不同运动方式对大鼠急性拉伤修复过程中骨骼肌材料力学指标的影响

目的:分析研究不同运动方式对骨骼肌拉伤愈合过程的影响,为骨骼肌拉伤的运动康复疗法提供实验支持。方法:152只成年雌性SD大鼠随机分为空白对照组(BC组,n=8)、即刻组(IM组,n=8)、第1周组(1W组,n=8)、自然愈合组(NC组,n=32)、向心运动组(CE组,n=32)、离心运动组(EE组,n=32)和组合组(CO组,n=32)。除BC组外,其它各组造成腓肠肌急性拉伤模型,1周后,CE组、EE组、CO组分别进行为期4周的向心、离心和向心离心相结合的训练。IM组在造模即刻,1W组在造模后7天,BC在造模后18天取材;其余各组分别在造模后第14、21、28、35天4个时间点取材,每次随机选择8只,检测大鼠腓肠肌极限应力、极限应变率和杨氏模量。结果:向心运动训练能加快拉伤骨骼肌极限应力、极限应变率、杨氏模量的恢复。离心运动能加快拉伤骨骼肌极限应力恢复,但延缓了拉伤骨骼肌极限应变率和杨氏模量的恢复。向心和离心相结合的运动能加快拉伤骨骼肌极限应变率、极限应力和杨氏模量的恢复,组合组极限应变率和杨氏模量的恢复比离心组快,比向心组慢。结论:不同运动方式对急性拉伤后修复过程中骨骼肌材料力学性质的影响不同。向心、离心以及向心离心相结合的训练均能促进拉伤骨骼肌极限应变的恢复;向心和向心离心相结合训练能促进拉伤骨骼肌极限应变率的恢复;离心运动能加快拉伤骨骼肌极限应力的恢复,但延缓了拉伤骨骼肌极限应变率和杨氏模量的恢复,在增加骨骼肌强度的同时降低了其弹性。     

中药对大鼠急性骨骼肌拉伤后骨骼肌α-actinmRNA表达的影响

本研究建立了急性骨骼肌拉伤的动物实验模型 ,观察了不同治疗措施对拉伤后动物骨骼肌α -actinmRNA表达的影响。结果表明 :(1)急性拉伤后即刻 ,动物骨骼肌α-actinmRNA表达量显著增高 ,伤后第 1天、第 2天保持显著性高水平 ,至第 5天恢复至正常水平 ,但第 14天又显著增高 ;(2 )舒筋活血类中药抑制骨骼肌拉伤后α -actinmRNA表达的第 2次升高。研究提示 ,舒筋活血类中药能更有效地促进急性骨骼肌拉伤后α -actinmRNA表达的恢复。     

利用碱性成纤维细胞生长因子包裹的磁性纳米粒对大鼠急性骨骼肌钝挫伤后肌肉收缩力与松弛特性恢复的影响研究

目的:研究碱性成纤维细胞生长因子(bFGF)包裹的磁性纳米粒对大鼠急性骨骼肌钝挫伤后肌肉收缩力与松弛特性恢复的影响。方法:通过免疫化学偶联技术,制备重组bFGF包裹的磁性纳米粒。将雄性Wistar大鼠随机分为自然愈合组、生理盐水组、小牛血清白蛋白(BSA)包裹磁性纳米粒组、bFGF包裹磁性纳米粒组和bFGF直接注射组,采用重物下落装置建立大鼠急性骨骼肌钝挫伤模型,按上述分组方式分别于损伤部位皮下注射药物或不作处理,在外加磁场的牵引下靶向聚焦至损伤部位。在损伤后第2、10、17、24和30天分别取样,测定和计算肌肉收缩力和应力松弛。结果:磁纳米化的bFGF对大鼠腓肠肌钝挫伤后第17、24天的收缩力有明显提高作用;在损伤后第2天,磁纳米化的bFGF即能使应力松弛恢复接近正常肌肉水平;与bFGF直接注射组相比,bFGF包裹磁性纳米粒对损伤肌肉收缩力的提高更明显(P<0.05,第17天)。结论:磁纳米化的bFGF比直接注射bFGF能明显改善大鼠急性骨骼肌钝挫伤后肌肉收缩应力和恢复应力衰减。     

