足弓第2与第5跖列的肌骨系有限元模型及其临床意义

目的：建立足部内侧纵弓第2跖列与外侧纵弓第5跖列的肌骨系统有限元模型,为研究跖骨应力性骨折与相关足痛症提供生物力学工具。方法：采用中国虚拟人“女性1号”CT图像和MRI图像;应用非线性有限元方法进行生物力学分析。结果：构建了包含皮质骨、松质骨、软骨、韧带、足底腱膜、肌腱、固有肌、脂肪垫、骨髓腔与骨髓窦等10种组织的第2、第5跖列的有限元模型。足弓直立时,最大von Mises应力／应变位于第2、第5跖骨骨干与基底。各种足底软组织中,足底腱膜承担着最大张拉应力,其次为足底长韧带,足底固有肌张拉应力最小。结论：有限元预测的应力应变为研究跖骨应力性骨折,足底腱膜炎引起的慢性跟骨痛,以及足弓塌陷的发生机制提供了生物力学依据。     

微创治疗拇外翻截骨端位移与跖痛症量化关系的有限元分析

目的 明确微创治疗拇外翻截骨端位移与发生转移性跖痛症之间的关系,结合有限元进行量化分析,为手术治疗转移性跖痛症提供精准数字化依据。方法 首先基于拇外翻患者术前足部相关数据的测量建立真实的拇外翻几何模型,参考文献对志愿者各方面生物力学系数赋值,根据模拟中西医结合手法整复微创治疗拇外翻技术,对其第一跖骨进行旋转、移动及截骨,最终得到微创治疗拇外翻合并跖痛症术后有限元模型。通过模拟微创治疗拇外翻截骨端位移,利用有限元计算获取拇外翻患者手术前后的第1跖骨下与第2跖骨头下最大压力数值,分析截骨远端位移方向和位移量与发生转移性跖痛症的量化关系。结果 平衡站立时,当第1跖骨截骨远端向外侧水平位移为2 mm时,随着垂直位移的增加,第1跖骨头下压力与第2跖骨头下压力变化具有明显相关性,r值为0.954;垂直位移在2 mm时,随着水平位移的增加,第1跖骨头下压力与第2跖骨头下压力变化相关性最大,r值为-0.764。结论 微创治疗拇外翻在截骨的基础上通过正骨手法将第1跖骨截骨远端向外侧位移2～4 mm时、跖侧位移2 mm时,能够有效减轻或治愈拇外翻及并发的跖痛症,避免拇外翻术后转移性跖痛症的发生。     

虚拟中国人足底韧带结构失效后的足弓负荷机制研究

目的　建立虚拟中国人的足内侧纵弓与外侧纵弓的有限元模型,研究跖腱膜松解术或足底韧带损伤后足骨与内在肌群的生物力学特性,探讨骨性结构、足底韧带、足底腱膜、足底固有肌群之间的协调作用机制。方法　采用虚拟中国人“女性1号”CT图像和MRI图像;采用非线性有限元方法进行足弓术后或韧带损伤后的平衡直立负荷状态仿真;并应用足底固有肌群的3种被动张力（微弱、适度、强烈）模拟术后或韧带损伤后的肌肉状态。结果　建立了虚拟中国人“女性1号”足内侧纵弓第2跖列与外侧纵弓第5跖列的生物力学有限元模型,计算得到内侧纵弓和外侧纵弓在平衡直立时,韧带损伤时,固有肌群活动时的张应力矢量图、压应力矢量图和von Mises应力整体分布数据。结论　跖腱膜松解术和足底韧带损伤等增加了足纵弓von Mises应力峰值,改变了张应力与压应力的流向;而足底固有肌活动的被动张力能降低足纵弓von Mises应力集中程度,调节张应力、压应力矢量接近平衡状态,减小了并发骨折和腱炎的危险性。骨性结构、韧带、腱膜、固有肌群的内在应力具有定量的相互调节功能。     

基于三维有限元静态分析的人体足部生物力学研究

目的:建立一个基于健康人体的、系统的、具有高度几何相似性的足部三维有限元模型,并用此模型静态地分析人体双足站立相时的足部内部的生物力学特性,量化足部内部的应力/应变状况、足部内侧纵弓变化等。方法:基于志愿者右足的3维CT层切数据,对足踝系统相关组织进行几何重建及其网格划分,建立完整的有限元模型并对人体站立状态进行了静态模拟。结果:站立姿态下的足底表面接触压力分布、内部软组织应力分布以及内侧足弓的变形等人体足部生物力学特性被量化。结论:本研究中创建的三维有限元足部模型,经验证是一个正确、可靠的模型,可以帮助临床医生和其他研究人员更好的理解足部内部的许多生物力学特性。     

