肌腱生物力学性能与运动训练

肌腱是运动系统中的重要结构,其生物力学性能在一定程度上影响着运动成绩和运动损伤的发生率。通过检索国内外相关文献,综述目前国内外有关运动训练对肌腱生物力学性能影响的研究。相对于骨和韧带等领域研究,肌腱领域研究不多且结果不尽相同,动物和人体的研究大都集中于跑步训练和力量训练,一些研究结果表明长期运动后肌腱的生物力学性能会发生一定的改变。运动训练后肌腱生物力学的改变和年龄、运动负荷、运动模式及肌腱部位等相关。     

骨质疏松症与衰老的关系

目的：衰老是致骨质疏松的一个重要因素。探讨衰老引起骨质疏松的机制，对于骨质疏松的预防和治疗是很有必要的。资料来源：应用计算机检索Medline 1990—01／2004—07的文章，检索词“osteoporosis，pathogenesis，aging”，并限定语言种类为英语。同时计算机检索万方数据资源系统与中国期刊全文数据库1994—01／2004—06的文章，限定文章语言种类为中文，检索词“骨质疏松，发病机制，衰老”。资料选择：对资料进行初审，选取实验包括实验组和对照组的文献，筛除明显不随机实验的研究，对剩余的文献开始查找全文，进一步判断为随机对照实验。纳入标准为①随机对照实验，采用单盲，双盲或非盲法。②实验包含平行对照组。排除标准：重复性实验研究。资料提炼：共收集到20篇关于老年性骨质疏松症发病机制的随机对照实验文章，17个实验符合纳入标准。排除的3篇实验均为重复的同一研究。资料综合：17个实验包括老年性骨质疏松症与成骨细胞、破骨细胞功能、晚期糖基化终产物、激素、生长因子、营养、运动的关系以及中医对老年性骨质疏松症发病机制研究，分别对各实验给予评价。结论：骨质疏松症是一个由基因、激素和环境等多种因素相互作用的多病因疾病，衰老是引起骨质疏松的一个重要因素。与年龄相关的骨量丢失不仅仅是由于体内激素的缺乏所引起，而且与生长因子的缺乏、营养不良、运动减少等有关。     

运动性肌腱损伤同种异体移植和外科修复的生物力学特征

背景:为了提高肌腱损伤后的缝合修复强度、尽早开始主被锻炼、防止肌腱粘连,研究者们在不断地寻找更牢固的缝合方法。大于3cm的肌腱缺损.不能直接缝合,目前主要依靠自体、异体肌腱移植修复。目的:总结同种异体肌腱移植和外科修复运动性肌腱损伤涉及的生物力学研究现状。方法:应用计算机检索PubMed数据库及中国期刊网全文数据库1994-01/2011-10有关肌腱损伤的外科修复和同种异体肌腱移植修复的生物力学方面的文章,英文检索词为"tendon,biomechanical study,repair,suture,allogenetic tendon",中文检索词为"肌腱,生物力学,同种异体移植,缝合"。排除重复性及非中英文语种研究,共保留34篇文献进行综述。结果与结论:对肌腱吻合方法进行生物力学测量,能了解哪种方法更能满足早期功能锻炼的需要,更能有效防止肌腱再断裂和吻合处间隙形成,以便在术后早期功能锻炼时有更大的安全性。深低温冷冻化和玻璃化保存同种异体肌腱移植在生物力学方面的表现与自体肌腱移植结果基本相同,可替代自体肌腱应用于移植修复肌腱缺损。     

肌腱肥大与运动训练

背景:肌腱形态结构和肌腱的生物力学性能相关,影响着运动成绩和运动损伤的发生率.目的:综述和分析了目前有关肌腱运动性肥大的相关研究,以期为有关肌腱运动适应性研究提供参考,需要指出的是文中肌腱所指的为游离无症状肌腱.方法:检索中国期刊全文数据库和PubMed数据库1980/2010收录的有关运动训练后肌腱形态结构变化及肌腱细胞外基质胶原代谢方面的文献.结果与结论:对纳入的37篇文献进行分析.长期运动后肌腱会产生区域性肥大,运动训练后肌腱是否肥大可能主要和年龄、运动负荷有关,从生长期就开始进行运动可能更容易产生肌腱区域性肥大,而且可能需要较大的运动强度和较长的持续时间.运动训练后肌腱产生区域肥大可能与运动训练后胶原更新率增加,从而导致胶原原纤维数量、直径变化有关.     