磁共振成像与超声检查在网球腿诊断中的价值对比研究

目的:探讨磁共振成像(MRI)与超声检查在网球腿诊断中的价值。方法:对32例临床诊断为网球腿病人行MRI与超声检查,比较2种影像学检查方法对病变的检出能力。结果:32例病人均为单腿受伤,MRI显示小腿三头肌拉伤20例,小腿三头肌撕裂8例,腓肠肌与比目鱼肌间积液24例,腓肠肌与比目鱼肌间筋膜损伤17例,跖肌腱断裂1例;超声显示小腿三头肌拉伤7例,小腿三头肌撕裂16例,腓肠肌与比目鱼肌间积液24例,腓肠肌与比目鱼肌间筋膜损伤18例,跖肌腱断裂3例。对于小腿三头肌拉伤,MRI较超声更敏感;对于小腿三头肌撕裂,超声较MRI更敏感;对于腓肠肌与比目鱼肌间积液及肌间筋膜损伤,两种检查方法的差异无统计学意义。结论:对于临床怀疑网球腿的病人,超声检查可作为首选,对于小腿三头肌拉伤的病人MRI可作为补充检查。     

枸杞汁对男性大学生递增负荷运动期间血睾酮及皮质醇水平的影响

目的:通过观察递增负荷运动期间补充枸杞汁对男性大学生血睾酮和皮质醇水平的影响,探讨补充枸杞汁预防运动性低血睾酮的效果。方法:28名健康男性大学生分为对照组(16人)和实验组(12人),进行为期32天、4个阶段的递增负荷跑步运动,实验期间实验组每人每天睡前饮用100 ml枸杞汁,递增负荷运动结束后又将对照组平均分为自然恢复组和枸杞汁恢复组(每天睡前饮用100 ml枸杞汁),持续8天。分别在实验前、每阶段最后一次运动次日晨和恢复期间第9天晨采集受试者肘静脉血测试睾酮、皮质醇,并计算睾酮/皮质醇比值(T/C)。结果:与对照组比较,实验组血清睾酮浓度在第3、4阶段均显著升高(P<0.05),而血清皮质醇浓度则在第4阶段显著降低(P<0.05),T/C在第3、4阶段末显著增大(P<0.05)。此外,枸杞汁恢复组于恢复期第9天血清睾酮浓度显著高于自然恢复组(P<0.05)。结论:补充枸杞汁对预防运动性低血睾酮有一定的效果,可加快运动后血睾酮水平的恢复。     

两种缺氧刺激对大学生红细胞生成素及有氧能力的影响

目的:探讨缺氧刺激对血清红细胞生成素(EPO)和转铁蛋白受体(sTfR)的影响,观察在低氧刺激环境下血液EPO分泌和血清sTfR浓度的变化规律.方法:受试者为20名身体健康的男性大学生,随机分为3组:间歇吸低氧组(n=7)、模拟高住组(n=5)和对照组(n=8).间歇吸低氧组每天30分钟吸低氧,模拟高住组每天8小时低氧环境睡眠.所有受试者在实验期均从事相同的体育技术课和理论课学习及相同的生活作息,全部实验共包括4周试验期和2周恢复期.结果:(1)对照组血清EPO浓度在实验前、中和恢复期均无明显变化.间歇吸低氧组血清EPO浓度在实验第3天、第17天、第22天,模拟高住组血清EPO浓度在实验第15天、第17天、第22天、第24天及恢复期均显著高于实验前(P＜0.05),(2)间歇吸低氧组血清sTfR浓度在实验第3天、第10天、第17天及恢复期结束均显著高于实验前(P＜0.05),而模拟高住组和对照组血清sTfR浓度在实验期和恢复期均未发生明显变化.(3)实验后间歇吸低氧组受试者VO2max与实验前比较明显增加(P＜0.05).(4)除对照组外,实验后间歇吸低氧组、模拟高住组在定量负荷运动中的心率、血乳酸与实验前相比显著下降(P＜0.05).结论:血清EPO、sTfR浓度的变化受不同低氧浓度刺激时间和方式的影响,间歇吸低氧与运动刺激相结合可增加VO2max.     