经皮微创跖骨远端截骨治疗拇外翻疗效观察

拇外翻是中老年人常见的后天性畸形，以女性多见，有家族性，时常合并扁平足。它是由拇跖外翻和跖骨内翻构成的三角形畸形，第一跖骨头肥大，内侧多形成滑囊，压痛明显，足前部增宽，足横弓塌陷，行走困难。传统的拇外翻手术方法有130余种，多数医生根据患者拇外翻角，跖骨间角，第一跖骨长度，内收程度等决定手术方式。我院白2006年1月～2007年4月采用经皮微创跖骨远端截骨方法治疗跖外翻16例27足取得了较好疗效，报告如下。[第一段]     

"跖袖"的解剖学特点及临床意义

目的:探讨跖袖的解剖学特点及临床意义。方法:对20只足的跖袖的构成特点进行应用解剖学观测及力学分析。结果:跖袖的构成复杂,其中收肌、展肌是维持前足横弓及籽骨系统动力平衡的关键因素,跖袖的动力平衡失调,特别是展肌与收肌通过籽骨系统导致的平衡失调是外翻形成的核心机制,在外翻畸形的发生中有着特殊的临床意义。结论:展肌与收肌移位吻合矫正外翻的新术式恢复了跖袖的正常解剖关系,重建前足横弓,恢复了前足的生理解剖结构及生物力学功能。     

内侧柱稳定手术治疗Ⅱ期成人胫后肌腱功能不全性平足的三维有限元生物力学分析

文题释义：平足内侧柱稳定手术：是指通过实施融合固定手术即融合舟楔关节或者跖楔关节,或者两者均融合来稳定足的第一跖列,恢复内侧纵弓的高度,纠正前足的旋前。 背景：平足症是足踝外科的常见病,其中Ⅱ期成人获得性平足在临床上最多见,此期的治疗最为关键。然而Ⅱ期平足内侧柱存在着不稳定,这也是造成足弓塌陷的重要原因。内侧柱稳定手术可以相当程度地纠正畸形,但是目前尚缺乏详细的生物力学实验来全面判断内侧柱稳定后对于全足带来的影响。 目的：探讨单纯内侧柱稳定手术对Ⅱ期成人获得性平足足部生物力学的影响。 方法：首先建立Ⅱa期及Ⅱb期成人获得性平足三维有限元模型,通过Geomagic软件、Solidwork软件及Abaqus软件模拟内侧柱稳定手术(舟楔关节融合､跖楔关节融合､两者均融合),将术前和术后模型模拟单倍体质量负重,比较其足底、内外侧柱骨块、内侧韧带的最大应力值,并通过测量相关参数来进行综合对比。 结果与结论：①单纯内侧柱稳定术后模拟负重时足底应力最大值均出现在第一跖骨头下方,其中Ⅱa期模型行内侧柱稳定后足底应力最大值明显增加,Ⅱb期模型内侧柱稳定后足底应力变化不明显;②内侧柱融合后相应关节的应力有所减轻,但对于第一跖列的其他关节应力反而增加了;③内侧柱融合后对于内侧韧带及足底筋膜的应力均没有减轻作用;④结果表明,单纯内侧柱稳定手术并不能降低Ⅱ期成人获得性平足内侧柱的压力,它仅可以作为联合使用的手术来稳定过度活动的关节以及纠正前足旋后畸形。 ORCID: 0000-0002-8230-1151(刘付胜华) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

介绍一种新的拇长伸肌后移术

Jone’s术(拇长伸肌后移固定于第一跖骨头,拇趾间关节融合)是矫正拇趾垂状畸形、替代胫前肌,加强足背伸功能的常用手术方法。但对儿童、尤其是10岁以下者,趾骨骨骺尚在发育,不易做关节融合,且拇长伸肌后移后亦并发拇趾下垂。作者将手术加以改进,治疗35例拇趾垂状畸形,效果满意。 手术适应症:胫前肌肌力3级以下,踝关节其它肌群基本正常,伸拇、伸趾肌肌力正常或伴有不同程度的马蹄外翻、高弓足,拇趾垂状畸形者。 手术方法: 1.跟腱延长或加跖腱膜切断,矫正马蹄和高弓畸形。 2.拇趾近端背侧纵切口,游离拇长伸肌腱并切断。在拇趾内侧找到拇展肌,游离后切断。于拇趾第一跖骨颈处前后打一骨孔,自后向前拖出拇展肌远侧断端,顶起下陷的跖骨头,将肌腱与拇长伸肌腱近侧断端缝合固定。 3.在踝关节前方做纵切口,显露拇长伸肌及     