肌腱移植材料与组织工程化肌腱移植技术

目的:就近年来国内外肌腱移植材料的研究进展,对组织工程化肌腱移植技术取得的成果进行总结。资料来源:应用计算机检索Medline1980-01/2005-01相关肌腱移植材料与组织工程化肌腱移植技术的文献,检索词“tendon transplant,tissue engineer,progress”,并限定文献语言种类为English。同时计算机检索CBM1990-01/2005-01相关肌腱移植材料与组织工程化肌腱移植技术方面的文献,检索词为“肌腱移植,组织工程,综述文献”,并限定语言种类为中文。资料选择:对资料进行初审,选取包括肌腱移植材料与组织工程化肌腱移植技术的文献,开始查找全文。纳入标准:①肌腱移植材料。②组织工程化肌腱移植技术。排除标准:综述文献,重复研究,Meta分析类文章。资料提炼:共收集到45篇关于肌腱移植材料与组织工程化肌腱移植技术的文献,纳入30篇符合标准的文献。资料综合:用于肌腱移植的材料主要有以下几类:自体肌腱、同种异体肌腱、人工肌腱和组织工程化肌腱。近年来在异体肌腱移植方面取得了较成熟的经验。20世纪80年代后期组织工程技术的建立和发展,为肌腱组织缺损的修复又提供了一条新的思路和途径。组织工程化肌腱的研究目的是将体外预制的肌腱回植入体内的肌腱缺损处以恢复关节的功能。目前,研究者正致力于研究同时集两类生物材料优点的细胞支架,与肌腱细胞联合体外培养,使之可以成为一种永久性的有生命活性的组织工程化肌腱。结论:肌腱移植的材料主要有自体肌腱、同种异体肌腱、人工肌腱和组织工程化肌腱等。种子细胞、细胞外基质材料应用的深入研究必将推动组织工程化肌腱移植技术的进一步发展。     

骨质疏松症与衰老的关系

目的:衰老是致骨质疏松的一个重要因素。探讨衰老引起骨质疏松的机制,对于骨质疏松的预防和治疗是很有必要的。资料来源:应用计算机检索Medline1990-01/2004-07的文章,检索词“osteoporosis,pathogenesis,aging”,并限定语言种类为英语。同时计算机检索万方数据资源系统与中国期刊全文数据库1994-01/2004-06的文章,限定文章语言种类为中文,检索词“骨质疏松,发病机制,衰老”。资料选择:对资料进行初审,选取实验包括实验组和对照组的文献,筛除明显不随机实验的研究,对剩余的文献开始查找全文,进一步判断为随机对照实验。纳入标准为①随机对照实验,采用单盲,双盲或非盲法。②实验包含平行对照组。排除标准:重复性实验研究。资料提炼:共收集到20篇关于老年性骨质疏松症发病机制的随机对照实验文章,17个实验符合纳入标准。排除的3篇实验均为重复的同一研究。资料综合:17个实验包括老年性骨质疏松症与成骨细胞、破骨细胞功能、晚期糖基化终产物、激素、生长因子、营养、运动的关系以及中医对老年性骨质疏松症发病机制研究,分别对各实验给予评价。结论:骨质疏松症是一个由基因、激素和环境等多种因素相互作用的多病因疾病,衰老是引起骨质疏松的一个重要因素。与年龄相关的骨量丢失不仅仅是由于体内激素的缺乏     