头低位卧床期间体育锻炼30d对下肢肌肉的影响

目的:通过观察和比较30 d头低位卧床期间不同体育锻炼方式对下肢肌肉的影响,以进一步明确体育锻炼对失重后下肢肌肉萎缩的对抗效果。方法:15名男性健康被试者,随机分为对照组、下肢肌力训练组和自行车功量计训练组。实验期间测量小腿周径、小腿截面积、腓肠肌肌电平均振幅的变化。结果:与卧床前相比,对照组小腿周径随卧床时间延长显著减小(P<0.01);下肢肌力训练组在卧床第18～30天以及起床后的小腿周径显著减小(P<0.01);自行车功量计训练组在卧床第22～30天及起床后显著减小(P<0.01)。与卧床前相比,卧床第30天和起床后1周时3组的小腿截面积均显著减小(P<0.05)。与卧床前相比,对照组肌电振幅在第1和22天显著降低(P<0.05),下肢肌力训练组的肌电振幅在卧床第7、22、26和30天显著降低(P<0.05),自行车功量计组在卧床第7、10、22和30天显著降低(P<0.05)。结论:30 d头低位卧床可引起严重的肌肉萎缩。下肢肌力训练和自行车功量计训练对防止模拟失重所致肌肉萎缩,促进肌肉恢复有一定的作用。     

放射复合伤小鼠骨髓基质细胞体外培养生长的特点

用Dexter法检测经5.0 Gy γ射线照射致15% Ⅲ度烧伤和放射复合伤小鼠伤后不同时间骨髓基质细胞集落形成能力.结果表明,单放组和复合伤组于伤后各时相点均显著低于正常组和单烧组;单烧组除伤后第3天低于正常组外(P<0.05),至伤后第14天与正常组比较,差异无显著性意义(P>0.05).伤后3、7天的单放组骨髓基质细胞经21天培养后呈小团片状生长,培养至第28天仍未长满培养皿底.提示:单放组和复合伤组骨髓基质细胞受损后恢复缓慢;放射复合伤对骨髓基质细胞的损伤特点是以放射损伤为主.     

舒筋活血类中药对大鼠急性骨骼肌拉伤后血清CK、LDH活性的影响

为观察舒筋活血类中药对急性运动性肌损伤的疗效 ,测定了急性骨骼肌拉伤大鼠应用舒筋活血类中药治疗后血清CK、LDH活性的变化。结果表明 :(1)舒筋活血类中药治疗组动物血清CK、LDH活性比自然恢复组和西药治疗组恢复得快 ;(2 )舒筋活血类中药抑制骨骼肌拉伤后血清CK、LDH活性的第 2次升高。结果提示舒筋活血类中药能更有效地促进骨骼肌急性拉伤后血清酶活性的正常恢复。     

地震伤并发气性坏疽2例的救治体会

<正>病例1:女,15岁。因地震时教室倒塌,未能逃脱,蜷缩于狭窄空间,左膝关节极度屈曲,24 h后被他人救出送入当地医院。当日出现左小腿明显肿胀,遂行左小腿外侧切开减张,术后出现高热,左小腿仍肿胀明显,于伤后第5天再次行左小腿内侧减张及部分坏死肌肉清除,伤后第6天     