足底软组织硬化对足部生物力学影响的三维有限元分析

目的 通过有限元方法来研究足底软组织整体硬化以及跖骨头和跟骨下方软组织局部硬化对人体足踝系统的力学影响。方法 基于健康志愿者右足的核磁共振扫描图片建立足部三维有限元模型,通过改变足底软组织的生物力学属性和人体平衡站立位时的计算仿真来分析足底软组织的生物力学问题。同时,对此志愿者进行足底压力测试来验证模型的有效性。结果 建立足踝有限元模型得到了有效的验证并完成了不同软组织属性定义下站立位的运算;在平衡站立位时足底接触压力分布状况和足踝内部一些软、硬组织的受力情况得到量化。结论 软组织硬化,特别是跖骨头和跟骨下方软组织局部硬化,对足底受压接触面积、压力峰值以及足底软组织垫所受的应力等产生了明显影响,大大增加了糖尿病患者发生足底溃烂的可能性。     

不同康复训练方法对术后拇外翻第1跖列的生物力学影响

目的研究拇外翻术后不同康复训练对第1跖列的生物力学影响。方法通过拇外翻医学影像数据建立完整的足部三维有限元模型,此模型包括骨骼、籽骨、软骨、韧带、软组织、跟腱等结构。模拟分析拇外翻患者术后被动跖屈和背屈、主动跖屈和背屈、站立位对截骨远端的生物力学影响。结果被动训练情况下,截骨远端截骨面的应力分布较均匀,且峰值(7. 78 MPa)较站立位和主动训练时大;被动训练时的最大位移量(0. 98 mm)在前后方向上大于站立位(0. 69 mm)和主动训练(0. 38 mm)的位移量。结论被动训练可促进截骨面的接触,并减少截骨端的愈合时间,有利于术后拇外翻患者的康复。     

Pain and Effusion and Quadriceps Activation and Strength

Context:

Quadriceps dysfunction is a common consequence of knee joint injury and disease, yet its causes remain elusive.

Objective:

To determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion affect the magnitude of quadriceps dysfunction.

Design:

Crossover study.

Setting:

University research laboratory.

Patients or Other Participants:

Fourteen (8 men, 6 women; age = 23.6 ± 4.8 years, height = 170.3 ± 9.16 cm, mass = 72.9 ± 11.84 kg) healthy volunteers.

Intervention(s):

All participants were tested under 4 randomized conditions: normal knee, effused knee, painful knee, and effused and painful knee.

Main Outcome Measure(s):

Quadriceps strength (Nm/kg) and activation (central activation ratio) were assessed after each condition was induced.

Results:

Quadriceps strength and activation were highest under the normal knee condition and differed from the 3 experimental knee conditions (P < .05). No differences were noted among the 3 experimental knee conditions for either variable (P > .05).

Conclusions:

Both pain and effusion led to quadriceps dysfunction, but the interaction of the 2 stimuli did not increase the magnitude of the strength or activation deficits. Therefore, pain and effusion can be considered equally potent in eliciting quadriceps inhibition. Given that pain and effusion accompany numerous knee conditions, the prevalence of quadriceps dysfunction is likely high.Key Words: arthrogenic muscle inhibition, central activation failure, voluntary activation, muscles

Key Points

• Knee pain and effusion resulted in arthrogenic muscle inhibition and weakness of the quadriceps.
• The simultaneous presence of pain and effusion did not increase the magnitude of quadriceps dysfunction.
• To reduce arthrogenic muscle inhibition and improve muscle strength, clinicians should employ interventions that target removing both pain and effusion.