生物材料预防肌腱运动损伤后粘连及促愈合作用

背景:肌腱损伤后常见的并发症是肌腱粘连,其防治一直是医学界普遍关注的问题.目的:综述生物材料预防肌腱损运动伤后粘连及促愈合作用.方法:以生物材料,肌腱损伤,预防粘连,修复为中文关键词,biologicalmaterial,tendon injury,prevent antistick,repair为英文关键词,采用计算机检索1980-01/2010-12 相关文章.纳入与生物材料与组织工程骨缺损修复相关的文章;排除重复研究或Meta 分析类文章.结果与结论:肌腱损伤后的愈合包括内源性愈合、外源性愈合两种形式.防止肌腱粘连的理想途径,是通过改善肌腱的营养状况和周围环境,来促进内源性愈合,抑制或减轻外源性愈合.文章就目前常用的几种生物材料预防肌腱粘连的作用机制及特点进行了探讨,以便更好地发挥其预防肌腱粘连的作用.     

生物材料预防肌腱运动损伤后粘连及促愈合作用

背景：肌腱损伤后常见的并发症是肌腱粘连,其防治一直是医学界普遍关注的问题。目的：综述生物材料预防肌腱损运动伤后粘连及促愈合作用。方法：以＂生物材料,肌腱损伤,预防粘连,修复＂为中文关键词,＂biologicalmaterial,tendon injury,prevent antistick,repair＂为英文关键词,采用计算机检索1980-01/2010-12相关文章。纳入与生物材料与组织工程骨缺损修复相关的文章;排除重复研究或Meta分析类文章。结果与结论：肌腱损伤后的愈合包括内源性愈合、外源性愈合两种形式。防止肌腱粘连的理想途径,是通过改善肌腱的营养状况和周围环境,来促进内源性愈合,抑制或减轻外源性愈合。文章就目前常用的几种生物材料预防肌腱粘连的作用机制及特点进行了探讨,以便更好地发挥其预防肌腱粘连的作用。     

过度运动对肱二头肌长头肌腱组织学及生物力学特性的影响

目的探讨过度运动和肱二头肌长头肌腱炎的关系及在肩关节疾病中的地位。方法用随机分组的方法将24只SpragueDawley(SD)大鼠随机分为两组,分别进行4周和8周的过度运动,建立大鼠肩关节过度异常运动模型,采用组织学方法和生物力学方法研究肌腱组织及生物力学特性的改变。结果过度运动的肱二头肌长头肌腱和对照组比较,组织学及生物力学特性发生了显著的改变。正常大鼠肱二头肌长头肌腱无纤维软骨样结构。过度运动后,肌腱某些部位胶原纤维发生变性,部分断裂,着色变浅,纤维细胞数量在运动4周后和8周后减少。细胞由梭型变为圆形,部分向软骨细胞分化,形成纤维软骨样结构。生物力学实验中发现肌腱所能承受的最大载荷和最大应力均有显著的降低(P＜0.01)。肌腱最易发生断裂的部位和肌腱发生变性的部位一致。结论肩关节的过度运动可以导致肱二头肌腱变性,从而诱发肩关节疾病。     

人工生物材料修复肌腱急性损伤及预防粘连

背景：肌腱损伤后的治疗措施经历了传统物理疗法、药物疗法以及现代组织工程学人工韧带的重建等漫长过程。目的：综述人工生物材料干预治疗肌腱粘连的措施,并探讨肌腱治疗过程中粘连的发生机制。方法：应用计算机检索万方、维普数据库和PubMed数据库中1990-01/2011-04与肌腱康复措施及材料学相关的文章,在标题和摘要中以＂肌腱,治疗,材料,粘连＂或＂tendon,treatment,materials,adhesion＂为检索词进行检索。选择文章内容与肌腱治疗材料学相关,同一领域文献则选择近期发表或发表在权威杂志文章。初检得到287篇文献,根据纳入标准选择21篇文章进行综述。结果与结论：人工韧带的重建与再生为严重的肌腱治疗与康复提供了可能和保障,但理想人工韧带材料的选择和研制成为治疗的关键,合成材料可以避免单一材料性能的不足,为材料的研制提供了广阔的发展空间,目前,基因治疗技术的发展也为肌腱组织工程技术提供了崭新的研究方向。另外,肌腱在治疗康复过程中往往发生粘连,严重影响着治疗效果,肌腱粘连与肌腱愈合的特点及其生理和病理有重要关系,采用生物材料作为预防粘连隔离物具有广阔的发展前景。     