骨骼肌离心收缩运动致延迟性肌肉损伤的生物力学研究

研究离心运动后快慢骨骼肌生物力学性质的变化,以及与延迟性骨骼肌损伤的关系。结果发现大鼠经间歇性离心运动训练后,快慢骨骼肌被动拉伸时的极限强度、极限应变、弹性模量、能量吸收等材料力学性质,在运动后随时间的延长而逐渐显著增强,出现超量恢复。结果提示：可能正是由于离心运动后骨骼肌材料力学性质的变化,离心运动有效地阻止或减轻了延迟性肌肉酸痛的发生。     

中医消除运动性肌肉疲劳动物实验研究——外用、内服中药对两周离心训练后兔骨骼肌形态学、组织学和细胞学影响

72只家兔分成对照组、内服中药组和外用中药组 ,分别进行连续 3、7、14天小腿前群肌肉离心训练 (第 2周增加负荷 ) ,测定肌肉硬度、踝关节松弛角度、胫前肌常规组织学、肌肉细胞凋亡、肌肉骨架蛋白desmin以及透射电镜肌节长度。结果显示 :离心运动后产生的适应可使骨骼肌承受更大的离心负荷 ,并在一定时间内不影响肌肉的恢复 ,也不对肌肉造成进一步的损伤。实验用的九九疲王口服液和按摩乳对上述形态学、组织学指标的恢复有明显作用 ,大强度连续离心训练后肌肉细胞凋亡、肌肉骨架蛋白desmin染色面积都有明显改变 ,其机制尚需进一步研究。     

Unstable rocker shoes promote recovery from marathon‐induced muscle damage in novice runners

We recently reported that wearing unstable rocker shoes (Masai Barefoot Technology: MBT ) may enhance recovery from marathon race‐induced fatigue. However, this earlier study only utilized a questionnaire. In this study, we evaluated MBT utilizing objective physiological measures of recovery from marathon‐induced muscle damages. Twenty‐five university student novice runners were divided into two groups. After running a full marathon, one group wore MBT shoes (MBT group), and the control group (CON ) wore ordinary shoes daily for 1 week following the race. We measured maximal isometric joint torque, muscle hardness (real time tissue elastography of the strain ratio) in the lower limb muscles before, immediately after, and 1, 3, and 8 days following the marathon. We calculated the magnitude of recovery by observing the difference in each value between the first measurement and the latter measurements. Results showed that isometric torques in knee flexion recovered at the first day after the race in the MBT group while it did not recover even at the eighth day in the CON group. Muscle hardness in the gastrocnemius and vastus lateralis showed enhanced recovery in the MBT group in comparison with the CON group. Also for muscle hardness in the tibialis anterior and biceps femoris, the timing of recovery was delayed in the CON group. In conclusion, wearing MBT shoes enhanced recovery in lower leg and thigh muscles from muscle damage induced by marathon running.     

The effects of 12 weeks of functional strength training on muscle strength,volume and activity upon exposure to elevated Gz forces in high-performance aircraft personnel

Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1) the volume and strength of the neck and shoulder muscles and 2) muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel.Methods:Eighteen participants underwent 12 weeks of functional strength training (n=12) or the control protocol(n=6) without additional strength training.Pre-and post-intervention tests included evaluations of isometric strength of the head extensor muscles,flexion,and lateral flexion and rotation,as well as magnetic resonance imaging (MRI)to measure the volume of the m.stemocleidomastoideus,m.trapezius,and deep neck muscles.Furthermore,during a long-arm centrifuge (+1.4 and +3Gz) protocol,the muscular activity levels of the m.sternocleidomastoideus,m.trapezius and m.erector spinae muscles were assessed without a flight helmet,with a helmet,and with a helmet and night vision goggles.Each participant's perception of muscular strain was noted immediately after the long-arm centrifuge protocol.Results:The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group (P＜0.05).Relative muscle activity (％MVC) with a helmet decreased after the intervention in the training but not the control group (P=0.01).Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group (P＜0.01).The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups.Conclusions:Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge.     