Quadriceps weakness is a common consequence of traumatic knee joint injury^1,2 and chronic degenerative knee joint conditions.^3,4 Arthrogenic muscle inhibition (AMI), a neurologic decline in muscle activation, results in quadriceps weakness and hinders rehabilitation by preventing gains in strength.⁵ The inability to reverse AMI and restore muscle function can lead to decreased physical abilities,⁶ biomechanical deficits,⁷ and possibly reinjury.⁵ Furthermore, researchers^8,9 have suggested that quadriceps weakness resulting from AMI may place patients at risk for developing osteoarthritis in the knee. In light of the substantial influence of quadriceps AMI on these clinically relevant outcomes, we need to improve our understanding of the factors that contribute to this neurologic decline in muscle activity so efforts to target and reverse it can be implemented and gains in strength can be achieved more easily.Joint injury and disease are accompanied by numerous sequelae (ie, pain, swelling, tissue damage, inflammation), so ascertaining which one ultimately leads to neurologic muscle dysfunction is difficult. Whereas a joint effusion can result in AMI,^10–12 the effects of pain are less understood despite many clinicians attributing AMI to pain. Using techniques that introduce knee pain without accompanying injury may provide insights into the role of pain in eliciting AMI.The degree of knee joint damage may play a role in the quantity of AMI that manifests. Hurley et al^13,14 demonstrated that quadriceps AMI, measured using an interpolated-twitch technique, was greater in patients with extensive traumatic knee injury (eg, fractured tibial plateau, ruptured medial collateral ligament, and medial meniscectomy) than patients with isolated joint trauma (ie, isolated anterior cruciate ligament [ACL] rupture). Similarly, patients with more knee joint symptoms (ie, greater number of symptoms and increased severity of symptoms) may present with greater magnitudes of quadriceps inhibition. Recently, investigators¹⁵ have suggested that patients with more pain display less quadriceps strength, supporting this tenet. Given that effusion and pain often present simultaneously with joint injuries and diseases, such as ACL injury and osteoarthritis, examining both the isolated and cumulative effects of these sequelae appears warranted to determine if they influence the magnitude of muscle inhibition.Experimental joint-effusion and pain models are safe and effective experimental methods that allow for the isolated examination of their effects on muscle function. The effusion model, whereby sterile saline is injected directly into the knee joint capsule,⁷ produces a clinically relevant magnitude of the joint effusion that may be present with traumatic injury. Effusion is thought to activate group II afferents responding to stretch or pressure,^16–18 which in turn may facilitate group Ib interneurons and result in quadriceps AMI.⁵ The pain model involves injecting hypertonic saline into the infrapatellar fat pad to produce anteromedial knee pain similar to that described in patients with patellofemoral pain syndrome.¹⁹ Pain is considered to initiate AMI through activation of group III and IV afferents that act as nocioceptors to signal damage or potential damage to joint structures.^16–18 The firing of these afferents then may lead to facilitation of group Ib interneurons, the flexion reflex, or the gamma loop, ultimately resulting in quadriceps inhibition.²⁰ Thus, these models allow us to create symptoms that are associated with knee injury and have the added benefit of providing a way to examine their effects in isolation.Therefore, the purpose of our study was to determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion would affect the magnitude of quadriceps dysfunction. We hypothesized that pain alone would result in quadriceps inhibition and that the magnitude of inhibition would be greater when effusion and pain were present simultaneously.     

即早基因c-fos与脑血管病及学习记忆

即早基因c-fos是广泛存在于原核细胞和真核细胞的高度保守基因.在正常情况下,c-fos基因参与细胞生长、分化、信息传递、学习和记忆等生理过程,而在病理情况下c-fos基因表达及调控变化与多种疾病的发生和发展有关.C-fos在中枢神经系统的某些部位可有基础水平的表达,但表达很低,当受到如脑缺血、脑出血、痫性发作、应激等刺激后,其在数十分钟内做出反应,在对外界刺激-转录耦联的信忠传递过程中起着核内第三信使的重要作用.     

自主创新学习与问题探究教学改革的探索与实践

<正>人体解剖学与组织学胚胎学是高职护理及助产专业的学生接触最早而又重要的医学基础核心课程。鉴于目前高职护理及助产专业的教学内容多,课时少等难题,教与学的矛盾日益突出。因此,如何在有限的时间内既保证教学体系的完整性,又能解决时间与内容冲突的矛盾,从而使医学生对所学内容真正达到"必须、够用",是授课教师面临的严峻挑战。同时,顺应医学终身教育发展的需求,提高医学生自主学习的能力,