高强度耐力运动过程中肌腱结构及力学性质的变化

目的:观察高强度耐力性训练对肌腱结构、力学性质的影响。方法:实验于2002-03/07在解放军第一五○医院全军军事医学研究所完成,健康10个月龄豚鼠70只,随机数字法分为实验组及对照组,对照组10只,实验组60只,实验组中再次随机数字法分为6组,分别于实验第1～6周投入运动训练,实验动物于特制跑台内进行运动训练,跑道速度25m/min,坡度为0,时间1h,共计跑步1500m,训练6d/周,训练结束所有动物一并取材,分别取双侧跟腱,左右分开,左侧跟腱行透射电镜观察超微结构,右侧跟腱在材料实验机上进行生物力学性质测试,根据肌腱的负荷-形变曲线测量屈服强度、应变、能量吸收指标。结果:实验豚鼠70只均进入结果分析。①超微结构观察,运动实验过程中肌腱中胶原纤维束直径逐渐减小,第6周实验组中肌腱中大量纤细胶原纤维束平行密集排布,且第4周时发现沿胶原纤维束走行出现微小空虚区,纤维束连续性中断,提示肌腱中微损伤出现。②生物力学性质检测运动过程中肌腱屈服强度和能量吸收训练1周组高于对照组,训练4周组低于对照组,能量吸收随屈服强度相应变化,应变在训练过程中无明显变化,提示肌腱在短时间高强度训练过程中出现强度下降现象[屈服强度:对照组(86.438±5.505)kN,训练1周组(92.731±4.511)kN,训练4周组(82.218±5.234)kN;能量吸收:对照组(0.207±0.027)kJ,训练1周组(0.254±0.030)kJ,训练4周组(0.192±0.035)kJ,P<0.05]。结论:肌腱对运动训练可发生适应性改建,在此过程中伴随着疲劳性损伤发生。     

反复冻融处理同种异体移植兔跟腱组织学及生物力学变化

背景:近年来反复冻融处理技术作为一种同种异体肌腱的保存处理方法,主要原理是反复利用0～-60℃腱细胞最易损伤的冷冻温度,使得肌腱内细胞无活性,从而降低免疫原性.目的:拟观察反复冻融处理对同种异体移植兔跟腱组织学和生物力学的影响.设计、时间及地点:组织形态学及生物力学水平的对照动物实验,于2007-10/2008-02在北京大学运动医学研究所实验室完成.材料:选用17只成年健康新西兰大白兔.方法:无菌条件下取兔跟腱并带0.6 cm×0.4 cm跟骨骨块,按照组织库程序行60Co照射68 min,照射剂量为25 kGy.分为3组,-80 ℃冷冻,室温融解,反复冻融次数分别是1,3和10次,每组又抽取7条肌腱作生物力学测定,4条作组织学观察.主要观察指标:取肌腱行苏木精-伊红染色、胶原Van Gieson染色和透射电镜扫描,观察跟腱组织形态学改变,并进行跟腱拉伸实验以观察生物力学变化.结果:组织学观察发现,随着反复冻融次数的增加,腱束和胶原纤维捧列变得混乱直至断裂,细胞崩解,并且由于冰晶形成造成明显的腱束间裂隙.生物力学方面,与冻融1次组比较,冻融3,10次组的最大载荷、最大载荷能量及最大应力均显著降低(P<0.05),其他指标如弹性模量、能量密度也有下降但不明显.结论:反复冻融处理肌腱是一种有创的处理方法,正如组织学表现的可以引起细胞崩解、腱纤维紊乱甚至断裂等,最终会导致其生物力学水平的下降.     