低氧训练对AMPKα2三种基因状态鼠骨骼肌HIF-1α mRNA表达的影响

目的:探讨低氧耐力训练对AMPKα2基因敲除(KO)、高表达转基因(OE)及野生型(WT)小鼠骨骼肌HIF-1α mRNA表达的影响。方法:WT、KO及OE鼠各30只,分别随机分为常氧对照组、低氧暴露组和低氧训练组。常氧对照组在常氧状态下饲养14天;低氧暴露组在低氧环境(模拟海拔4000米高度,氧浓度约12.3%)下饲养14天;低氧训练组在与低氧暴露组相同的低氧环境下饲养并连续14天进行跑台训练(12 m/min,1 h/day)。14天后断食12 h取材,测定小鼠骨骼肌AMPKα2蛋白和HIF-1α mRNA表达。结果:(1)OE和WT鼠低氧暴露组、低氧训练组骨骼肌AMPKα2蛋白表达与常氧对照组相比均无显著性差异,KO鼠骨骼肌无AMPKα2蛋白表达。(2)OE鼠、KO鼠和WT鼠低氧训练组骨骼肌HIF-1α mRNA表达量与低氧暴露组相比显著增加。(3)低氧训练下,OE鼠骨骼肌HIF-1α mRNA表达量与WT鼠相比有显著性差异。结论:低氧训练中AMPKα2对骨骼肌HIF-1α mRNA表达起重要作用,但并非HIF-1α表达的必要条件。     

Muscle oxygenation and fascicle length during passive muscle stretching in ballet-trained subjects

Muscle stretching transiently decreases muscle-blood flow corresponding to a muscle extension. It may disturb a balance between muscular oxygen demand and oxygen supply to muscles and reduce muscle oxygenation. However, muscle-stretching training may improve blood circulatory condition, resulting in the maintained muscle oxygenation during muscle stretching. The aim of this study was to investigate changes in muscle-blood volume (tHb) and tissue oxygenation index (TOI) during muscle stretching determined by using near-infrared spectroscopy (NIRS) in ballet-trained (BT) and untrained (C) subjects. 11 BT women who regularly perform muscle stretching and 11 C women participated in this study. Fascicle lengths, tHb and TOI in the tibialis anterior muscle were measured during passive plantar flexion from ankle joint angles of 120° (baseline) to 140°, 160°, the maximal comfortable position without pain (CP), and the maximal position (MP). At 160°, the % fascicle-length change from baseline was significantly lower in the BT than the C group, however, for the changes in tHb and TOI the significant interaction effect between the 2 groups was not detected. On the other hand, although the increases in the fascicle length from baseline to CP and MP were greater in BT than C, the tHb and TOI reductions were comparable between groups. We concluded that it appears that BT can extend their muscles without excessive reduction in muscle-blood volume and muscle oxygenation at relatively same but absolutely greater muscle-stretching levels than C. The attenuation in these indices during high-level muscle stretching may be associated with the repetitive muscle stretching of long-term ballet training.     

Resistance exercise training in patients with heart failure

The utility, safety and physiological adaptations of resistance exercise training in patients with chronic heart failure (CHF) are reviewed and recommendations based on current research are presented. Patients with CHF have a poor clinical status and impaired exercise capacity due to both cardiac limitations and peripheral maladaptations of the skeletal musculature. Because muscle atrophy has been demonstrated to be a hallmark of CHF, the main principle of exercise programmes in such patients is to train the peripheral muscles effectively without producing great cardiovascular stress. For this reason, new modes of training as well as new training methods have been applied. Dynamic resistance training, based on the principles of interval training, has recently been established as a safe and effective mode of exercise in patients with CHF. Patients perform dynamic strength exercises slowly, on specific machines at an intensity usually in the range of 50-60% of one repetition maximum; work phases are of short duration (< or =60 seconds) and should be followed by an adequate recovery period (work/recovery ratio >1 : 2). Patients with a low cardiac reserve can use small free weights (0.5, 1 or 3 kg), elastic bands with 8-10 repetitions, or they can perform resistance exercises in a segmental fashion. Based on recent scientific evidence, the application of specific resistance exercise programmes is safe and induces significant histochemical, metabolic and functional adaptations in skeletal muscles, contributing to the treatment of muscle weakness and specific myopathy occurring in the majority of CHF patients. Increased exercise tolerance and peak oxygen consumption (V-dotO(2peak)), changes in muscle composition, increases in muscle mass, alterations in skeletal muscle metabolism, improvement in muscular strength and endurance have also been reported in the literature after resistance exercise alone or in combination with aerobic exercise. According to new scientific evidence, appropriate dynamic resistance exercise should be recommended as a safe and effective alternative training mode (supplementary to conventional aerobic exercise) in order to counteract peripheral maladaptation and improve muscle strength, which is necessary for recreational and daily living activities, and thus quality of life, of patients with stable, CHF.     

