation of the stretched muscle. Further, following contraction of a stretched muscle, inhibition of the stretch reflex response lasts only 1 s. Studies examined suggested that decreases in the response amplitude of the Hoffmann and muscle stretch reflexes following a contraction of a stretched muscle are not due to the activation of Golgi tendon organs, as commonly purported, but instead may be due to presynaptic inhibition of the muscle spindle sensory signal. The current view on the complex manner by which the spinal cord processes proprioceptive signals was discussed. The ability of acute PNF stretching procedures to often produce a joint range of motion greater than that observed with static stretching must be explained by mechanisms other than the spinal processing of proprioceptive information. Studies reviewed indicate that changes in the ability to tolerate stretch and/or the vis‐coelastic properties of the stretched muscle, induced by PNF procedures, are possible mechanisms. 相似文献
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The purpose of the present study was to determine whether there is a sex difference in limb muscle cross-sectional area by comparing upper- and lower-body limb fat-free cross-sectional areas (FFCSAs) adjusted for differences in fat-free weight (FFW), in male and female athletes with similar histories of upper-body physical conditioning and in non-athletes. Limb FFCSAs were calculated from circumferences corrected for subcutaneous fat thickness and FFW was estimated from body density measured by underwater weighing in 24 male and 25 female swimmers and 23 male and 25 female non-athletes, 15 to 28 years of age. The male swimmers had 32% larger FFWs and 49% larger upper-arm, similar forearm and 23% larger thigh FFCSAs compared to the female swimmers. The male non-athletes had 34% larger FFWs, 61% larger upper-arms, 54% larger forearms and 35% larger thighs than female non-athletes. To adjust for differences in body size, analysis of covariance was performed on the FFCSAs using FFW as the covariate. For the swimmers there were no significant differences (P greater than 0.05) in the adjusted FFCSAs. For the non-athletes, males had significantly larger adjusted upper-arm and forearm FFCSAs than the females but thigh FFCSAs were not significantly different (P greater than 0.05). These results suggest that sex differences in muscle area of the arms, may be partially attributed to long-term activity differences between sexes. Possible long-term differences in activity between sexes should be considered in comparisons of functional or performance measures between sexes. 相似文献
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Optimal duration of static stretching exercises for improvement of coxo-femoral flexibility 总被引：1，自引：0，他引：1
The purpose of this study was to determine the effect of different durations of static stretching exercises on coxo-femoral (hip) flexibility. The experimental group, consisting of 20 sedentary women (20-30 years of age), participated in an exercise programme of static stretching exercises with emphasis on the hamstring muscles. The programme lasted for 10 weeks and consisted of two 50-min sessions per week. A control group of 15 sedentary women did not participate in the programme. Hip flexibility was determined before, during and at the end of the programme by means of a goniometric measuring technique developed by us and described elsewhere. Three sub-groups were formed, each following the same programme except that the duration of the static stretch differed (group 1, 10 s; group 2, 20 s; group 3, 30 s). The ANOVA tests showed that for all groups - the control group excepted - the hip flexibility had improved significantly after 10 weeks (P less than 0.05). No significant differences in hip flexibility were noted between the three subgroups at the end of the programme. This finding suggests that a duration of 10 s static stretching is sufficient for improving coxo-femoral flexibility. 相似文献
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傅振磊 《西安体育学院学报》2011,28(5)
在农村体育研究领域对农村体育认识存在较多争议,为使农村体育更加明确、统一,运用文献资料方法与逻辑分析方法对农村体育问题作进一步探索.结果显示:农村体育是指在处于部分连接、未连接状态的乡级地域和村级地域以及常住人口在3 000人以下或3 000人以上非独立的各类特殊区域内的群众体育和竞技体育. 相似文献