Low-load behaviour of the patellar tendon graft and its relevance to the biomechanics of the reconstructed knee

BACKGROUND: Although the linear elastic (high-load) properties of patellar tendon graft used for anterior cruciate ligament (ACL) reconstruction are studied extensively, the low-load properties of the graft, associated with the toe region of its load-deformation curve, are largely neglected. The objectives of this study were to (i) determine the properties of the patellar tendon in the low-load region and compare to that of the intact ACL, (ii) assess the extent of variability in these properties and relate them to donor factors, and (iii) establish the theoretical importance of low-load properties to the function of the reconstructed knee. METHODS: The patellar tendons of 20 unpaired fresh frozen human knees (10 males and 10 females) were harvested. The central portions were trimmed, measured, and tested in tension to failure. The stress-strain curves were fitted with a bi-linear model and the graft properties were measured. FINDINGS: The low-load region modulus of elasticity, E 0, of the patellar tendon, ranged from 49 MPa to 276 MPa in males and 63 MPa to 279 MPa in females. The strain at which the graft transitions from its low-load region to its linear elastic region (epsilon* approximately 4.6%) is on average above the strain levels experienced by the ACL during daily activities (epsilon approximately 4%). Donor sex, height and body mass were found to significantly affect some of the mechanical properties of the low-load region. INTERPRETATION: The results suggest that the low-load region properties of the patellar tendon, not the linear elastic properties, govern the biomechanics of the tibiofemoral joint during the early healing period. Also, a wide variability of graft properties in the low-load region exists partly due to certain donor factors. Clinicians should be aware of the low-load region behaviour of the graft and its influence on time=0 behaviour of the reconstructed knee.     

Alterations in G-proteins and beta-adrenergic responsive adenylyl cyclase in rat urinary bladder during aging

Decreased response of bladder to beta-adrenergic stimulation with aging is related to decreased adenylyl cyclase activity and possibly to changes in guanine nucleotide regulatory protein (G-protein) content or function. G-protein content was quantified by Western blot analysis using antibodies to Gsalpha, Goalpha, and Gialpha in 21-day-old (weanling), 90-day-old (young adult), 6-month-old (adult), and 24-month-old (old) rat bladders. Gi/Go function in bladders with aging was measured by ADP-ribosylation with pertussis toxin. Content of Gsalpha, Goalpha, and Gialpha was lower in 90-day-old bladder than in 21-day-old bladder. Gsalpha content was similar in the 21-day-, 6-month-, and 24-month-old bladders. Gialpha content as well as pertussis toxin-catalyzed ADP-ribosylation was higher in 24-month-old bladders than in 21- and 90-day-old bladders. Pertussis toxin-catalyzed ADP-ribosylation of bladder membranes and treatment of bladder with protein kinase A inhibitors reversed the age-dependent decline in isoproterenol stimulation of adenylyl cyclase. Decreases in beta-adrenergic-induced relaxation response with age in rat bladder are due in part to increases in the content and functional activity of pertussis toxin-sensitive G-protein.     

Alterations in joint kinematics during walking following hamstring and patellar tendon anterior cruciate ligament reconstruction surgery

Background

Previous research has shown that patients with anterior cruciate ligament reconstruction have altered movement patterns in the reconstructed knee during walking. In the sagittal plane, graft specific changes in knee joint motion have been reported between hamstring and patellar tendon anterior cruciate ligament reconstruction grafts. This study examined the secondary planes of movement during walking in anterior cruciate ligament reconstructed knees to evaluate the influences of graft type (hamstring or patellar tendon) and control condition (control group or contralateral knee).

Methods

In 54 participants (18 patellar tendon graft, 18 hamstring graft and 18 controls) varus–valgus and internal–external rotation was measured during level walking in a gait laboratory at mean of 10 months after surgery. All patients had undergone primary unilateral anterior cruciate ligament reconstruction within 12 months of injury.

Findings

For internal–external rotation there was no difference between the graft types and both patient groups had reduced internal rotation (an external rotation offset) and reduced internal rotation range when compared to the control group and contralateral knee. For 31 of 36 patients, internal rotation values were less than the control group mean. The hamstring group had reduced varus rotation compared to both the patellar tendon and control groups, but not when compared to the contralateral knee.

Interpretation

The results show that there are differences in tibial rotation during walking in anterior cruciate ligament reconstructed knees compared to both the contralateral knee and uninjured control group. These kinematic alterations may relate to the high incidence of knee osteoarthritis observed in this population over time. Reduced varus in the hamstring group may relate to the graft harvest.     