Trampoline exercise vs. strength training to reduce neck strain in fighter pilots

INTRODUCTION: Fighter pilots' muscular strength and endurance are subjected to very high demands. Pilots' fatigued muscles are at higher risk for injuries. The purpose of this study was to compare the effects of two different training methods in reducing muscular loading during in-flight and cervical loading testing (CLT). METHODS: There were 16 volunteer Finnish Air Force cadets who were divided into 2 groups: a strength training group (STG) and a trampoline training group (TTG). During the 6-wk training period, the STG performed dynamic flexion and extension and isometric rotation exercises, and the TTG performed trampoline bouncing exercises. During in-flight and CLT, muscle strain from the sternocleidomastoid, cervical erector spinae, trapezius, and thoracic erector spinae muscles was recorded with EMG. RESULTS: In-flight muscle strain in the STG after the training period decreased in the sternocleidomastoid 50%, cervical erector spinae 3%, trapezius 4%, and thoracic erector spinae 8%. In the TTG, the decrease was 41%, 30%, 20%, and 6%, respectively. In CLT, the results were similar. After a 3-mo follow-up period with intensive high +Gz flying, EMG during CLT was still lower than in baseline measurements. CONCLUSION: Both training methods were found to be effective in reducing muscle strain during in-flight and CLT, especially in the cervical muscles. There was no statistically significant difference between the training groups. Introduced exercises expand muscles' capacities in different ways and the authors recommend both strength and trampoline training programs to be included in fighter pilots' physical education programs.     

Muscle fatigue caused by repeated aerial combat maneuvering exercises.

BACKGROUND: Little is known about the development of in-flight muscular fatigue during repeated flights. HYPOTHESIS: This study was conducted to evaluate muscular fatigue in different upper body and neck muscles during repeated aerial combat maneuvering exercises. METHODS: Six pilots volunteered as test subjects. They performed one-to-one dog fight exercise three times (1 pilot, four times) in one day. During the flights, the pilots' electromyographic activity (EMG) was measured from the abdomen, back, neck and lateral neck. The mean muscular strain for each muscle was calculated. Before the first flight and after each flight, the maximal isometric strength of each muscle was measured. RESULTS: The results showed that maximal isometric strength between the first and last measurement decreased in the back, neck (p < 0.05) and lateral neck muscles. While the G-stress remained the same, the muscular strain during exercises increased in every muscle, but was significant only in neck and lateral neck (p < 0.05-0.01). Due to these changes, the fatigue index in the neck and lateral neck muscles was 2.0-2.1, and 1.3-1.4 (1.0 = no fatigue) in the abdomen and back muscles. CONCLUSIONS: Repeated aerial combat maneuvering exercises caused fatigue in every muscle studied. The fatigue was greater in the neck area, which may increase the risk for neck injuries, and may reduce mission effectiveness. The fighter pilots' muscular strength and endurance in the neck area are subjected to very high demands, especially if exercises are repeated several times. The recovery of the neck muscles from fatigue after repetitive exercises should receive special attention.