Studies of biochemistry and clinical biochemistry. Studies at sample medical schools in 13 EU countries regarding biochemistry and clinical biochemistry teaching

The study summarizes the results obtained during personal visits to 53 medical schools in the 13 original EU countries during 2004--2006. Data from the Czech Republic is shown for comparison. The possibilities of acquiring information from the websites of the medical schools in the local language and English are assessed. The admission process to medical schools and the organization of studies of medicine, dentistry, and non-medical healthcare fields are briefly characterized. Significant attention is paid to the forms of education in biochemistry and clinical (bio)chemistry in the medical study field. The position of these subjects in the studies of dentistry and non-medical healthcare fields is also noted. In addition, the course of subject exams is described. The methods of funding and postgraduate studies at the medical schools are also briefly addressed.     

Shoulder anatomy and biomechanics

The evaluation of shoulder disorders is challenging because of anatomic and biomechanical complexities. The shoulder comprises three synovial joints and two movement interfaces. The following principles are important to establish an accurate anatomic diagnosis and to develop a treatment plan: (1) perform a careful history and physical examination; (2) determine whether or not the problem is mechanical; (3) for mechanical problems, establish pathophysiologic and mechanical diagnoses; and (4) use mechanical impairments as the basis for therapeutic interventions.     

Strain on the repaired supraspinatus tendon during manual traction and translational glide mobilization on the glenohumeral joint: a cadaveric biomechanics study

There has been no report on the mechanical effects of joint mobilization on rotator cuffs. The purpose of this study was to determine whether it is safe to use grade 3 joint mobilization techniques after rotator cuff repair. Nine fresh frozen cadaveric shoulders were used in this study. The strains on the artificially repaired supraspinatus tendon during joint mobilization were measured at 0 degrees and 30 degrees of shoulder abduction and were compared with those at the maximal stretching position and relaxing position. Additionally, gap distances were measured during this experiment. The strain at 30 degrees of abduction of the repaired tendon during each joint mobilization was significantly smaller than that at 0 degrees abduction (P<0.05). At 30 degrees of abduction, the strain during joint mobilization was not statistically different from that of the shoulder in the relaxing position, except during the inferior glide technique. Gap distances were 0mm at 30 degrees , while the distances were 1.06-1.46 mm at 0 degrees. Our findings suggest that joint mobilization techniques, except inferior glide, can be performed safely without significantly straining the repaired tendon at 30 degrees of abduction, if rotator cuff repair is performed at 0 degrees of abduction.     

组织工程化肌腱的构建与运动性肌腱损伤

目的:总结评价构建组织工程化肌腱生物支架材料的性能及作用,以寻找合理的肌腱替代物.方法:以"组织工程;肌腱修复;生物材料支架;运动性肌腱损伤"为中文关键词,"tissue engineering,tendon repairing,biological material scaffold,sport injury of terndon"为英文关键词,采用计算机检索1994-01/2009-12相关文章.纳入与有关运动性肌腱损伤与组织工程肌腱相关的文章;排除重复研究或Meta分析类文章.以16篇文献为主,重点对一下5个问题进行了讨论:①肌腱的组织学特征?②肌腱移植材料种类及组织工程肌腱种子细胞的来源?③如何解决同种异体肌腱细胞的免疫学反应?④如何制备与筛选特殊力学强度的支架材料?⑤伦理学问题.结果:与传统肌腱修复比较,组织工程化肌腱具有许多优点:解决了供体肌腱来源问题;组织工程化肌腱具有活力和功能,植入后可与受体肌腱愈合,永久性替换缺损肌腱;可根据缺损肌腱任意塑型,在重建功能的同时达到形态修复的目的.但是构建组织工程化肌腱,还有许多问题有待研究和解决.如何提高支架材料应用性,研制具有与正常人体肌腱组织相接近的力学性能的支架材料是其中的关键性问题.结论:模拟体内环境,解决组织工程肌腱构建的牛物材料、种子细胞,以及在体外成功构建肌腱组织是未来组织工程肌腱构建过程中的研究的重点.